diff --git a/changelog.d/1426-fire-intensity-filter.md b/changelog.d/1426-fire-intensity-filter.md
new file mode 100644
index 000000000..aacc37d71
--- /dev/null
+++ b/changelog.d/1426-fire-intensity-filter.md
@@ -0,0 +1,12 @@
+- Color every Active Fires detection by fire radiative power on a six-stop
+  ember → white-hot ramp (ember · red · flame · orange · gold · white-hot at
+  0 · 5 · 20 · 50 · 100 · 300 MW, brighter as power rises), and add a
+  log-scale minimum-FRP slider whose track is the ramp, an All / Nominal+ /
+  High confidence switch and an "N of M shown" counter to the layer row. Far
+  zoom shows a Snap Map–style heatmap in the same colors instead of squares,
+  one distinct spot per fire, empty where nothing burns, and cross-fades with
+  the markers around 4,500 km with no gap, keeping weak fires as markers. The filter applies once before
+  rendering, so markers, cards, the heatmap, context and the top-fires query
+  agree; share links keep it (`w` token: `f`, `c`), and `get_active_fires`
+  takes matching `min_frp_mw` and `confidence` arguments. Default 0 MW / All
+  (gekh, #1426).
diff --git a/changelog.d/1535-fires-empty-heat-reenable.md b/changelog.d/1535-fires-empty-heat-reenable.md
new file mode 100644
index 000000000..a862a7b56
--- /dev/null
+++ b/changelog.d/1535-fires-empty-heat-reenable.md
@@ -0,0 +1,2 @@
+- Keep retained Active Fires heat imagery hidden when an empty filtered layer is
+  re-enabled while a new snapshot is pending (radianx, #1535).
diff --git a/changelog.d/1561-chat-autocomplete-arabic-marks.md b/changelog.d/1561-chat-autocomplete-arabic-marks.md
new file mode 100644
index 000000000..b49cd0e86
--- /dev/null
+++ b/changelog.d/1561-chat-autocomplete-arabic-marks.md
@@ -0,0 +1,3 @@
+- Chat autocomplete finds Arabic suggestions typed without short vowels or
+  shadda, so «تتبع» now suggests «اعرض تتبّع الرحلات المباشر»
+  (German, @gekh, #1561).
diff --git a/docs/CURRENT-STATE.md b/docs/CURRENT-STATE.md
index ab6dba5b0..81e71655c 100644
--- a/docs/CURRENT-STATE.md
+++ b/docs/CURRENT-STATE.md
@@ -2323,6 +2323,62 @@ Generated style sliders use the same name as their visible parameter label.
 The first-run suppression checkbox keeps its native wrapping label, so its
 accessible name remains "Don't show this again". Control behavior is unchanged.
 
+## Active Fires intensity filter and color ramp
+
+Every FIRMS detection is colored by fire radiative power on a six-stop ember →
+white-hot ramp: dark ember from 0 MW, red from 5, flame from 20, orange from
+50, gold from 100 and pale white-hot from 300 MW (`FRP_RAMP` in
+`src/data/firmsIntensity.js`). Each stop is lighter than the one below and
+none is a cold hue, so the brightest marks are the strongest fires; ~90% of
+detections are under 20 MW and stay dim red. Glow sprites and fire-card
+accents read that ramp; confidence and brightness do not affect the color.
+
+At far zoom (camera above ~4,500 km) the layer drapes a Snap Map–style
+heatmap instead of individual markers: the shown detections are linearly binned
+(each detection's weight shared between the four nearest pixel centres, so spots
+sit at the true position and stay round) on a
+global 4096 × 2048 grid (≈10 km per pixel), each weighted by its FRP in megawatts (so heat is
+radiated power, and raising the FRP slider does not dim areas where strong fires
+burn, and a cluster of detections reads brighter than one), Gaussian-blurred by one
+pixel so each fire stays a distinct spot about the size of its marker,
+normalized on a log scale against the 99.5th percentile and mapped through the
+same hues, from a bright red edge through orange and gold to a pale
+white-hot core. The edge starts more than half opaque, so regions far below
+the hottest ones still read over forest and savanna imagery. Nothing is painted where
+nothing burns (`src/data/firmsHeatRaster.js`). It is one full-globe imagery
+tile on the active imagery host (`src/layers/firms/heatImagery.js`), rebuilt
+on each data refresh or filter change (the first far-band paint at once,
+later ones 150 ms after the last change). Heatmap and markers are both kept
+built at every zoom and cross-fade by camera height between 3,600 and
+5,400 km, every frame, so a fast zoom never shows a gap: the heatmap fades by
+imagery `alpha` (a hidden Cesium imagery layer is unmapped from the globe
+tiles and re-mapped late when shown), the markers by sprite alpha, and the
+marker collection is hidden once the heatmap is whole. The 750–4,500 km
+markers band draws up to 40,000 detections (the strongest in the padded
+view), so the weak fires the heatmap shows stay on screen as markers when it
+fades out; it reads each marker's already-built anchor instead of the ground
+floor cache, which only the close band warms. "N FIRES" cards from a 2° / 1° aggregation still label the hottest
+areas; their accent is the strongest fire's FRP color.
+Re-enabling Active Fires keeps the retained heat imagery hidden when the current
+filtered set is empty, including while a new snapshot is pending.
+
+The Active Fires row carries a "Fire intensity (FRP)" slider on a log scale
+whose track is painted with the ramp and ticked at the same six values (its
+value reads "All" or "≥ N MW"), a "Confidence" switch with All / Nominal+ /
+High, and an "N of M shown" counter. The default is 0 MW and
+All, because many of the strongest detections are rated low confidence. The
+filter runs once in `ingestion.applyFilter()` before rendering, so markers,
+cards, the heatmap, the shared context store, the top-fires query and the
+analyst records all see one filtered set; a selected fire that no longer passes
+is deselected. The layer state keeps both options under the `w` (`local-firms`)
+share token as `f` (whole megawatts, 0–10,000) and `c` (`a`, `n`, `h`),
+including the short share codec; a link without them restores the defaults.
+
+The `get_active_fires` tool accepts its own `min_frp_mw` and `confidence`
+(`all`, `nominal`, `high`) arguments, independent of the panel's setting, and
+names the applied criteria in its notes. Stale-snapshot and missing-source
+reporting are unchanged.
+
 ## FIRMS source status
 
 The FIRMS CSV parser rejects impossible acquisition calendar dates before the proxy filters records to the trailing 24 hours, while retaining valid UTC acquisition times.
diff --git a/scripts/format-scope.json b/scripts/format-scope.json
index 5a734bb12..2c589d8cc 100644
--- a/scripts/format-scope.json
+++ b/scripts/format-scope.json
@@ -420,6 +420,7 @@
   "src/layers/firms/cards.js",
   "src/layers/firms/index.js",
   "src/layers/firms/ingestion.js",
+  "src/layers/firms/heatVisibility.test.mjs",
   "src/layers/firms/lifecycle.js",
   "src/layers/firms/model.js",
   "src/layers/firms/policy.js",
@@ -1210,6 +1211,10 @@
   "src/data/headingDegrees.test.mjs",
   "src/data/distanceFormat.test.mjs",
   "src/sources/adsbFields.test.mjs",
+  "src/data/firmsIntensity.js",
+  "src/data/firmsIntensity.test.mjs",
+  "src/ui/layerPanel/RowSwitch.vue",
+  "src/ui/layerPanel/RowSlider.vue",
   "src/sources/phaseTiming.test.mjs",
   "scripts/build-census-places.mjs",
   "src/data/placeBoundaries.test.mjs",
diff --git a/scripts/package-boundaries.json b/scripts/package-boundaries.json
index a774993b2..d008ceaaa 100644
--- a/scripts/package-boundaries.json
+++ b/scripts/package-boundaries.json
@@ -685,6 +685,8 @@
       "src/ui/rail/classToggle.js",
       "src/ui/rail/focusSafeChildren.js",
       "src/ui/layerPanel/RowText.vue",
+      "src/ui/layerPanel/RowSwitch.vue",
+      "src/ui/layerPanel/RowSlider.vue",
       "src/ui/railTimeline.js",
       "src/ui/clearLayersControl.js",
       "src/loadingFeedback.js",
@@ -722,7 +724,8 @@
       "src/ui/kit/UiButton.vue",
       "src/ui/kit/UiBadge.vue",
       "src/ui/rail/fieldValue.js",
-      "src/ui/kit/UiSlider.js"
+      "src/ui/kit/UiSlider.js",
+      "src/ui/kit/UiSegmented.vue"
     ],
     "external": ["vue"]
   },
@@ -946,6 +949,7 @@
       "src/data/detectionPolicy.js",
       "src/data/installationFeedback.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateCoordinator.js",
       "src/data/layerStateTokenReservations.json",
@@ -1018,6 +1022,8 @@
       "src/ui/rail/classToggle.js",
       "src/ui/rail/focusSafeChildren.js",
       "src/ui/layerPanel/RowText.vue",
+      "src/ui/layerPanel/RowSwitch.vue",
+      "src/ui/layerPanel/RowSlider.vue",
       "src/ui/railTimeline.js",
       "src/ui/layers.js",
       "src/ui/leftPanelRail.js",
@@ -1141,7 +1147,8 @@
       "src/ui/kit/UiBadge.vue",
       "src/ui/stores/globeActions.js",
       "src/ui/stores/recording.js",
-      "src/ui/i18n.js"
+      "src/ui/i18n.js",
+      "src/ui/kit/UiSegmented.vue"
     ],
     "external": ["cesium", "vue", "pinia", "vue-i18n"]
   },
@@ -1310,6 +1317,7 @@
       "src/data/contactMatch.js",
       "src/data/iconOrientation.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateTokenReservations.json",
       "src/data/modelVisualAnchor.js",
@@ -1372,6 +1380,7 @@
       "src/data/contactMatch.js",
       "src/data/iconOrientation.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateTokenReservations.json",
       "src/data/modelVisualAnchor.js",
@@ -1425,6 +1434,7 @@
       "src/data/contactMatch.js",
       "src/data/iconOrientation.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateCoordinator.js",
       "src/data/layerStateTokenReservations.json",
@@ -1526,6 +1536,8 @@
     "exports": ["./layers/firms"],
     "modules": [
       "src/data/firmsAdapt.js",
+      "src/data/firmsIntensity.js",
+      "src/data/firmsHeatRaster.js",
       "src/data/firmsLabels.js",
       "src/data/iconOrientation.js",
       "src/layers/firms/anchors.js",
@@ -1537,6 +1549,7 @@
       "src/layers/firms/policy.js",
       "src/layers/firms/queries.js",
       "src/layers/firms/rendering.js",
+      "src/layers/firms/heatImagery.js",
       "src/layers/firms/selection.js",
       "src/layers/firms/source.js",
       "src/layers/firms/state.js",
@@ -2000,6 +2013,7 @@
     "modules": [
       "src/data/iconOrientation.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateTokenReservations.json",
       "src/data/radioCountry.js",
@@ -2372,6 +2386,8 @@
       "src/data/fireAnchors.js",
       "src/data/firmsAdapt.js",
       "src/data/firmsHeatmap.js",
+      "src/data/firmsIntensity.js",
+      "src/data/firmsHeatRaster.js",
       "src/data/firmsLabels.js",
       "src/data/flights.js",
       "src/data/flowMatch.js",
@@ -2533,6 +2549,7 @@
       "src/layers/firms/policy.js",
       "src/layers/firms/queries.js",
       "src/layers/firms/rendering.js",
+      "src/layers/firms/heatImagery.js",
       "src/layers/firms/selection.js",
       "src/layers/firms/source.js",
       "src/layers/firms/state.js",
@@ -2794,6 +2811,8 @@
       "src/ui/rail/classToggle.js",
       "src/ui/rail/focusSafeChildren.js",
       "src/ui/layerPanel/RowText.vue",
+      "src/ui/layerPanel/RowSwitch.vue",
+      "src/ui/layerPanel/RowSlider.vue",
       "src/ui/railTimeline.js",
       "src/ui/layers.js",
       "src/ui/leftPanelRail.js",
@@ -3333,6 +3352,8 @@
       "src/data/detectionDraw.js",
       "src/data/detectionPolicy.js",
       "src/data/firmsAdapt.js",
+      "src/data/firmsIntensity.js",
+      "src/data/firmsHeatRaster.js",
       "src/data/firmsLabels.js",
       "src/data/flowMatch.js",
       "src/data/focusDeemphasis.js",
@@ -3464,6 +3485,7 @@
       "src/layers/firms/policy.js",
       "src/layers/firms/queries.js",
       "src/layers/firms/rendering.js",
+      "src/layers/firms/heatImagery.js",
       "src/layers/firms/selection.js",
       "src/layers/firms/source.js",
       "src/layers/firms/state.js",
@@ -3987,6 +4009,7 @@
       "src/i18n/marker.js",
       "src/data/installationFeedback.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateCoordinator.js",
       "src/data/layerStateTokenReservations.json",
@@ -4704,6 +4727,7 @@
       "src/styles/surveillance.js",
       "src/styles/thermal.js",
       "src/view/index.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateTokenReservations.json",
       "src/data/idSwitches.js",
@@ -4825,6 +4849,8 @@
       "src/tools/queries/brief.js",
       "src/tools/queries/maritime.js",
       "src/tools/queries/share.js",
+      "src/data/firmsIntensity.js",
+      "src/data/firmsAdapt.js",
       "src/data/idSwitches.js",
       "src/data/vesselTypes.js",
       "src/data/layerState.js",
@@ -4959,6 +4985,7 @@
     "modules": [
       "src/view/index.js",
       "src/data/idSwitches.js",
+      "src/data/firmsIntensity.js",
       "src/data/layerState.js",
       "src/data/layerStateTokenReservations.json",
       "src/visualStylePolicy.js"
diff --git a/src/data/firmsCards.test.mjs b/src/data/firmsCards.test.mjs
index 3928051db..9d6157324 100644
--- a/src/data/firmsCards.test.mjs
+++ b/src/data/firmsCards.test.mjs
@@ -45,7 +45,7 @@ test('buildFireCard: title carries FRP, detail carries conf/age/satellite', () =
   assert.equal(card.details.length, 1);
   assert.equal(card.details[0], 'high · 2h · N20');
   assert.equal(card.selected, false);
-  assert.equal(card.accent, accentForSeverity('red'), 'FRP 1520 is red-hot');
+  assert.equal(card.accent, accentForSeverity('white-hot'), 'FRP 1520 is white-hot');
   assert.deepEqual(card.position, { x: 1, y: 2, z: 3 }, 'uses the candidate position untouched');
 });
 
@@ -69,11 +69,27 @@ test('buildFireCard: power that rounds to 10 MW drops the decimal', () => {
   assert.equal(selected.title, 'FIRE · 10 MW');
 });
 
-test('buildFireCard: SNPP satellite code renders as SNPP, weak fire is not red', () => {
+test('buildFireCard: SNPP satellite code renders as SNPP, weak fire is an ember', () => {
   const card = buildFireCard({ fire: fire({ satellite: 'N', frp: 0.8, confidence: 0.3 }), position: {} }, NOW);
   assert.match(card.details[0], /SNPP$/);
   assert.equal(card.title, '▲ 0.8 MW');
-  assert.notEqual(card.accent, accentForSeverity('red'));
+  assert.equal(card.accent, accentForSeverity('ember'));
+});
+
+test('buildFireCard: accent steps through the FRP ramp at 5 · 20 · 50 · 100 · 300 MW', () => {
+  const accentAt = (frp) =>
+    buildFireCard({ fire: fire({ frp }), position: {} }, NOW).accent;
+  assert.equal(accentAt(4.9), accentForSeverity('ember'));
+  assert.equal(accentAt(5), accentForSeverity('red'));
+  assert.equal(accentAt(20), accentForSeverity('flame'));
+  assert.equal(accentAt(50), accentForSeverity('orange'));
+  assert.equal(accentAt(100), accentForSeverity('gold'));
+  assert.equal(accentAt(300), accentForSeverity('white-hot'));
+  // Confidence never moves the color: a low-confidence 864 MW fire stays red.
+  assert.equal(
+    buildFireCard({ fire: fire({ frp: 864, confidence: 0.3 }), position: {} }, NOW).accent,
+    accentForSeverity('white-hot'),
+  );
 });
 
 test('buildSelectedFireCard: full detail card with coords, selected flag, no fade', () => {
@@ -93,12 +109,12 @@ test('buildCellCard: plural noun, max FRP and newest age, accent passthrough', (
   const candidate = {
     cell: { count: 14, maxFrp: 210.4, newestAcqMs: NOW - 3 * H, night: 2 },
     position: { x: 0, y: 0, z: 0 },
-    accent: accentForSeverity('orange'),
+    accent: accentForSeverity('gold'),
   };
   const card = buildCellCard(candidate, NOW);
   assert.equal(card.title, '14 FIRES');
   assert.equal(card.details[0], 'max 210 MW · new 3h');
-  assert.equal(card.accent, accentForSeverity('orange'));
+  assert.equal(card.accent, accentForSeverity('gold'));
 });
 
 test('buildCellCard: the count picks the plural form of the language', () => {
@@ -150,7 +166,7 @@ test('buildCellCard: singular noun and missing-age omission', () => {
   const card = buildCellCard(candidate, NOW);
   assert.equal(card.title, '1 FIRE');
   assert.equal(card.details[0], 'max 9.9 MW');
-  assert.equal(card.accent, accentForSeverity('yellow'), 'missing accent defaults to yellow');
+  assert.equal(card.accent, accentForSeverity('ember'), 'missing accent defaults to the weakest stop');
 });
 
 test('FIRMS host policy keeps ambient cards bounded and selected cards protected', () => {
diff --git a/src/data/firmsHeatRaster.js b/src/data/firmsHeatRaster.js
new file mode 100644
index 000000000..6704cf6e2
--- /dev/null
+++ b/src/data/firmsHeatRaster.js
@@ -0,0 +1,209 @@
+/**
+ * Snap Map–style heat raster for the Active Fires far-zoom bands: detections
+ * are linearly binned on an equirectangular grid (row 0 = north, column
+ * 0 = 180°W), blurred, normalized on a log scale and mapped through
+ * HEAT_PALETTE. Pure: no Cesium, no DOM, so the whole pipeline is unit-tested
+ * in node.
+ */
+
+/** Below this normalized heat nothing is painted: empty land stays empty. */
+export const HEAT_FLOOR = 0.03;
+
+/**
+ * The FRP marker ramp as a continuous glow, from a red edge through orange
+ * and gold to a pale white-hot core. The edge is a bright red, not the
+ * markers' dark ember, and starts more than half opaque: most of the world
+ * sits low on a scale set by the hottest regions, and a dark translucent red
+ * vanishes into forest and savanna imagery.
+ */
+export const HEAT_PALETTE = Object.freeze([
+  { at: 0.0, rgb: [232, 58, 30], alpha: 0 },
+  { at: 0.08, rgb: [232, 58, 30], alpha: 0.58 },
+  { at: 0.25, rgb: [242, 86, 34], alpha: 0.7 },
+  { at: 0.45, rgb: [248, 122, 40], alpha: 0.76 },
+  { at: 0.65, rgb: [252, 166, 52], alpha: 0.82 },
+  { at: 0.82, rgb: [254, 208, 92], alpha: 0.87 },
+  { at: 1.0, rgb: [255, 245, 190], alpha: 0.92 },
+]);
+
+export function heatColorAt(t) {
+  if (!(t > HEAT_FLOOR)) return [0, 0, 0, 0];
+  const v = Math.min(1, t);
+  let i = 1;
+  while (i < HEAT_PALETTE.length - 1 && HEAT_PALETTE[i].at < v) i += 1;
+  const a = HEAT_PALETTE[i - 1];
+  const b = HEAT_PALETTE[i];
+  const k = (v - a.at) / (b.at - a.at || 1);
+  const mix = (p, q) => Math.round(p + (q - p) * k);
+  return [
+    mix(a.rgb[0], b.rgb[0]),
+    mix(a.rgb[1], b.rgb[1]),
+    mix(a.rgb[2], b.rgb[2]),
+    Math.round((a.alpha + (b.alpha - a.alpha) * k) * 255),
+  ];
+}
+
+/** Weight of a detection with no or zero FRP, in megawatts. */
+export const HEAT_MIN_WEIGHT_MW = 0.5;
+
+/**
+ * Heat is radiated power, not a head count: each detection adds its FRP in
+ * megawatts. Weak fires carry little power, so raising the minimum-FRP slider
+ * removes most detections without dimming the areas where strong fires burn
+ * (a count-based heat collapsed there and the hot spots faded).
+ */
+const defaultWeight = (fire) =>
+  Math.max(HEAT_MIN_WEIGHT_MW, Number(fire.frp) || 0);
+
+/**
+ * Linear binning (Wand 1994): each detection's weight is shared between the
+ * four pixel centres around it in proportion to closeness, instead of
+ * dropping whole into one pixel. Spots then sit at the true position rather
+ * than snapping by up to half a pixel (~10 km), and a lone weak fire blurs
+ * into a round spot instead of a square or a plus sign. Longitude wraps;
+ * rows beyond the poles fold back onto the edge row.
+ */
+export function binFires(fires, { width, height, weight = defaultWeight }) {
+  const grid = new Float32Array(width * height);
+  const row = (y) => Math.min(height - 1, Math.max(0, y)) * width;
+  const col = (x) => ((x % width) + width) % width;
+  for (const fire of fires) {
+    if (!Number.isFinite(fire.lat) || !Number.isFinite(fire.lon)) continue;
+    const fx = ((fire.lon + 180) / 360) * width - 0.5;
+    const fy = ((90 - fire.lat) / 180) * height - 0.5;
+    const x0 = Math.floor(fx);
+    const y0 = Math.floor(fy);
+    const tx = fx - x0;
+    const ty = fy - y0;
+    const w = weight(fire);
+    const top = row(y0);
+    const bottom = row(y0 + 1);
+    const left = col(x0);
+    const right = col(x0 + 1);
+    grid[top + left] += w * (1 - tx) * (1 - ty);
+    grid[top + right] += w * tx * (1 - ty);
+    grid[bottom + left] += w * (1 - tx) * ty;
+    grid[bottom + right] += w * tx * ty;
+  }
+  return grid;
+}
+
+function kernel(sigma) {
+  const radius = Math.max(1, Math.ceil(sigma * 3));
+  const k = new Float32Array(radius * 2 + 1);
+  let sum = 0;
+  for (let i = -radius; i <= radius; i++) {
+    k[i + radius] = Math.exp(-(i * i) / (2 * sigma * sigma));
+    sum += k[i + radius];
+  }
+  for (let i = 0; i < k.length; i++) k[i] /= sum;
+  return { k, radius };
+}
+
+export function blurGaussian(grid, width, height, sigma) {
+  const { k, radius } = kernel(sigma);
+  const tmp = new Float32Array(grid.length);
+  const out = new Float32Array(grid.length);
+  for (let y = 0; y < height; y++) {
+    const row = y * width;
+    for (let x = 0; x < width; x++) {
+      const v = grid[row + x];
+      if (v === 0) continue;
+      for (let i = -radius; i <= radius; i++) {
+        const xx = (((x + i) % width) + width) % width; // longitude wraps
+        tmp[row + xx] += v * k[i + radius];
+      }
+    }
+  }
+  for (let y = 0; y < height; y++) {
+    for (let x = 0; x < width; x++) {
+      const v = tmp[y * width + x];
+      if (v === 0) continue;
+      for (let i = -radius; i <= radius; i++) {
+        const yy = Math.min(height - 1, Math.max(0, y + i)); // poles clamp
+        out[yy * width + x] += v * k[i + radius];
+      }
+    }
+  }
+  return out;
+}
+
+/** Bins of the log-density histogram used to find the reference quantile. */
+const QUANTILE_BINS = 4096;
+
+/**
+ * The p-quantile of the non-zero values, from a histogram of log1p(value):
+ * one linear pass instead of sorting ~350k burning pixels (a sort cost
+ * 200 ms+ and dominated the build). Bin width on the log axis is
+ * max/4096, far finer than the 256-step palette it feeds.
+ */
+function percentileOfNonZero(values, p) {
+  let count = 0;
+  let max = 0;
+  for (let i = 0; i < values.length; i++) {
+    const v = values[i];
+    if (v > 0) {
+      count += 1;
+      if (v > max) max = v;
+    }
+  }
+  if (!count) return 0;
+  const logMax = Math.log1p(max);
+  const bins = new Uint32Array(QUANTILE_BINS);
+  const toBin = (QUANTILE_BINS - 1) / logMax;
+  for (let i = 0; i < values.length; i++) {
+    const v = values[i];
+    if (v > 0) bins[Math.floor(Math.log1p(v) * toBin)] += 1;
+  }
+  const target = Math.floor(p * (count - 1));
+  let seen = 0;
+  for (let b = 0; b < QUANTILE_BINS; b++) {
+    seen += bins[b];
+    if (seen > target) return Math.expm1((b + 1) / toBin);
+  }
+  return max;
+}
+
+/** HEAT_PALETTE sampled at 256 steps, so the per-pixel walk is one lookup. */
+const LUT_STEPS = 256;
+let paletteLut = null;
+function heatLut() {
+  if (!paletteLut) {
+    paletteLut = new Uint8ClampedArray(LUT_STEPS * 4);
+    for (let i = 0; i < LUT_STEPS; i++) {
+      paletteLut.set(heatColorAt(i / (LUT_STEPS - 1)), i * 4);
+    }
+  }
+  return paletteLut;
+}
+
+export function buildHeatRaster(
+  fires,
+  { width, height, sigmaPx, percentile = 0.995 },
+) {
+  const density = blurGaussian(
+    binFires(fires, { width, height }),
+    width,
+    height,
+    sigmaPx,
+  );
+  const reference = percentileOfNonZero(density, percentile);
+  const rgba = new Uint8ClampedArray(width * height * 4);
+  if (reference > 0) {
+    const lut = heatLut();
+    const scale = (LUT_STEPS - 1) / Math.log1p(reference);
+    for (let i = 0; i < density.length; i++) {
+      const d = density[i];
+      if (d <= 0) continue;
+      const step = Math.min(LUT_STEPS - 1, Math.round(Math.log1p(d) * scale));
+      const l = step * 4;
+      if (lut[l + 3] === 0) continue;
+      const o = i * 4;
+      rgba[o] = lut[l];
+      rgba[o + 1] = lut[l + 1];
+      rgba[o + 2] = lut[l + 2];
+      rgba[o + 3] = lut[l + 3];
+    }
+  }
+  return { width, height, rgba, reference };
+}
diff --git a/src/data/firmsHeatRaster.test.mjs b/src/data/firmsHeatRaster.test.mjs
new file mode 100644
index 000000000..754493754
--- /dev/null
+++ b/src/data/firmsHeatRaster.test.mjs
@@ -0,0 +1,118 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  HEAT_MIN_WEIGHT_MW,
+  HEAT_PALETTE,
+  heatColorAt,
+  binFires,
+  blurGaussian,
+  buildHeatRaster,
+} from './firmsHeatRaster.js';
+
+const fire = (lat, lon, frp = 10) => ({ lat, lon, frp });
+
+test('palette runs ember to white-hot and starts fully transparent', () => {
+  assert.equal(HEAT_PALETTE[0].at, 0);
+  assert.equal(HEAT_PALETTE.at(-1).at, 1);
+  assert.deepEqual(heatColorAt(0), [0, 0, 0, 0]);
+  assert.equal(heatColorAt(0.01)[3], 0, 'below the floor nothing is painted');
+  const low = heatColorAt(0.15);
+  const high = heatColorAt(1);
+  assert.ok(low[0] > low[1] && low[1] > low[2], 'low heat is red');
+  assert.ok(low[3] >= 0.5 * 255, 'low heat stays visible on any imagery');
+  assert.ok(high[1] > low[1] && high[2] > low[2], 'the core is paler');
+  assert.ok(high[3] > low[3], 'hotter is more opaque');
+  for (let i = 1; i <= 100; i++) {
+    const [r, , b] = heatColorAt(i / 100);
+    assert.ok(r >= b, `no cold hue at ${i}%`);
+  }
+});
+
+test('binFires puts a detection at a pixel centre wholly in that pixel', () => {
+  // 4×2 grid: pixel centres at lon −135/−45/45/135, lat ±45.
+  const grid = binFires([fire(45, -135, 1), fire(-45, 135, 1)], {
+    width: 4,
+    height: 2,
+  });
+  assert.equal(grid[0], 1, 'north-west pixel');
+  assert.equal(grid[7], 1, 'south-east pixel');
+  assert.equal(
+    grid.reduce((a, b) => a + b, 0),
+    2,
+  );
+});
+
+test('binFires shares a detection between the pixels around it', () => {
+  const between = binFires([fire(45, 0, 1)], { width: 4, height: 2 });
+  assert.equal(between[1], 0.5, 'half to the pixel west of it');
+  assert.equal(between[2], 0.5, 'half to the pixel east of it');
+  const quarter = binFires([fire(45, -112.5, 1)], { width: 4, height: 2 });
+  assert.equal(quarter[0], 0.75, 'closer centre takes more');
+  assert.equal(quarter[1], 0.25);
+  const wrapped = binFires([fire(45, 180, 1)], { width: 4, height: 2 });
+  assert.equal(wrapped[3], 0.5, 'the antimeridian wraps');
+  assert.equal(wrapped[0], 0.5);
+  const polar = binFires([fire(90, -135, 1)], { width: 4, height: 2 });
+  assert.equal(polar[0], 1, 'beyond the last row folds back onto it');
+});
+
+test('binFires weights each detection by its radiative power', () => {
+  const grid = binFires(
+    [fire(45, 45, 250), fire(45, 45, 0), fire(45, 45, Number.NaN)],
+    { width: 4, height: 2 },
+  );
+  assert.equal(grid[2], 250 + 2 * HEAT_MIN_WEIGHT_MW);
+});
+
+test('filtering out weak fires keeps a strong fire hot', () => {
+  const strong = fire(0.1, 0.1, 300);
+  const weak = Array.from({ length: 40 }, () => fire(0.1, 0.1, 2));
+  const reference = Array.from({ length: 10 }, () => fire(20.1, 20.1, 100));
+  const options = { width: 360, height: 180, sigmaPx: 2 };
+  const pixel = ((90 - 0.1) | 0) * 360 + ((0.1 + 180) | 0);
+  const red = (r) => r.rgba[pixel * 4];
+  const alpha = (r) => r.rgba[pixel * 4 + 3];
+  const unfiltered = buildHeatRaster([strong, ...weak, ...reference], options);
+  const filtered = buildHeatRaster([strong, ...reference], options);
+  assert.ok(alpha(filtered) > 0);
+  assert.ok(
+    alpha(filtered) >= alpha(unfiltered) * 0.9,
+    `alpha ${alpha(unfiltered)} -> ${alpha(filtered)}`,
+  );
+  assert.ok(
+    red(filtered) >= red(unfiltered) * 0.9,
+    `red ${red(unfiltered)} -> ${red(filtered)}`,
+  );
+});
+
+test('blurGaussian keeps mass and wraps across the antimeridian', () => {
+  const w = 16;
+  const h = 8;
+  const grid = new Float32Array(w * h);
+  grid[3 * w + 0] = 1;
+  const out = blurGaussian(grid, w, h, 1.5);
+  const sum = out.reduce((a, b) => a + b, 0);
+  assert.ok(Math.abs(sum - 1) < 1e-3, `mass ${sum}`);
+  assert.ok(out[3 * w + (w - 1)] > 0, 'spills to the east edge');
+});
+
+test('buildHeatRaster is transparent where there are no fires', () => {
+  const r = buildHeatRaster([fire(40, -120), fire(40.1, -120.1)], {
+    width: 360,
+    height: 180,
+    sigmaPx: 2,
+  });
+  assert.equal(r.rgba.length, 360 * 180 * 4);
+  const alphaAt = (lat, lon) => {
+    const x = Math.floor(((lon + 180) / 360) * 360);
+    const y = Math.floor(((90 - lat) / 180) * 180);
+    return r.rgba[(y * 360 + x) * 4 + 3];
+  };
+  assert.ok(alphaAt(40, -120) > 0, 'blob over the fires');
+  assert.equal(alphaAt(-30, 60), 0, 'empty far away');
+});
+
+test('buildHeatRaster with no fires is fully transparent', () => {
+  const r = buildHeatRaster([], { width: 8, height: 4, sigmaPx: 1 });
+  assert.ok(r.rgba.every((v) => v === 0));
+});
diff --git a/src/data/firmsIntensity.js b/src/data/firmsIntensity.js
new file mode 100644
index 000000000..0b14dd3bd
--- /dev/null
+++ b/src/data/firmsIntensity.js
@@ -0,0 +1,212 @@
+/**
+ * @module firmsIntensity
+ * @description Fire intensity policy shared by the Active Fires layer and the
+ * agent fire tool: the six-stop ember → white-hot FRP color ramp, the log-scale
+ * slider that doubles as its legend, and the one filter every consumer
+ * (markers, cards, heat cells, the top-fires query, `get_active_fires`) runs
+ * before anything is rendered or selected. Pure — no Cesium, no DOM.
+ *
+ * The ramp (`FRP_RAMP`, stepped, not interpolated) runs like a fire cooling
+ * down: a dim ember for weak fires through red, orange and gold to a pale
+ * white-hot core, lightness rising with power, so the brightest marks are the
+ * strongest fires. No cold hues: ~90% of detections are under 20 MW and a
+ * blue start painted most of the map blue. The thresholds are GEV's own, set
+ * on a real week's percentiles so every color appears: Portolan's
+ * 0/10/50/200/500/1000 MW leaves one hottest fire a week (HAL-675).
+ */
+
+/**
+ * Stepped FRP ramp, weakest first. A detection takes the LAST stop whose
+ * `minFrp` it reaches. Names key the glow-sprite cache and the card accents.
+ */
+export const FRP_RAMP = Object.freeze([
+  Object.freeze({ name: 'ember', minFrp: 0, hex: '#9e2a1b' }),
+  Object.freeze({ name: 'red', minFrp: 5, hex: '#d2401f' }),
+  Object.freeze({ name: 'flame', minFrp: 20, hex: '#f06a28' }),
+  Object.freeze({ name: 'orange', minFrp: 50, hex: '#fb9a2e' }),
+  Object.freeze({ name: 'gold', minFrp: 100, hex: '#fdc84a' }),
+  Object.freeze({ name: 'white-hot', minFrp: 300, hex: '#fff3b0' }),
+]);
+
+/** Slider ticks: the ramp thresholds, so slider, legend and markers agree. */
+export const FRP_SLIDER_TICKS = Object.freeze(
+  FRP_RAMP.map((stop) => stop.minFrp),
+);
+
+/** Minimum-FRP values the share codec accepts, in whole megawatts. */
+export const MIN_FRP_MW_MIN = 0;
+export const MIN_FRP_MW_MAX = 10_000;
+
+/** Confidence switch positions; VIIRS reports only low / nominal / high. */
+export const FIRMS_CONFIDENCE_MODES = Object.freeze(['all', 'nominal', 'high']);
+
+/**
+ * Normalized-confidence floor for a switch position. The thresholds match
+ * `confidenceBucket` in the layer model (0.3 / 0.6 / 0.9 after firmsAdapt).
+ */
+const CONFIDENCE_FLOOR = Object.freeze({ all: 0, nominal: 0.45, high: 0.75 });
+
+export const DEFAULT_FIRE_FILTER = Object.freeze({
+  minFrp: 0,
+  confidence: 'all',
+});
+
+/**
+ * The ramp stop for a fire radiative power.
+ * @param {number} frp Megawatts; non-finite or negative reads as 0.
+ * @returns {{name: string, minFrp: number, hex: string}}
+ */
+export function frpRampStop(frp) {
+  const value = Number.isFinite(frp) ? Math.max(0, frp) : 0;
+  let stop = FRP_RAMP[0];
+  for (const candidate of FRP_RAMP) {
+    if (value >= candidate.minFrp) stop = candidate;
+    else break;
+  }
+  return stop;
+}
+
+/** `#rrggbb` → `[r, g, b]` in 0..255. */
+export function hexToRgb(hex) {
+  const text = String(hex).replace('#', '');
+  return [0, 2, 4].map((offset) =>
+    Number.parseInt(text.slice(offset, offset + 2), 16),
+  );
+}
+
+/**
+ * Log-scale slider axis: position 0 means "no minimum" (0 MW), and the rest
+ * of the track runs 1 MW → SLIDER_MAX_MW logarithmically. The axis floor is 1
+ * MW because the median detection is ~6 MW and a sub-megawatt floor hides
+ * nothing worth a tick.
+ */
+export const SLIDER_MAX_MW = 1000;
+const LOG_MAX = Math.log10(SLIDER_MAX_MW);
+
+/**
+ * Track position in 0..1 for a minimum FRP.
+ * @param {number} minFrp Megawatts.
+ * @returns {number}
+ */
+export function sliderPositionForFrp(minFrp) {
+  if (!Number.isFinite(minFrp) || minFrp < 1) return 0;
+  return Math.min(1, Math.log10(minFrp) / LOG_MAX);
+}
+
+/**
+ * Minimum FRP for a track position, rounded to whole megawatts so a slider
+ * value and its share-link form are the same number.
+ * @param {number} position 0..1.
+ * @returns {number}
+ */
+export function frpForSliderPosition(position) {
+  const p = Number.isFinite(position) ? Math.max(0, Math.min(1, position)) : 0;
+  if (p <= 0) return 0;
+  const frp = Math.pow(10, p * LOG_MAX);
+  return Math.max(1, Math.round(frp));
+}
+
+/**
+ * CSS `linear-gradient` painting the stepped ramp along the log axis, so the
+ * slider track IS the legend: the color under the thumb is the color of the
+ * weakest fire still shown.
+ * @returns {string}
+ */
+export function rampTrackGradient() {
+  const parts = [];
+  FRP_RAMP.forEach((stop, index) => {
+    const start = sliderPositionForFrp(stop.minFrp) * 100;
+    const next = FRP_RAMP[index + 1];
+    const end = next ? sliderPositionForFrp(next.minFrp) * 100 : 100;
+    parts.push(`${stop.hex} ${start.toFixed(2)}% ${end.toFixed(2)}%`);
+  });
+  return `linear-gradient(90deg, ${parts.join(', ')})`;
+}
+
+/**
+ * Minimum FRP → whole megawatts inside the codec bounds, or null.
+ * @param {*} value
+ * @returns {?number}
+ */
+export function normalizeMinFrp(value) {
+  const number =
+    typeof value === 'number'
+      ? value
+      : typeof value === 'string' && value.trim() !== ''
+        ? Number(value)
+        : NaN;
+  if (!Number.isFinite(number)) return null;
+  const rounded = Math.round(number);
+  return rounded >= MIN_FRP_MW_MIN && rounded <= MIN_FRP_MW_MAX
+    ? rounded
+    : null;
+}
+
+/**
+ * Confidence mode → one of FIRMS_CONFIDENCE_MODES, or null.
+ * @param {*} value
+ * @returns {?string}
+ */
+export function normalizeConfidenceMode(value) {
+  const text = String(value ?? '')
+    .trim()
+    .toLowerCase();
+  return FIRMS_CONFIDENCE_MODES.includes(text) ? text : null;
+}
+
+/**
+ * Sanitize a partial filter against the current one; unknown or invalid
+ * fields keep their current value.
+ * @param {Object} [params]
+ * @param {{minFrp: number, confidence: string}} [current]
+ * @returns {{minFrp: number, confidence: string}}
+ */
+export function normalizeFireFilter(
+  params = {},
+  current = DEFAULT_FIRE_FILTER,
+) {
+  const minFrp = normalizeMinFrp(params?.minFrp);
+  const confidence = normalizeConfidenceMode(params?.confidence);
+  return {
+    minFrp: minFrp === null ? current.minFrp : minFrp,
+    confidence: confidence === null ? current.confidence : confidence,
+  };
+}
+
+/**
+ * Whether one fire passes the filter. `confidence` is the normalized 0..1
+ * value firmsAdapt produces; `frp` is megawatts.
+ * @param {{frp: number, confidence: number}} fire
+ * @param {{minFrp: number, confidence: string}} filter
+ * @returns {boolean}
+ */
+export function firePassesFilter(fire, filter = DEFAULT_FIRE_FILTER) {
+  const frp = Number.isFinite(fire?.frp) ? fire.frp : 0;
+  if (frp < (filter.minFrp || 0)) return false;
+  const floor = CONFIDENCE_FLOOR[filter.confidence] ?? 0;
+  if (floor <= 0) return true;
+  const confidence = Number.isFinite(fire?.confidence) ? fire.confidence : 0;
+  return confidence >= floor;
+}
+
+/**
+ * The fires that pass the filter, in input order. Returns the SAME array when
+ * the filter is the default, so callers can tell "nothing hidden" cheaply.
+ * @template T
+ * @param {Array<T>} fires Internal records (normalized confidence).
+ * @param {{minFrp: number, confidence: string}} filter
+ * @returns {Array<T>}
+ */
+export function filterFires(fires, filter = DEFAULT_FIRE_FILTER) {
+  if (!Array.isArray(fires)) return [];
+  if (isDefaultFireFilter(filter)) return fires;
+  return fires.filter((fire) => firePassesFilter(fire, filter));
+}
+
+/** True when the filter hides nothing. */
+export function isDefaultFireFilter(filter) {
+  return (
+    !(filter?.minFrp > 0) &&
+    (filter?.confidence === 'all' || filter?.confidence == null)
+  );
+}
diff --git a/src/data/firmsIntensity.test.mjs b/src/data/firmsIntensity.test.mjs
new file mode 100644
index 000000000..c1d22948b
--- /dev/null
+++ b/src/data/firmsIntensity.test.mjs
@@ -0,0 +1,221 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  DEFAULT_FIRE_FILTER,
+  FIRMS_CONFIDENCE_MODES,
+  FRP_RAMP,
+  FRP_SLIDER_TICKS,
+  filterFires,
+  firePassesFilter,
+  frpForSliderPosition,
+  frpRampStop,
+  hexToRgb,
+  isDefaultFireFilter,
+  normalizeConfidenceMode,
+  normalizeFireFilter,
+  normalizeMinFrp,
+  rampTrackGradient,
+  sliderPositionForFrp,
+} from './firmsIntensity.js';
+
+test('the ramp has six ember → white-hot stops at 0 · 5 · 20 · 50 · 100 · 300 MW', () => {
+  assert.deepEqual(
+    FRP_RAMP.map((stop) => [stop.name, stop.minFrp, stop.hex]),
+    [
+      ['ember', 0, '#9e2a1b'],
+      ['red', 5, '#d2401f'],
+      ['flame', 20, '#f06a28'],
+      ['orange', 50, '#fb9a2e'],
+      ['gold', 100, '#fdc84a'],
+      ['white-hot', 300, '#fff3b0'],
+    ],
+  );
+  assert.deepEqual([...FRP_SLIDER_TICKS], [0, 5, 20, 50, 100, 300]);
+  assert.ok(Object.isFrozen(FRP_RAMP));
+});
+
+test('every stop is warm and each is lighter than the one below', () => {
+  const luma = ([r, g, b]) => 0.2126 * r + 0.7152 * g + 0.0722 * b;
+  let previous = -1;
+  for (const stop of FRP_RAMP) {
+    const rgb = hexToRgb(stop.hex);
+    assert.ok(rgb[0] >= rgb[2], `${stop.name} has no cold hue`);
+    assert.ok(
+      luma(rgb) > previous,
+      `${stop.name} is lighter than the stop below`,
+    );
+    previous = luma(rgb);
+  }
+});
+
+test('a detection takes the last stop it reaches; garbage reads as 0 MW', () => {
+  assert.equal(frpRampStop(0).name, 'ember');
+  assert.equal(frpRampStop(4.99).name, 'ember');
+  assert.equal(frpRampStop(5).name, 'red');
+  assert.equal(frpRampStop(19.9).name, 'red');
+  assert.equal(frpRampStop(20).name, 'flame');
+  assert.equal(frpRampStop(50).name, 'orange');
+  assert.equal(frpRampStop(100).name, 'gold');
+  assert.equal(frpRampStop(299.9).name, 'gold');
+  assert.equal(frpRampStop(300).name, 'white-hot');
+  assert.equal(frpRampStop(1246).name, 'white-hot');
+  assert.equal(frpRampStop(NaN).name, 'ember');
+  assert.equal(frpRampStop(-3).name, 'ember');
+  assert.equal(frpRampStop(undefined).name, 'ember');
+});
+
+test('hex stops convert to the "r, g, b" accents the cards paint', () => {
+  assert.deepEqual(hexToRgb('#9e2a1b'), [158, 42, 27]);
+  assert.deepEqual(hexToRgb('d1382a'), [209, 56, 42]);
+});
+
+test('the log slider pins 0 MW at the left and runs 1 → 1000 MW; values round-trip', () => {
+  assert.equal(sliderPositionForFrp(0), 0);
+  assert.equal(sliderPositionForFrp(0.5), 0);
+  assert.equal(sliderPositionForFrp(1), 0);
+  assert.ok(Math.abs(sliderPositionForFrp(10) - 1 / 3) < 1e-9);
+  assert.ok(Math.abs(sliderPositionForFrp(100) - 2 / 3) < 1e-9);
+  assert.equal(sliderPositionForFrp(1000), 1);
+  assert.equal(sliderPositionForFrp(5000), 1, 'clamped past the axis end');
+  assert.equal(frpForSliderPosition(0), 0);
+  assert.equal(frpForSliderPosition(1), 1000);
+  assert.equal(frpForSliderPosition(-1), 0);
+  assert.equal(frpForSliderPosition(2), 1000);
+  for (const frp of FRP_SLIDER_TICKS) {
+    assert.equal(
+      frpForSliderPosition(sliderPositionForFrp(frp)),
+      frp,
+      `tick ${frp} MW round-trips through the axis`,
+    );
+  }
+  // Ticks spread along the track instead of bunching at one end.
+  const positions = FRP_SLIDER_TICKS.map(sliderPositionForFrp);
+  for (let i = 1; i < positions.length; i += 1) {
+    assert.ok(positions[i] - positions[i - 1] >= 0.09, `tick gap ${i}`);
+  }
+});
+
+test('the track gradient is the stepped ramp on the log axis, so it doubles as the legend', () => {
+  const gradient = rampTrackGradient();
+  assert.match(gradient, /^linear-gradient\(90deg, /);
+  assert.match(gradient, /#9e2a1b 0\.00% 23\.3\d%/);
+  assert.match(gradient, /#d2401f 23\.3\d% 43\.3\d%/);
+  assert.match(gradient, /#fff3b0 82\.5\d% 100\.00%\)$/);
+  assert.equal(gradient.match(/#/g).length, FRP_RAMP.length);
+});
+
+test('minimum FRP normalizes to whole megawatts inside the codec bounds', () => {
+  assert.equal(normalizeMinFrp(0), 0);
+  assert.equal(normalizeMinFrp(19.6), 20);
+  assert.equal(normalizeMinFrp('100'), 100);
+  assert.equal(normalizeMinFrp(10000), 10000);
+  assert.equal(normalizeMinFrp(10001), null);
+  assert.equal(normalizeMinFrp(-1), null);
+  assert.equal(normalizeMinFrp('abc'), null);
+  assert.equal(normalizeMinFrp(''), null);
+  assert.equal(normalizeMinFrp(null), null);
+  assert.equal(normalizeMinFrp(NaN), null);
+});
+
+test('confidence modes are exactly all / nominal / high', () => {
+  assert.deepEqual([...FIRMS_CONFIDENCE_MODES], ['all', 'nominal', 'high']);
+  assert.equal(normalizeConfidenceMode(' High '), 'high');
+  assert.equal(normalizeConfidenceMode('nominal'), 'nominal');
+  assert.equal(normalizeConfidenceMode('low'), null);
+  assert.equal(normalizeConfidenceMode(0.9), null);
+  assert.equal(normalizeConfidenceMode(undefined), null);
+});
+
+test('a partial filter patches the current one and invalid fields keep their value', () => {
+  assert.deepEqual(normalizeFireFilter(), DEFAULT_FIRE_FILTER);
+  assert.deepEqual(normalizeFireFilter({ minFrp: 20 }), {
+    minFrp: 20,
+    confidence: 'all',
+  });
+  assert.deepEqual(
+    normalizeFireFilter(
+      { confidence: 'high' },
+      { minFrp: 50, confidence: 'all' },
+    ),
+    { minFrp: 50, confidence: 'high' },
+  );
+  assert.deepEqual(
+    normalizeFireFilter(
+      { minFrp: 'nope', confidence: 'medium' },
+      { minFrp: 50, confidence: 'nominal' },
+    ),
+    { minFrp: 50, confidence: 'nominal' },
+  );
+  assert.equal(isDefaultFireFilter(DEFAULT_FIRE_FILTER), true);
+  assert.equal(isDefaultFireFilter({ minFrp: 0, confidence: 'all' }), true);
+  assert.equal(isDefaultFireFilter({ minFrp: 1, confidence: 'all' }), false);
+  assert.equal(isDefaultFireFilter({ minFrp: 0, confidence: 'high' }), false);
+});
+
+test('the filter keeps a fire at or above the floor and at or above the confidence mode', () => {
+  const low = { frp: 864, confidence: 0.3 };
+  const nominal = { frp: 20, confidence: 0.6 };
+  const high = { frp: 2, confidence: 0.9 };
+  assert.equal(firePassesFilter(low), true, 'default shows everything');
+  assert.equal(
+    firePassesFilter(nominal, { minFrp: 20, confidence: 'all' }),
+    true,
+  );
+  assert.equal(
+    firePassesFilter(nominal, { minFrp: 21, confidence: 'all' }),
+    false,
+  );
+  assert.equal(
+    firePassesFilter(low, { minFrp: 0, confidence: 'nominal' }),
+    false,
+  );
+  assert.equal(
+    firePassesFilter(nominal, { minFrp: 0, confidence: 'nominal' }),
+    true,
+  );
+  assert.equal(
+    firePassesFilter(high, { minFrp: 0, confidence: 'nominal' }),
+    true,
+  );
+  assert.equal(
+    firePassesFilter(nominal, { minFrp: 0, confidence: 'high' }),
+    false,
+  );
+  assert.equal(firePassesFilter(high, { minFrp: 0, confidence: 'high' }), true);
+  assert.equal(
+    firePassesFilter(high, { minFrp: 5, confidence: 'high' }),
+    false,
+  );
+  // Missing numbers read as 0, never as a pass-through.
+  assert.equal(firePassesFilter({}, { minFrp: 1, confidence: 'all' }), false);
+  assert.equal(
+    firePassesFilter({ frp: 10 }, { minFrp: 0, confidence: 'nominal' }),
+    false,
+  );
+});
+
+test('filterFires returns the same array for the default filter and preserves order otherwise', () => {
+  const fires = [
+    { frp: 864, confidence: 0.3 },
+    { frp: 20, confidence: 0.6 },
+    { frp: 2, confidence: 0.9 },
+    { frp: 120, confidence: 0.9 },
+  ];
+  assert.equal(filterFires(fires), fires);
+  assert.equal(filterFires(fires, { minFrp: 0, confidence: 'all' }), fires);
+  assert.deepEqual(
+    filterFires(fires, { minFrp: 20, confidence: 'all' }).map((f) => f.frp),
+    [864, 20, 120],
+  );
+  assert.deepEqual(
+    filterFires(fires, { minFrp: 0, confidence: 'high' }).map((f) => f.frp),
+    [2, 120],
+  );
+  assert.deepEqual(
+    filterFires(fires, { minFrp: 100, confidence: 'nominal' }).map(
+      (f) => f.frp,
+    ),
+    [120],
+  );
+  assert.deepEqual(filterFires(null, { minFrp: 1, confidence: 'all' }), []);
+});
diff --git a/src/data/firmsInteraction.test.mjs b/src/data/firmsInteraction.test.mjs
index d735df3f8..8e12a435d 100644
--- a/src/data/firmsInteraction.test.mjs
+++ b/src/data/firmsInteraction.test.mjs
@@ -15,6 +15,7 @@ import { WORLD_FOCUS_REQUEST_EVENT } from '../worldFocus.js';
 import { readLayerSource } from '../testSupport/readLayerSource.mjs';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
+import { HEAT_REBUILD_MS } from '../layers/firms/policy.js';
 
 const LAYER_SOURCE = readLayerSource(
   path.join(path.dirname(fileURLToPath(import.meta.url)), 'firmsHeatmap.js'),
@@ -392,3 +393,153 @@ test('disable cancels a pending source and a late response cannot repopulate the
     assert.equal(h.layer.getStats().loading, false);
   } finally { h.layer.destroy(h.viewer); h.cleanup(); }
 });
+
+test('the heatmap is preloaded under the markers before the first zoom-out', (t) => {
+  t.mock.timers.enable({ apis: ['setTimeout'] });
+  const priorDocument = globalThis.document;
+  globalThis.document = {
+    createElement: () => ({
+      getContext: () => ({
+        createImageData: (w, hh) => ({ data: new Uint8ClampedArray(w * hh * 4) }),
+        putImageData() {},
+        createRadialGradient: () => ({ addColorStop() {} }),
+        fillRect() {},
+      }),
+      toDataURL: () => 'data:image/png;base64,AAAA',
+    }),
+  };
+  const h = harness({
+    withDataSource: true,
+    cameraPosition: Cesium.Cartesian3.fromDegrees(-98, 30, 1_000_000),
+  });
+  h.viewer.camera = { positionCartographic: { height: 1_000_000 } };
+  h.viewer.scene.primitives = { add() {}, remove() {}, raiseToTop() {}, contains: () => true };
+  h.viewer.scene.frameState = { mode: Cesium.SceneMode.SCENE3D };
+  const added = [];
+  try {
+    h.layer.attachShellServices({
+      imageryHost: () => ({
+        kind: 'globe',
+        collection: {
+          addImageryProvider: (provider) => {
+            const layer = { provider, show: true, alpha: 1 };
+            added.push(layer);
+            return layer;
+          },
+          remove() {},
+          raiseToTop() {},
+        },
+      }),
+    });
+    h.layer._renderLodForTest('close');
+    assert.equal(added.length, 0, 'the markers paint first; the build trails');
+    t.mock.timers.tick(HEAT_REBUILD_MS);
+    assert.equal(added.length, 1, 'then the heatmap is draped');
+    assert.equal(added[0].alpha, 0, 'invisible until the hand-off');
+    assert.equal(added[0].show, true, 'but mapped onto the globe tiles');
+  } finally {
+    h.layer.destroy(h.viewer);
+    h.cleanup();
+    if (priorDocument === undefined) delete globalThis.document;
+    else globalThis.document = priorDocument;
+  }
+});
+
+test('far zoom drapes one heatmap and the hand-off cross-fades it with the markers', () => {
+  // A canvas stub for the heat drape and the detection glow sprites.
+  const priorDocument = globalThis.document;
+  const restoreDocument = () => {
+    if (priorDocument === undefined) delete globalThis.document;
+    else globalThis.document = priorDocument;
+  };
+  globalThis.document = {
+    createElement: () => ({
+      getContext: () => ({
+        createImageData: (w, hh) => ({
+          data: new Uint8ClampedArray(w * hh * 4),
+        }),
+        putImageData() {},
+        createRadialGradient: () => ({ addColorStop() {} }),
+        fillRect() {},
+      }),
+      toDataURL: () => 'data:image/png;base64,AAAA',
+    }),
+  };
+  const h = harness({
+    fires: [makeFire(), makeFire({ index: 8, lat: 30.6, lon: -98.3, frp: 12 })],
+    withDataSource: true,
+    cameraPosition: Cesium.Cartesian3.fromDegrees(-98, 30, 12_000_000),
+  });
+  const added = [];
+  const removed = [];
+  let markers = null;
+  // The fade reads the camera height; the cull reads scene.camera.
+  const setHeight = (height) => {
+    h.viewer.camera = { positionCartographic: { height } };
+  };
+  setHeight(12_000_000);
+  h.viewer.scene.primitives = {
+    add(primitive) {
+      markers = primitive;
+    },
+    remove() {},
+    raiseToTop() {},
+    contains: () => true,
+  };
+  h.viewer.scene.frameState = { mode: Cesium.SceneMode.SCENE3D };
+  try {
+    const collection = {
+      addImageryProvider: (provider) => {
+        const layer = { provider, show: true, alpha: 1 };
+        added.push(layer);
+        return layer;
+      },
+      remove: (layer, destroy) => removed.push({ layer, destroy }),
+      raiseToTop() {},
+    };
+    h.layer.attachShellServices({
+      imageryHost: () => ({ kind: 'globe', collection }),
+    });
+    h.layer._renderLodForTest('global');
+    assert.equal(added.length, 1, 'one heat imagery layer');
+    assert.equal(added[0].show, true);
+    assert.equal(added[0].alpha, 1);
+    assert.equal(h.layer._entityCountForTest(), 0, 'no rectangle entities');
+    assert.ok(h.published.length > 0, 'the far band still paints cards');
+    assert.equal(markers.length, 2, 'the markers are built under the heatmap');
+    assert.equal(markers.show, false, 'and hidden while the heatmap is whole');
+
+    h.layer._renderLodForTest('regional');
+    assert.equal(added.length, 1, 'switching far bands reuses the raster');
+
+    setHeight(1_000_000);
+    h.layer._renderLodForTest('close');
+    assert.equal(added.length, 1, 'the markers band keeps the same heat layer');
+    assert.equal(added[0].show, true, 'still mapped onto the globe tiles');
+    assert.equal(added[0].alpha, 0, 'faded out under the markers');
+    assert.equal(markers.show, true);
+    assert.equal(markers.get(0).color.alpha, 1);
+
+    // Mid hand-off both are drawn, half each, in either band.
+    setHeight(4_500_000);
+    h.layer._applyHandoffFadeForTest();
+    assert.equal(added[0].alpha, 0.5);
+    assert.equal(markers.show, true);
+    assert.equal(markers.get(0).color.alpha, 0.5);
+    h.layer._renderLodForTest('regional');
+    assert.equal(added[0].alpha, 0.5);
+    assert.equal(markers.get(1).color.alpha, 0.5, 'rebuilt markers get the fade');
+
+    h.layer.disable();
+    assert.equal(added[0].show, false, 'disable hides the heatmap');
+
+    h.layer.destroy(h.viewer);
+    assert.deepEqual(
+      removed.map((entry) => [entry.layer, entry.destroy]),
+      [[added[0], true]],
+    );
+  } finally {
+    h.cleanup();
+    restoreDocument();
+  }
+});
diff --git a/src/data/firmsLabels.js b/src/data/firmsLabels.js
index b9e9d1765..bf97982c2 100644
--- a/src/data/firmsLabels.js
+++ b/src/data/firmsLabels.js
@@ -4,6 +4,8 @@
  * dedicated card canvas moved into the shared world-overlay host.
  */
 
+import { FRP_RAMP, hexToRgb } from './firmsIntensity.js';
+
 /** Shipped ambient FIRMS card ceiling. Selected fires bypass this cohort. */
 export const FIRMS_AMBIENT_COHORT_LIMIT = 18;
 export const FIRMS_OVERLAY_SOURCE_ID = 'firms';
@@ -23,20 +25,23 @@ export function fireDetectionKey(fire) {
   return `firms:${lat}:${lon}:${acq}:${source}`;
 }
 
-/** Severity accent palette — matches the FIRMS glow-sprite color stops. */
-const ACCENT_RGB = Object.freeze({
-  red: '224, 82, 82',
-  orange: '240, 178, 62',
-  yellow: '244, 227, 108',
-});
+/**
+ * Severity accent palette — the FIRMS glow-sprite color stops (the six-stop
+ * FRP ramp in firmsIntensity.js) as "r, g, b" strings for card accents.
+ */
+const ACCENT_RGB = Object.freeze(
+  Object.fromEntries(
+    FRP_RAMP.map((stop) => [stop.name, hexToRgb(stop.hex).join(', ')]),
+  ),
+);
 
 /**
- * Severity stop name → "r, g, b" accent string (defaults to yellow).
- * @param {string} stopName - 'red' | 'orange' | 'yellow'.
+ * Severity stop name → "r, g, b" accent string (defaults to the weakest stop).
+ * @param {string} stopName - A FRP_RAMP stop name ('ember' … 'white-hot').
  * @returns {string}
  */
 export function accentForSeverity(stopName) {
-  return ACCENT_RGB[stopName] || ACCENT_RGB.yellow;
+  return ACCENT_RGB[stopName] || ACCENT_RGB[FRP_RAMP[0].name];
 }
 
 /**
diff --git a/src/data/firmsLabels.test.mjs b/src/data/firmsLabels.test.mjs
index 8573d7330..a141d0d17 100644
--- a/src/data/firmsLabels.test.mjs
+++ b/src/data/firmsLabels.test.mjs
@@ -9,11 +9,16 @@ import {
   formatFrpMw,
 } from './firmsLabels.js';
 
-test('FIRMS formatting helpers retain the shipped severity palette', () => {
-  assert.equal(accentForSeverity('red'), '224, 82, 82');
-  assert.equal(accentForSeverity('orange'), '240, 178, 62');
-  assert.equal(accentForSeverity('yellow'), '244, 227, 108');
-  assert.equal(accentForSeverity('chartreuse'), accentForSeverity('yellow'));
+test('FIRMS card accents are the six FRP ramp stops, weakest as the fallback', () => {
+  // Ember #9e2a1b … white-hot #fff3b0, lightness rising with power.
+  assert.equal(accentForSeverity('ember'), '158, 42, 27');
+  assert.equal(accentForSeverity('red'), '210, 64, 31');
+  assert.equal(accentForSeverity('flame'), '240, 106, 40');
+  assert.equal(accentForSeverity('orange'), '251, 154, 46');
+  assert.equal(accentForSeverity('gold'), '253, 200, 74');
+  assert.equal(accentForSeverity('white-hot'), '255, 243, 176');
+  assert.equal(accentForSeverity('blue'), accentForSeverity('ember'));
+  assert.equal(accentForSeverity('chartreuse'), accentForSeverity('ember'));
 });
 
 test('FIRMS power that rounds to 10 MW drops the decimal', () => {
diff --git a/src/data/layerState.js b/src/data/layerState.js
index 968c53520..46dadf9a0 100644
--- a/src/data/layerState.js
+++ b/src/data/layerState.js
@@ -298,6 +298,20 @@ function satelliteFilterOption() {
 }
 
 const OPTION_GROUPS = Object.freeze({
+  // Active Fires intensity filter (HAL-676). `minFrp` is whole megawatts on
+  // the codec side; the panel's log slider rounds to it. Both default to
+  // "show everything": many of the strongest fires are rated low confidence.
+  // The bounds and modes mirror MIN_FRP_MW_MAX / FIRMS_CONFIDENCE_MODES in
+  // firmsIntensity.js (pinned by layerState.test); spelled out here because
+  // this file runs in isolation in the token-ledger tests.
+  'local-firms': Object.freeze([
+    boundedIntegerOption('minFrp', 'f', 0, { min: 0, max: 10000 }),
+    enumOption('confidence', 'c', 'all', ['all', 'nominal', 'high'], {
+      all: 'a',
+      nominal: 'n',
+      high: 'h',
+    }),
+  ]),
   traffic: Object.freeze([
     enumOption('roadMode', 'r', null, ['tomtom', 'osm', 'hybrid'], {
       tomtom: 't',
@@ -626,7 +640,12 @@ export const LAYER_STATE_REGISTRY = Object.freeze([
     token: 'd',
     disposition: 'enabled-only',
   }),
-  Object.freeze({ id: 'local-firms', token: 'w', disposition: 'enabled-only' }),
+  Object.freeze({
+    id: 'local-firms',
+    token: 'w',
+    disposition: 'enabled+options',
+    optionOwner: 'local-firms',
+  }),
   Object.freeze({
     id: 'military',
     token: 'm',
diff --git a/src/data/layerState.test.mjs b/src/data/layerState.test.mjs
index 9d9bb29b5..9d30e8973 100644
--- a/src/data/layerState.test.mjs
+++ b/src/data/layerState.test.mjs
@@ -29,6 +29,7 @@ import radioLayer from './radio.js';
 import { stampInitialShareGesture } from '../navigationPolicy.js';
 import { MAX_SINCE_DAYS } from '../layers/streetLevel/policy.js';
 import { SINCE_STOPS } from '../ui/streetLevelPresentation.js';
+import { FIRMS_CONFIDENCE_MODES, MIN_FRP_MW_MAX } from './firmsIntensity.js';
 
 function deferred() {
   let resolve;
@@ -3007,9 +3008,89 @@ test('Clear All cancels a saved restore still waiting to start', async () => {
   gate.resolve();
   const results = await restore;
   for (const id of ['earthquakes', 'flights']) {
-    assert.equal(results.find((result) => result.layerId === id).succeeded, false);
+    assert.equal(
+      results.find((result) => result.layerId === id).succeeded,
+      false,
+    );
   }
   assert.deepEqual([...manager.getEnabledLayerIds()], []);
   assert.equal(enabledLayerParam(sink), '');
   coordinator.destroy();
 });
+
+/** Active Fires options decoded from a v2 link with these `lo` assignments. */
+function firmsOptions(lo) {
+  const params = new URLSearchParams([
+    ['v', '2'],
+    ['l', 'w'],
+  ]);
+  if (lo) params.set('lo', lo);
+  return decodeLayerStateParams(params).options['local-firms'];
+}
+
+test('Active Fires: the intensity filter rides share token w and round-trips', () => {
+  const state = createDefaultLayerState();
+  assert.deepEqual(state.options['local-firms'], {
+    minFrp: 0,
+    confidence: 'all',
+  });
+  state.enabledLayerIds = ['local-firms'];
+  state.options['local-firms'] = { minFrp: 20, confidence: 'high' };
+  const encoded = encode(state);
+  assert.equal(new URLSearchParams(encoded).get('l'), 'w');
+  // Other owners write their own explicit defaults into `lo` too (flights 3D,
+  // wind overlay); the fire assignments ride beside them.
+  const assignments = new URLSearchParams(encoded).get('lo').split('_');
+  assert.ok(assignments.includes('w.f.20'), assignments.join(' '));
+  assert.ok(assignments.includes('w.c.h'), assignments.join(' '));
+  const decoded = decodeLayerStateParams(new URLSearchParams(encoded));
+  assert.deepEqual(decoded.options['local-firms'], {
+    minFrp: 20,
+    confidence: 'high',
+  });
+  assert.deepEqual(
+    parseStoredLayerState(serializeStoredLayerState(state)).options[
+      'local-firms'
+    ],
+    state.options['local-firms'],
+  );
+  // Defaults are omitted from the link: a plain `l=w` is "show everything".
+  const plain = createDefaultLayerState();
+  plain.enabledLayerIds = ['local-firms'];
+  assert.equal(
+    new URLSearchParams(encode(plain))
+      .get('lo')
+      .split('_')
+      .filter((assignment) => assignment.startsWith('w.')).length,
+    0,
+  );
+  assert.deepEqual(firmsOptions(''), { minFrp: 0, confidence: 'all' });
+});
+
+test('Active Fires: the codec accepts whole megawatts in bounds and the three confidence codes', () => {
+  // The codec spells its bounds out (it runs in isolation in the ledger
+  // tests); they must stay the layer's.
+  assert.equal(MIN_FRP_MW_MAX, 10000);
+  assert.deepEqual([...FIRMS_CONFIDENCE_MODES], ['all', 'nominal', 'high']);
+  assert.equal(firmsOptions('w.f.300').minFrp, 300);
+  assert.equal(firmsOptions('w.f.10000').minFrp, 10000);
+  assert.equal(firmsOptions('w.f.10001').minFrp, 0, 'out of bounds → default');
+  assert.equal(firmsOptions('w.f.-5').minFrp, 0);
+  assert.equal(
+    firmsOptions('w.f.2.5').minFrp,
+    0,
+    'a third segment is rejected',
+  );
+  assert.equal(firmsOptions('w.c.a').confidence, 'all');
+  assert.equal(firmsOptions('w.c.n').confidence, 'nominal');
+  assert.equal(firmsOptions('w.c.h').confidence, 'high');
+  assert.equal(
+    firmsOptions('w.c.x').confidence,
+    'all',
+    'unknown code → default',
+  );
+  assert.deepEqual(firmsOptions('w.c.n_w.f.5'), {
+    minFrp: 5,
+    confidence: 'nominal',
+  });
+});
diff --git a/src/i18n/locales/ar.json b/src/i18n/locales/ar.json
index 629bcacab..c9fca14ce 100644
--- a/src/i18n/locales/ar.json
+++ b/src/i18n/locales/ar.json
@@ -3214,6 +3214,19 @@
   "Download the timing log of the last play": "تنزيل سجل توقيت آخر تشغيل",
   "Edit anchors, data packs and shot details": "تعديل نقاط الارتكاز وحزم البيانات وتفاصيل اللقطة",
   "Download this scene as JSON or an asset bundle": "تنزيل هذا المشهد بصيغة JSON أو حزمة موارد",
+  "fire confidence filter|All": "الكل",
+  "fire confidence filter|Nominal+": "متوسطة فأعلى",
+  "fire confidence filter|High": "عالية",
+  "Every detection — many of the strongest fires are rated low confidence": "كل عمليات الرصد — كثير من أقوى الحرائق مصنّفة بثقة منخفضة",
+  "Nominal and high confidence detections": "عمليات الرصد ذات الثقة المتوسطة والعالية",
+  "High confidence detections only": "عمليات الرصد ذات الثقة العالية فقط",
+  "Fire intensity (FRP)": "الشدة (FRP)",
+  "≥ {value} MW": "{value} MW على الأقل",
+  "Confidence": "الثقة",
+  "Minimum fire radiative power, megawatts": "الحد الأدنى للقدرة الإشعاعية للحريق، بالميغاواط",
+  "fire intensity filter|All": "الكل",
+  "Detection confidence": "ثقة الرصد",
+  "{shown} of {total} shown": "المعروضة: {shown} من {total}",
   "Name of {name}": "اسم {name}",
   "Change the colour of {name}": "تغيير لون {name}",
   "Colour of {name}": "لون {name}",
diff --git a/src/i18n/locales/de.json b/src/i18n/locales/de.json
index e795801fd..bb683ed9f 100644
--- a/src/i18n/locales/de.json
+++ b/src/i18n/locales/de.json
@@ -2946,6 +2946,19 @@
   "Right panels": "Rechte Panels",
   "CONFIRMED": "BESTÄTIGT",
   "PAD / RTLS": "STARTPLATZ / RTLS",
+  "fire confidence filter|All": "Alle",
+  "fire confidence filter|Nominal+": "Mittel+",
+  "fire confidence filter|High": "Hoch",
+  "Every detection — many of the strongest fires are rated low confidence": "Alle Erkennungen — viele der stärksten Brände haben eine niedrige Konfidenz",
+  "Nominal and high confidence detections": "Erkennungen mit mittlerer und hoher Konfidenz",
+  "High confidence detections only": "Nur Erkennungen mit hoher Konfidenz",
+  "Fire intensity (FRP)": "Intensität (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "Konfidenz",
+  "Minimum fire radiative power, megawatts": "Minimale Strahlungsleistung des Brandes in Megawatt",
+  "fire intensity filter|All": "Alle",
+  "Detection confidence": "Konfidenz der Erkennung",
+  "{shown} of {total} shown": "{shown} von {total} angezeigt",
   "Name of {name}": "Name von {name}",
   "Change the colour of {name}": "Farbe von {name} ändern",
   "Colour of {name}": "Farbe von {name}",
diff --git a/src/i18n/locales/es.json b/src/i18n/locales/es.json
index 0dfc4dea3..10dcbef8f 100644
--- a/src/i18n/locales/es.json
+++ b/src/i18n/locales/es.json
@@ -2983,6 +2983,19 @@
   "Voice replies appear here.": "Las respuestas de voz aparecen aquí.",
   "Preview is off.": "La vista previa está desactivada.",
   "Automatic stop is unavailable for this voice connection.": "La parada automática no está disponible para esta conexión de voz.",
+  "fire confidence filter|All": "Todas",
+  "fire confidence filter|Nominal+": "Nominal+",
+  "fire confidence filter|High": "Alta",
+  "Every detection — many of the strongest fires are rated low confidence": "Todas las detecciones — muchos de los incendios más intensos tienen confianza baja",
+  "Nominal and high confidence detections": "Detecciones de confianza nominal y alta",
+  "High confidence detections only": "Solo detecciones de confianza alta",
+  "Fire intensity (FRP)": "Intensidad (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "Confianza",
+  "Minimum fire radiative power, megawatts": "Potencia radiativa mínima del fuego, en megavatios",
+  "fire intensity filter|All": "Todo",
+  "Detection confidence": "Confianza de la detección",
+  "{shown} of {total} shown": "{shown} de {total} mostrados",
   "{lower} to {upper}": "{lower} a {upper}",
   "Up to {upper}": "Hasta {upper}",
   "From {lower}": "Desde {lower}",
diff --git a/src/i18n/locales/fr.json b/src/i18n/locales/fr.json
index 27c0453c4..108e56f36 100644
--- a/src/i18n/locales/fr.json
+++ b/src/i18n/locales/fr.json
@@ -3016,6 +3016,19 @@
   "Right panels": "Panneaux de droite",
   "CONFIRMED": "CONFIRMÉE",
   "PAD / RTLS": "PAS DE TIR / RTLS",
+  "fire confidence filter|All": "Toutes",
+  "fire confidence filter|Nominal+": "Nominale+",
+  "fire confidence filter|High": "Élevée",
+  "Every detection — many of the strongest fires are rated low confidence": "Toutes les détections — beaucoup des feux les plus intenses ont une confiance faible",
+  "Nominal and high confidence detections": "Détections de confiance nominale et élevée",
+  "High confidence detections only": "Détections de confiance élevée uniquement",
+  "Fire intensity (FRP)": "Intensité (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "Confiance",
+  "Minimum fire radiative power, megawatts": "Puissance radiative minimale du feu, en mégawatts",
+  "fire intensity filter|All": "Toutes",
+  "Detection confidence": "Confiance de la détection",
+  "{shown} of {total} shown": "{shown} sur {total} affichées",
   "Name of {name}": "Nom de {name}",
   "Change the colour of {name}": "Changer la couleur de {name}",
   "Colour of {name}": "Couleur de {name}",
diff --git a/src/i18n/locales/it.json b/src/i18n/locales/it.json
index a089ba758..6768f93c7 100644
--- a/src/i18n/locales/it.json
+++ b/src/i18n/locales/it.json
@@ -3016,6 +3016,19 @@
   "Right panels": "Pannelli a destra",
   "CONFIRMED": "CONFERMATA",
   "PAD / RTLS": "SITO DI LANCIO / RTLS",
+  "fire confidence filter|All": "Tutti",
+  "fire confidence filter|Nominal+": "Nominale+",
+  "fire confidence filter|High": "Alta",
+  "Every detection — many of the strongest fires are rated low confidence": "Tutti i rilevamenti — molti degli incendi più intensi hanno confidenza bassa",
+  "Nominal and high confidence detections": "Rilevamenti con confidenza nominale e alta",
+  "High confidence detections only": "Solo rilevamenti con confidenza alta",
+  "Fire intensity (FRP)": "Intensità (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "Confidenza",
+  "Minimum fire radiative power, megawatts": "Potenza radiativa minima dell'incendio, in megawatt",
+  "fire intensity filter|All": "Tutti",
+  "Detection confidence": "Confidenza del rilevamento",
+  "{shown} of {total} shown": "{shown} di {total} mostrati",
   "Name of {name}": "Nome di {name}",
   "Change the colour of {name}": "Cambia il colore di {name}",
   "Colour of {name}": "Colore di {name}",
diff --git a/src/i18n/locales/ja.json b/src/i18n/locales/ja.json
index 1536306f1..b4566b4cb 100644
--- a/src/i18n/locales/ja.json
+++ b/src/i18n/locales/ja.json
@@ -2876,6 +2876,19 @@
   "Right panels": "右パネル",
   "CONFIRMED": "確認済み",
   "PAD / RTLS": "射場 / RTLS",
+  "fire confidence filter|All": "すべて",
+  "fire confidence filter|Nominal+": "中以上",
+  "fire confidence filter|High": "高",
+  "Every detection — many of the strongest fires are rated low confidence": "すべての検知 — 最も強い火災の多くは信頼度が低と判定されています",
+  "Nominal and high confidence detections": "信頼度が中・高の検知",
+  "High confidence detections only": "信頼度が高の検知のみ",
+  "Fire intensity (FRP)": "強度（FRP）",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "信頼度",
+  "Minimum fire radiative power, megawatts": "火災放射強度の最小値（メガワット）",
+  "fire intensity filter|All": "すべて",
+  "Detection confidence": "検知の信頼度",
+  "{shown} of {total} shown": "{total}件中{shown}件を表示",
   "Name of {name}": "{name}の名前",
   "Change the colour of {name}": "{name}の色を変更",
   "Colour of {name}": "{name}の色",
diff --git a/src/i18n/locales/pt.json b/src/i18n/locales/pt.json
index aa57b24a4..3f37cde2e 100644
--- a/src/i18n/locales/pt.json
+++ b/src/i18n/locales/pt.json
@@ -3016,6 +3016,19 @@
   "Right panels": "Painéis à direita",
   "CONFIRMED": "CONFIRMADA",
   "PAD / RTLS": "PLATAFORMA / RTLS",
+  "fire confidence filter|All": "Todas",
+  "fire confidence filter|Nominal+": "Nominal+",
+  "fire confidence filter|High": "Alta",
+  "Every detection — many of the strongest fires are rated low confidence": "Todas as detecções — muitos dos incêndios mais intensos têm confiança baixa",
+  "Nominal and high confidence detections": "Detecções de confiança nominal e alta",
+  "High confidence detections only": "Somente detecções de confiança alta",
+  "Fire intensity (FRP)": "Intensidade (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "Confiança",
+  "Minimum fire radiative power, megawatts": "Potência radiativa mínima do fogo, em megawatts",
+  "fire intensity filter|All": "Todas",
+  "Detection confidence": "Confiança da detecção",
+  "{shown} of {total} shown": "{shown} de {total} exibidas",
   "Name of {name}": "Nome de {name}",
   "Change the colour of {name}": "Mudar a cor de {name}",
   "Colour of {name}": "Cor de {name}",
diff --git a/src/i18n/locales/ru.json b/src/i18n/locales/ru.json
index df4e575d3..e279508ef 100644
--- a/src/i18n/locales/ru.json
+++ b/src/i18n/locales/ru.json
@@ -3053,6 +3053,19 @@
   "Voice replies appear here.": "Здесь появляются голосовые ответы.",
   "Preview is off.": "Предпросмотр отключён.",
   "Automatic stop is unavailable for this voice connection.": "Автоматическая остановка недоступна для этого голосового подключения.",
+  "fire confidence filter|All": "Все",
+  "fire confidence filter|Nominal+": "Средняя+",
+  "fire confidence filter|High": "Высокая",
+  "Every detection — many of the strongest fires are rated low confidence": "Все детекции — у многих сильнейших пожаров достоверность низкая",
+  "Nominal and high confidence detections": "Детекции средней и высокой достоверности",
+  "High confidence detections only": "Только детекции высокой достоверности",
+  "Fire intensity (FRP)": "Интенсивность (FRP)",
+  "≥ {value} MW": "≥ {value} МВт",
+  "Confidence": "Достоверность",
+  "Minimum fire radiative power, megawatts": "Минимальная мощность излучения пожара, мегаватты",
+  "fire intensity filter|All": "Все",
+  "Detection confidence": "Достоверность детекции",
+  "{shown} of {total} shown": "показано {shown} из {total}",
   "{lower} to {upper}": "от {lower} до {upper}",
   "Up to {upper}": "До {upper}",
   "From {lower}": "От {lower}",
diff --git a/src/i18n/locales/uk.json b/src/i18n/locales/uk.json
index 70d4accf9..8c3b634b9 100644
--- a/src/i18n/locales/uk.json
+++ b/src/i18n/locales/uk.json
@@ -3045,6 +3045,19 @@
   "Don't show this again": "Більше не показувати",
   "ESC to dismiss": "ESC — приховати",
   "Tip: the GEV MIC button in the dock lets you talk to the map.": "Порада: кнопка МІК у доку дає змогу говорити з картою.",
+  "fire confidence filter|All": "Усі",
+  "fire confidence filter|Nominal+": "Середня+",
+  "fire confidence filter|High": "Висока",
+  "Every detection — many of the strongest fires are rated low confidence": "Усі виявлення — багато найсильніших пожеж мають низьку достовірність",
+  "Nominal and high confidence detections": "Виявлення середньої та високої достовірності",
+  "High confidence detections only": "Лише виявлення високої достовірності",
+  "Fire intensity (FRP)": "Інтенсивність (FRP)",
+  "≥ {value} MW": "≥ {value} МВт",
+  "Confidence": "Достовірність",
+  "Minimum fire radiative power, megawatts": "Мінімальна потужність випромінювання пожежі, мегавати",
+  "fire intensity filter|All": "Усі",
+  "Detection confidence": "Достовірність виявлення",
+  "{shown} of {total} shown": "показано {shown} з {total}",
   "{lower} to {upper}": "від {lower} до {upper}",
   "Up to {upper}": "До {upper}",
   "From {lower}": "Від {lower}",
diff --git a/src/i18n/locales/zh-CN.json b/src/i18n/locales/zh-CN.json
index f583c201a..6125315f2 100644
--- a/src/i18n/locales/zh-CN.json
+++ b/src/i18n/locales/zh-CN.json
@@ -2843,6 +2843,19 @@
     "other": "{count} 个地标"
   },
   "S2 Underground publishes these KMZ products to GitHub. New uploads are detected within seconds and replace the previous edition automatically. Click a marker for its report.": "S2 Underground 在 GitHub 发布这些 KMZ 产品。新上传的内容会在数秒内被检测到，并自动替换旧版本。点击标记查看报告。",
+  "fire confidence filter|All": "全部",
+  "fire confidence filter|Nominal+": "标称+",
+  "fire confidence filter|High": "高",
+  "Every detection — many of the strongest fires are rated low confidence": "所有检测——许多最强的火点置信度为低",
+  "Nominal and high confidence detections": "标称和高置信度的检测",
+  "High confidence detections only": "仅高置信度的检测",
+  "Fire intensity (FRP)": "火势强度 (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "置信度",
+  "Minimum fire radiative power, megawatts": "最小火辐射功率（兆瓦）",
+  "fire intensity filter|All": "全部",
+  "Detection confidence": "检测置信度",
+  "{shown} of {total} shown": "显示 {shown} / {total}",
   "{lower} to {upper}": "{lower} 至 {upper}",
   "Up to {upper}": "最高 {upper}",
   "From {lower}": "自 {lower} 起",
diff --git a/src/i18n/locales/zh-Hant.json b/src/i18n/locales/zh-Hant.json
index 77045451d..66eb37b96 100644
--- a/src/i18n/locales/zh-Hant.json
+++ b/src/i18n/locales/zh-Hant.json
@@ -2882,6 +2882,19 @@
   "Download this scene as JSON or an asset bundle": "將此場景下載為 JSON 或資源包",
   "Left panels": "左側面板",
   "Right panels": "右側面板",
+  "fire confidence filter|All": "全部",
+  "fire confidence filter|Nominal+": "標稱+",
+  "fire confidence filter|High": "高",
+  "Every detection — many of the strongest fires are rated low confidence": "所有檢測——許多最強的火點置信度為低",
+  "Nominal and high confidence detections": "標稱和高置信度的檢測",
+  "High confidence detections only": "僅高置信度的檢測",
+  "Fire intensity (FRP)": "火勢強度 (FRP)",
+  "≥ {value} MW": "≥ {value} MW",
+  "Confidence": "置信度",
+  "Minimum fire radiative power, megawatts": "最小火輻射功率（兆瓦）",
+  "fire intensity filter|All": "全部",
+  "Detection confidence": "檢測置信度",
+  "{shown} of {total} shown": "顯示 {shown} / {total}",
   "UTILITIES": "工具",
   "Exit cockpit to fly to a drawing": "請先退出座艙，再飛往繪製位置",
   "Directions, drawing and your own files": "路線導航、繪製和你自己的文件",
diff --git a/src/i18n/same-as-english.json b/src/i18n/same-as-english.json
index 51cd4edec..7edaad647 100644
--- a/src/i18n/same-as-english.json
+++ b/src/i18n/same-as-english.json
@@ -201,6 +201,7 @@
     "{value} KM/S",
     "ΔN",
     "Ⅱ PAUSE",
+    "≥ {value} MW",
     "▲ {frp} MW"
   ],
   "es": [
@@ -307,6 +308,7 @@
     "WX",
     "audio {state}",
     "dB",
+    "fire confidence filter|Nominal+",
     "fire confidence|nominal",
     "ft",
     "hPa",
@@ -329,6 +331,7 @@
     "{value} KM",
     "{value} KM/H",
     "{value} KM/S",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"
@@ -515,6 +518,7 @@
     "ΔE",
     "ΔN",
     "Ⅱ PAUSE",
+    "≥ {value} MW",
     "▲ {frp} MW"
   ],
   "it": [
@@ -687,6 +691,7 @@
     "{value} KM/H",
     "{value} KM/S",
     "{value} conf",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"
@@ -738,6 +743,7 @@
     "{type}  SPD: {speed}  HDG: {heading}",
     "ΔE",
     "ΔN",
+    "≥ {value} MW",
     "▲ {frp} MW"
   ],
   "pt": [
@@ -851,6 +857,7 @@
     "WHOT/BHOT",
     "WX",
     "dB",
+    "fire confidence filter|Nominal+",
     "fire confidence|nominal",
     "ft",
     "hPa",
@@ -869,7 +876,8 @@
     "{value} KM/H",
     "{value} KM/S",
     "ΔN",
-    "▲ {frp} MW"
+    "▲ {frp} MW",
+    "≥ {value} MW"
   ],
   "ru": [
     "AIS: --",
@@ -928,9 +936,9 @@
     "MM",
     "NVG",
     "REC",
-    "SRC {value}",
     "S2 GhostMaps",
     "S2 · {name}",
+    "SRC {value}",
     "Sentinel-2",
     "Techno",
     "Trance",
@@ -955,6 +963,7 @@
     "{type}  SPD: {speed}  HDG: {heading}",
     "{value} KM",
     "{value} KM/S",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"
@@ -1012,6 +1021,7 @@
     "{type}  SPD: {speed}  HDG: {heading}",
     "{value} KM",
     "{value} KM/S",
+    "≥ {value} MW",
     "ΔE",
     "ΔN",
     "▲ {frp} MW"
diff --git a/src/layers/firms/heatImagery.js b/src/layers/firms/heatImagery.js
new file mode 100644
index 000000000..710a87f43
--- /dev/null
+++ b/src/layers/firms/heatImagery.js
@@ -0,0 +1,88 @@
+/**
+ * Drapes the Active Fires heat raster over the globe as one full-extent
+ * imagery tile on the active imagery host (globe or 3D-tiles), like the wind
+ * layer's scalar field. Owns the canvas and the imagery layer; nothing else
+ * in the fires layer touches imagery.
+ *
+ * `show` is only for the layer being on or off. The zoom hand-off fades
+ * `alpha` instead: Cesium unmaps a hidden imagery layer from the globe
+ * tiles and re-maps it when shown, so a show toggle at the band edge left
+ * a beat with neither markers nor heat. At alpha 0 the layer stays mapped
+ * and costs no draw.
+ */
+
+const defaultCanvas = (width, height) => {
+  const canvas = document.createElement('canvas');
+  canvas.width = width;
+  canvas.height = height;
+  return canvas;
+};
+
+export function createHeatImagery({
+  cesium,
+  getHost,
+  createCanvas = defaultCanvas,
+}) {
+  let raster = null;
+  let layer = null;
+  let collection = null;
+  let show = true;
+  let opacity = 1;
+
+  function detach() {
+    if (layer && collection) collection.remove(layer, true);
+    layer = null;
+    collection = null;
+  }
+
+  function attach() {
+    detach();
+    if (!raster) return;
+    const host = getHost?.() ?? { collection: null, kind: 'none' };
+    if (!host.collection) return;
+    const canvas = createCanvas(raster.width, raster.height);
+    const ctx = canvas.getContext('2d');
+    const image = ctx.createImageData(raster.width, raster.height);
+    image.data.set(raster.rgba);
+    ctx.putImageData(image, 0, 0);
+    const provider = new cesium.SingleTileImageryProvider({
+      url: canvas.toDataURL('image/png'),
+      tileWidth: raster.width,
+      tileHeight: raster.height,
+      rectangle: cesium.Rectangle.MAX_VALUE,
+    });
+    collection = host.collection;
+    layer = collection.addImageryProvider(provider);
+    layer.show = show;
+    layer.alpha = opacity;
+    collection.raiseToTop?.(layer);
+  }
+
+  return {
+    setRaster(next) {
+      raster = next;
+      attach();
+    },
+    /** True once a raster was handed over (painted or waiting for a host). */
+    hasRaster() {
+      return raster !== null;
+    },
+    setShow(value) {
+      show = Boolean(value);
+      if (layer) layer.show = show;
+    },
+    /** Hand-off fade, 0..1; the layer stays mapped at 0. */
+    setOpacity(value) {
+      opacity = Math.min(1, Math.max(0, Number(value) || 0));
+      if (layer) layer.alpha = opacity;
+    },
+    rehome() {
+      const host = getHost?.();
+      if ((host?.collection ?? null) !== collection) attach();
+    },
+    destroy() {
+      detach();
+      raster = null;
+    },
+  };
+}
diff --git a/src/layers/firms/heatImagery.test.mjs b/src/layers/firms/heatImagery.test.mjs
new file mode 100644
index 000000000..27f45f55f
--- /dev/null
+++ b/src/layers/firms/heatImagery.test.mjs
@@ -0,0 +1,128 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createHeatImagery } from './heatImagery.js';
+import { buildHeatRaster } from '../../data/firmsHeatRaster.js';
+import { HEAT_RASTER } from './policy.js';
+
+function harness() {
+  const layers = [];
+  const removed = [];
+  const collection = {
+    addImageryProvider(provider) {
+      const layer = { provider, show: true, alpha: 1 };
+      layers.push(layer);
+      return layer;
+    },
+    remove(layer, destroy) {
+      layers.splice(layers.indexOf(layer), 1);
+      removed.push({ layer, destroy });
+    },
+    raiseToTop() {},
+  };
+  let host = { collection, kind: 'globe' };
+  const cesium = {
+    Rectangle: { MAX_VALUE: { max: true } },
+    SingleTileImageryProvider: class {
+      constructor(options) {
+        this.options = options;
+      }
+    },
+  };
+  const createCanvas = (w, h) => ({
+    width: w,
+    height: h,
+    getContext: () => ({
+      createImageData: (cw, ch) => ({
+        data: new Uint8ClampedArray(cw * ch * 4),
+      }),
+      putImageData() {},
+    }),
+    toDataURL: () => 'data:image/png;base64,AAAA',
+  });
+  const imagery = createHeatImagery({
+    cesium,
+    getHost: () => host,
+    createCanvas,
+  });
+  return { imagery, layers, removed, collection, setHost: (h) => (host = h) };
+}
+
+const raster = { width: 4, height: 2, rgba: new Uint8ClampedArray(32) };
+
+test('setRaster drapes one full-globe tile and replaces it on the next build', () => {
+  const h = harness();
+  h.imagery.setRaster(raster);
+  assert.equal(h.layers.length, 1);
+  assert.deepEqual(h.layers[0].provider.options.rectangle, { max: true });
+  assert.equal(h.layers[0].provider.options.tileWidth, 4);
+  h.imagery.setRaster(raster);
+  assert.equal(h.layers.length, 1, 'never two heat layers');
+  assert.equal(h.removed[0].destroy, true);
+});
+
+test('setShow toggles without rebuilding', () => {
+  const h = harness();
+  h.imagery.setRaster(raster);
+  const layer = h.layers[0];
+  h.imagery.setShow(false);
+  assert.equal(layer.show, false);
+  h.imagery.setShow(true);
+  assert.equal(h.layers[0], layer);
+  assert.equal(layer.show, true);
+});
+
+test('setOpacity fades the same layer and survives a rebuild', () => {
+  const h = harness();
+  h.imagery.setRaster(raster);
+  const layer = h.layers[0];
+  h.imagery.setOpacity(0);
+  assert.equal(layer.alpha, 0);
+  assert.equal(layer.show, true, 'a faded layer stays mapped');
+  h.imagery.setOpacity(0.25);
+  assert.equal(h.layers[0], layer);
+  assert.equal(layer.alpha, 0.25);
+  h.imagery.setRaster(raster);
+  assert.equal(h.layers[0].alpha, 0.25, 'a rebuilt layer keeps the fade');
+  h.imagery.setOpacity(7);
+  assert.equal(h.layers[0].alpha, 1);
+});
+
+test('no imagery host keeps nothing draped; rehome brings it back', () => {
+  const h = harness();
+  h.setHost({ collection: null, kind: 'none' });
+  h.imagery.setRaster(raster);
+  assert.equal(h.layers.length, 0);
+  h.setHost({ collection: h.collection, kind: 'globe' });
+  h.imagery.rehome();
+  assert.equal(h.layers.length, 1);
+});
+
+test('destroy removes the layer', () => {
+  const h = harness();
+  h.imagery.setRaster(raster);
+  h.imagery.destroy();
+  assert.equal(h.layers.length, 0);
+});
+
+test('the shipped raster paints a lone weak fire as a distinct spot', () => {
+  // A hot cluster elsewhere sets the scale, as Africa does on real data.
+  const fires = [{ lat: 0, lon: 0, frp: 5 }];
+  for (let i = 0; i < 40; i++) {
+    fires.push({ lat: -10 + (i % 5) * 0.1, lon: 25 + i * 0.05, frp: 300 });
+  }
+  const r = buildHeatRaster(fires, HEAT_RASTER);
+  const y = Math.floor((90 / 180) * r.height);
+  const painted = [];
+  for (let x = 0; x < r.width; x++) {
+    const lon = ((x + 0.5) / r.width) * 360 - 180;
+    if (Math.abs(lon) < 5 && r.rgba[(y * r.width + x) * 4 + 3] > 0) {
+      painted.push(x);
+    }
+  }
+  const kmPerPx = 40075 / r.width;
+  assert.ok(painted.length > 0, 'the weak fire still shows');
+  assert.ok(
+    painted.length * kmPerPx <= 100,
+    `spot ${Math.round(painted.length * kmPerPx)} km wide`,
+  );
+});
diff --git a/src/layers/firms/heatVisibility.test.mjs b/src/layers/firms/heatVisibility.test.mjs
new file mode 100644
index 000000000..4926db156
--- /dev/null
+++ b/src/layers/firms/heatVisibility.test.mjs
@@ -0,0 +1,44 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { createLifecycle } from './lifecycle.js';
+
+test('reenabling an empty filtered layer never reveals the retained pre-filter heat raster', async () => {
+  let shown = false;
+  const noop = () => {};
+  const layerState = {
+    _enabled: false,
+    _viewer: {},
+    _dataSource: {},
+    _fires: [],
+    _loading: true,
+    _pickIndexById: new Map(),
+    _heatImagery: {
+      setShow(v) {
+        shown = v;
+      },
+    },
+  };
+  const lifecycle = createLifecycle({
+    layerState,
+    services: {
+      picking: { registerPickOwner: noop, unregisterPickOwner: noop },
+      sprites: { restoreSpriteOrderOnEnable: noop },
+      context: { clearSelectedEntityContextForLayer: noop },
+    },
+    config: { id: 'local-firms', overlayHost: { setVisible: noop } },
+    components: {
+      rendering: { applyHandoffFade: noop },
+      viewport: { installLodWatcher: noop, installMoveEndWatcher: noop },
+      selection: { installClickHandler: noop },
+    },
+  });
+  await lifecycle.methods.enable(layerState._viewer);
+  assert.equal(
+    shown,
+    false,
+    'empty current set must keep the old raster hidden while refresh is pending',
+  );
+  layerState._fires = [{ frp: null, confidence: null }];
+  await lifecycle.methods.enable(layerState._viewer);
+  assert.equal(shown, true, 'nonempty sets still resume their raster');
+});
diff --git a/src/layers/firms/ingestion.js b/src/layers/firms/ingestion.js
index 494ab5f1e..cb9dbd72f 100644
--- a/src/layers/firms/ingestion.js
+++ b/src/layers/firms/ingestion.js
@@ -1,5 +1,6 @@
 import { adaptFirmsRecords } from '../../data/firmsAdapt.js';
 import { fireDetectionKey } from '../../data/firmsLabels.js';
+import { filterFires } from '../../data/firmsIntensity.js';
 import { msg } from '../../i18n/index.js';
 
 export function createIngestion({
@@ -40,12 +41,13 @@ export function createIngestion({
       layerState._stale = Boolean(payload?.stale);
       const previousSelection = layerState._selectedFire;
       layerState._selectedFire = null;
-      layerState._fires = adaptFirmsRecords(payload?.fires);
-      layerState._cellCacheByGrid.clear(); // aggregation is per-dataset — new fires, new cells
-      layerState._firesByFrp = [...layerState._fires].sort(
+      layerState._allFires = adaptFirmsRecords(payload?.fires);
+      // Sorted once per payload; applyFilter only filters, so a slider drag
+      // over 200k detections never re-sorts.
+      layerState._allFiresByFrp = [...layerState._allFires].sort(
         (a, b) => b.frp - a.frp,
       );
-      layerState._count = layerState._fires.length;
+      applyFilter();
       // Data age, not response age: a stale proxy payload truthfully reads old.
       layerState._lastUpdate = Number.isFinite(payload?.fetchedAt)
         ? payload.fetchedAt
@@ -65,6 +67,7 @@ export function createIngestion({
       }
       components.rendering.renderCurrentLod(true);
       if (reselected) components.selection.selectFire(reselected, false);
+      layerState._rowControlsListener?.();
     } catch (error) {
       if (
         request.signal.aborted ||
@@ -83,6 +86,26 @@ export function createIngestion({
     }
   }
 
+  /**
+   * Run the intensity filter over the loaded payload. This is the ONE place
+   * the shown set is derived: `_fires` / `_firesByFrp` feed markers, cards,
+   * the heatmap, the context store, the top-fires query and the analyst
+   * records, so none of them can disagree about which fires exist. Cells and
+   * the heat raster are built per shown set, so their caches go with it.
+   */
+
+  function applyFilter() {
+    layerState._fires = filterFires(layerState._allFires, layerState._filter);
+    layerState._cellCacheByGrid.clear();
+    layerState._heatRaster = null;
+    layerState._firesByFrp = filterFires(
+      layerState._allFiresByFrp,
+      layerState._filter,
+    );
+    layerState._count = layerState._fires.length;
+    layerState._totalCount = layerState._allFires.length;
+  }
+
   /**
    * Find the record in the freshly-loaded set matching a previous selection.
    * Identity is the detection itself (lat/lon/acquisition time) — indices
@@ -109,5 +132,5 @@ export function createIngestion({
     },
   };
 
-  return { loadHeatmap, findMatchingFire, methods };
+  return { loadHeatmap, applyFilter, findMatchingFire, methods };
 }
diff --git a/src/layers/firms/lifecycle.js b/src/layers/firms/lifecycle.js
index 7e0b42a00..90d9cc217 100644
--- a/src/layers/firms/lifecycle.js
+++ b/src/layers/firms/lifecycle.js
@@ -14,6 +14,20 @@ export function createLifecycle({
   const { id, overlayHost } = config;
 
   const methods = {
+    /**
+     * Shell services: `imageryHost()` resolves where draped imagery goes on
+     * the active map stack (globe or 3D tiles, src/maps/imageryHost.js). The
+     * heatmap moves with it; without a host it drapes on viewer.imageryLayers.
+     * @param {{imageryHost?: () => {collection: ?Object, kind: string}}|null} services
+     */
+    attachShellServices(services) {
+      layerState._imageryHost =
+        typeof services?.imageryHost === 'function'
+          ? services.imageryHost
+          : null;
+      layerState._heatImagery?.rehome();
+    },
+
     init(viewer) {
       if (layerState._destroyed) return;
       layerState._viewer = viewer;
@@ -40,6 +54,10 @@ export function createLifecycle({
         layerState._billboards.show = true;
       }
       overlayHost.setVisible(FIRMS_OVERLAY_SOURCE_ID, true);
+      // A filter can leave an old raster cached while the current set is empty.
+      layerState._heatImagery?.setShow(layerState._fires.length > 0);
+      // The camera can have crossed the hand-off while the layer was off.
+      components.rendering.applyHandoffFade(true);
       components.viewport.installLodWatcher();
       components.viewport.installMoveEndWatcher();
       components.selection.installClickHandler();
@@ -64,6 +82,7 @@ export function createLifecycle({
       components.selection.clearFireSelection();
       if (layerState._dataSource) layerState._dataSource.show = false;
       if (layerState._billboards) layerState._billboards.show = false;
+      layerState._heatImagery?.setShow(false);
       overlayHost.clearSource(FIRMS_OVERLAY_SOURCE_ID);
       overlayHost.setVisible(FIRMS_OVERLAY_SOURCE_ID, false);
       clearSelectedEntityContextForLayer(id);
@@ -91,10 +110,21 @@ export function createLifecycle({
       components.rendering.removeDetectionCollections(viewer);
       components.selection.clearContextRegistrations();
       clearSelectedEntityContextForLayer(id);
+      layerState._allFires = [];
+      layerState._allFiresByFrp = [];
       layerState._fires = [];
       layerState._firesByFrp = [];
       layerState._cellCacheByGrid.clear();
+      clearTimeout(layerState._heatRebuildTimer);
+      layerState._heatRebuildTimer = null;
+      layerState._heatImagery?.destroy();
+      layerState._heatImagery = null;
+      layerState._heatRaster = null;
+      layerState._handoffHeat = -1;
+      layerState._imageryHost = null;
       layerState._count = 0;
+      layerState._totalCount = 0;
+      layerState._rowControlsListener = null;
       layerState._cellCount = 0;
       layerState._lastUpdate = null;
       layerState._keyRequired = false;
diff --git a/src/layers/firms/model.js b/src/layers/firms/model.js
index 9e3cf7f95..812f4f462 100644
--- a/src/layers/firms/model.js
+++ b/src/layers/firms/model.js
@@ -6,6 +6,7 @@ import {
   accentForSeverity,
   formatFrpMw,
 } from '../../data/firmsLabels.js';
+import { FRP_RAMP, frpRampStop } from '../../data/firmsIntensity.js';
 import {
   VIEW_PADDING,
   DETECTION_COLOR_STOPS,
@@ -119,27 +120,30 @@ export function createModel({
     );
   }
 
-  function heatColor(value, alpha) {
-    if (value > 0.72) return Cesium.Color.RED.withAlpha(alpha);
-    if (value > 0.42) return Cesium.Color.ORANGE.withAlpha(alpha);
-    return Cesium.Color.YELLOW.withAlpha(alpha);
+  /**
+   * The ramp stop for a fire radiative power (stepped, weakest first).
+   * Intensity alone drives the color: confidence feeds the card text and the
+   * switch, brightness is unreliable (saturates at 367 K) — see HAL-675.
+   * @param {number} frp - Megawatts.
+   * @returns {{name: string, minFrp: number, color: Cesium.Color}}
+   */
+
+  function frpColorStop(frp) {
+    const name = frpRampStop(frp).name;
+    return (
+      DETECTION_COLOR_STOPS.find((stop) => stop.name === name) ||
+      DETECTION_COLOR_STOPS[0]
+    );
   }
 
   /**
-   * Pick a sprite color stop from FRP + confidence, reusing the same
-   * yellow → orange → red thresholds as the aggregated heat cells.
+   * Pick a sprite color stop for one detection from its FRP on the shared ramp.
    * @param {Object} fire - Detection record.
    * @returns {{name: string, color: Cesium.Color}}
    */
 
   function detectionColorStop(fire) {
-    const heat = Math.min(
-      1,
-      Math.sqrt(Math.max(0, fire.frp) / 150) * 0.85 + fire.confidence * 0.15,
-    );
-    if (heat > 0.72) return DETECTION_COLOR_STOPS[0];
-    if (heat > 0.42) return DETECTION_COLOR_STOPS[1];
-    return DETECTION_COLOR_STOPS[2];
+    return frpColorStop(fire?.frp);
   }
 
   /** FRP → core marker pixel size, clamped to 8..28px. */
@@ -227,6 +231,19 @@ export function createModel({
     return fire.position;
   }
 
+  /**
+   * The anchor already built for a detection, without the floor lookup;
+   * for the far marker band, where floors are never warmed and the height
+   * difference is invisible, so tens of thousands of markers skip a cache
+   * read each per rebuild. Builds one through {@link firePosition} once.
+   * @param {Object} fire - Detection record.
+   * @returns {Cesium.Cartesian3}
+   */
+
+  function fireBuiltPosition(fire) {
+    return fire.position ?? firePosition(fire);
+  }
+
   /**
    * Occlusion-test anchor for one detection. Returns the render position
    * outright for anchors comfortably above the ellipsoid (the common case) and
@@ -234,11 +251,11 @@ export function createModel({
    * NEVER feeds rendering: the datum-correct anchor from {@link firePosition}
    * is what the sprite and the card are drawn at.
    * @param {Object} fire - Detection record.
+   * @param {Cesium.Cartesian3} [position] Its render anchor, if at hand.
    * @returns {Cesium.Cartesian3}
    */
 
-  function fireCullPosition(fire) {
-    const position = firePosition(fire);
+  function fireCullPosition(fire, position = firePosition(fire)) {
     if (fire.positionHeight >= CULL_LIFT_THRESHOLD_M) return position;
     if (!fire.cullPosition) {
       fire.cullPosition = Cesium.Cartesian3.fromDegrees(
@@ -398,8 +415,8 @@ export function createModel({
 
   /**
    * Card model for an aggregated heat cell, e.g. title "14 FIRES", detail
-   * "max 210 MW · new 3h". Accent comes from the candidate (heat-normalized
-   * score is only known at renderCells time). Exported for unit tests.
+   * "max 210 MW · new 3h". Accent comes from the candidate (renderHeat sets
+   * it with {@link cellCardAccent}). Exported for unit tests.
    * @param {{cell: Object, position: Cesium.Cartesian3, accent: string}} candidate
    * @param {number} nowMs - Current epoch milliseconds.
    * @returns {Object} firmsLabels entry.
@@ -417,7 +434,7 @@ export function createModel({
       position: candidate.position,
       cullPosition: candidate.cullPosition || candidate.position,
       gapPx: 10,
-      accent: candidate.accent || accentForSeverity('yellow'),
+      accent: candidate.accent || accentForSeverity(FRP_RAMP[0].name),
       // The count picks the plural form of the language ("حريقان (2)",
       // "14 حريقًا", "14 ПОЖАРОВ"); the card shows it in capitals like the
       // other card titles.
@@ -464,16 +481,14 @@ export function createModel({
   }
 
   /**
-   * Heat-normalized cell score → severity accent, mirroring heatColor's
-   * red/orange/yellow thresholds.
-   * @param {number} normalized - 0..1 normalized heat score.
+   * Cell card accent: the cell's strongest fire on the FRP ramp, the same
+   * color its markers take once the camera is close enough to show them.
+   * @param {{maxFrp?: number}} cell - Aggregated cell.
    * @returns {string} "r, g, b" accent string.
    */
 
-  function cellAccent(normalized) {
-    if (normalized > 0.72) return accentForSeverity('red');
-    if (normalized > 0.42) return accentForSeverity('orange');
-    return accentForSeverity('yellow');
+  function cellCardAccent(cell) {
+    return accentForSeverity(frpColorStop(cell?.maxFrp ?? 0).name);
   }
 
   /** Coordinate line like "30.512°N 75.831°E". */
@@ -579,12 +594,13 @@ export function createModel({
     boundsContainPoint,
     cellIntersectsBounds,
     heatScore,
-    heatColor,
+    frpColorStop,
     detectionColorStop,
     frpPixelSize,
     sizeBucket,
     glowSprite,
     firePosition,
+    fireBuiltPosition,
     fireCullPosition,
     cellCullPosition,
     applyHorizonCull,
@@ -593,7 +609,7 @@ export function createModel({
     buildFireCard,
     buildCellCard,
     applyFirmsOverlayPolicy,
-    cellAccent,
+    cellCardAccent,
     formatLatLon,
     formatFrp,
     formatAge,
diff --git a/src/layers/firms/policy.js b/src/layers/firms/policy.js
index 673aab871..e6f4bd664 100644
--- a/src/layers/firms/policy.js
+++ b/src/layers/firms/policy.js
@@ -1,4 +1,5 @@
 import { FIRMS_AMBIENT_COHORT_LIMIT } from '../../data/firmsLabels.js';
+import { FRP_RAMP } from '../../data/firmsIntensity.js';
 import * as Cesium from 'cesium';
 
 /** Client poll interval; the proxy's 30 min TTL is what guards upstream quota. */
@@ -6,9 +7,10 @@ import * as Cesium from 'cesium';
 export const REFRESH_INTERVAL_MS = 600_000;
 
 /**
- * LOD bands keyed by camera height. `cells` bands render aggregated
- * ground-clamped heat rectangles; `detections` bands (< ~750km plus the
- * local band) render individual fire detections as glow-sprite billboards.
+ * LOD bands keyed by camera height. `heat` bands (above ~4,500 km) drape a
+ * Snap Map–style heatmap over the globe (firmsHeatRaster.js); their
+ * `gridDegrees` aggregation only feeds the "N FIRES" cards. `detections`
+ * bands render individual fire detections as glow-sprite billboards.
  * Labels in every band go through the shared screen-space greedy declutter
  * (hard cap MAX_AMBIENT_LABELS) — there are no per-band label knobs.
  */
@@ -17,24 +19,28 @@ export const LOD_LEVELS = [
   {
     id: 'global',
     minHeight: 9000000,
-    mode: 'cells',
+    mode: 'heat',
     gridDegrees: 2.0,
     maxCells: 1800,
     labelDistance: 12000000,
   },
   {
     id: 'regional',
-    minHeight: 3000000,
-    mode: 'cells',
+    minHeight: 4500000,
+    mode: 'heat',
     gridDegrees: 1.0,
     maxCells: 3600,
     labelDistance: 8500000,
   },
   {
+    // Up to 40,000 markers: at the 3,600 km end of the hand-off the padded
+    // view over Africa, the densest region, holds ~40,000 detections, and a
+    // tighter cap left the heatmap's weak spots dissolving into nothing.
+    // A rebuild of that many costs ~60 ms, only there.
     id: 'local',
     minHeight: 750000,
     mode: 'detections',
-    maxDetections: 2500,
+    maxDetections: 40000,
     labelDistance: 4500000,
   },
   {
@@ -46,6 +52,38 @@ export const LOD_LEVELS = [
   },
 ];
 
+/**
+ * Global heat raster for the `heat` bands: ≈0.09° (≈10 km) per pixel and a
+ * one-pixel Gaussian σ, so a lone fire is a spot about the size of its
+ * marker near the hand-off and the two cross-fade without a jump;
+ * neighbours merge only when they nearly touch (σ 3 on a 2048 grid smeared
+ * each fire over ~200 km). Built once per data refresh or filter change,
+ * never per camera move.
+ */
+
+export const HEAT_RASTER = Object.freeze({
+  width: 4096,
+  height: 2048,
+  sigmaPx: 1,
+});
+
+/**
+ * Camera heights, in metres, over which the heatmap and the markers
+ * cross-fade around the 4,500 km band edge: markers alone below `from`,
+ * heatmap alone above `to`. Wider than the ±10 % band hysteresis, so
+ * whichever band is active inside it, both layers are already built.
+ */
+
+export const HANDOFF_FADE = Object.freeze({ from: 3_600_000, to: 5_400_000 });
+
+/**
+ * Trailing delay before a stale heatmap is rebuilt while one is already on
+ * screen: a slider drag fires many filter changes, and a build plus PNG
+ * encode costs a few hundred milliseconds. The first paint is immediate.
+ */
+
+export const HEAT_REBUILD_MS = 150;
+
 export const LOD_CHECK_MS = 650;
 
 /** +/-10% hysteresis on LOD band edges so slow zooms don't thrash rebuilds. */
@@ -88,10 +126,16 @@ export const CULL_LIFT_THRESHOLD_M = 10;
 
 export const CULL_LIFT_M = 12;
 
-/** Color stops shared by cell heat fills and detection glow sprites. */
+/**
+ * Color stops for detection glow sprites and card accents: the
+ * six-stop ember → white-hot FRP ramp (firmsIntensity.js), weakest first, as Cesium
+ * colors. Stop names key the glow-sprite cache and the card accents.
+ */
 
-export const DETECTION_COLOR_STOPS = [
-  { name: 'red', color: Cesium.Color.RED },
-  { name: 'orange', color: Cesium.Color.ORANGE },
-  { name: 'yellow', color: Cesium.Color.YELLOW },
-];
+export const DETECTION_COLOR_STOPS = FRP_RAMP.map((stop) =>
+  Object.freeze({
+    name: stop.name,
+    minFrp: stop.minFrp,
+    color: Cesium.Color.fromCssColorString(stop.hex),
+  }),
+);
diff --git a/src/layers/firms/queries.js b/src/layers/firms/queries.js
index 5f663cc97..34040ea43 100644
--- a/src/layers/firms/queries.js
+++ b/src/layers/firms/queries.js
@@ -1,6 +1,18 @@
 import { fireDetectionKey } from '../../data/firmsLabels.js';
-import { t } from '../../i18n/index.js';
-import { REFRESH_INTERVAL_MS } from './policy.js';
+import {
+  FIRMS_CONFIDENCE_MODES,
+  FRP_SLIDER_TICKS,
+  firePassesFilter,
+  frpForSliderPosition,
+  normalizeFireFilter,
+  rampTrackGradient,
+  sliderPositionForFrp,
+} from '../../data/firmsIntensity.js';
+import { formatNumber, t } from '../../i18n/index.js';
+import { LOD_LEVELS, REFRESH_INTERVAL_MS } from './policy.js';
+
+/** Slider resolution: whole-percent positions along the log axis. */
+const SLIDER_STEPS = 1000;
 
 export function createQueries({
   layerState,
@@ -11,6 +23,25 @@ export function createQueries({
 }) {
   const { id, name, icon, source } = config;
 
+  /** Whole-megawatt label for a slider value or tick ("0", "20", "1 000"). */
+  function frpLabel(frp) {
+    return formatNumber(frp, { maximumFractionDigits: 0 });
+  }
+
+  const confidenceLabels = () => ({
+    all: t('All', { context: 'fire confidence filter' }),
+    nominal: t('Nominal+', { context: 'fire confidence filter' }),
+    high: t('High', { context: 'fire confidence filter' }),
+  });
+
+  const confidenceTitles = () => ({
+    all: t(
+      'Every detection — many of the strongest fires are rated low confidence',
+    ),
+    nominal: t('Nominal and high confidence detections'),
+    high: t('High confidence detections only'),
+  });
+
   const methods = {
     /** Return the selected detection as a plain record for application consumers. */
     getSelectedInfo() {
@@ -51,6 +82,110 @@ export function createQueries({
     // not this interval — is what protects the upstream FIRMS quota).
     updateInterval: REFRESH_INTERVAL_MS,
 
+    /**
+     * The intensity filter as layer options (share token `w`, owner
+     * `local-firms` in layerState.js).
+     * @returns {{minFrp: number, confidence: string}}
+     */
+    getParams() {
+      return { ...layerState._filter };
+    },
+
+    /**
+     * Apply a (partial) intensity filter. Invalid fields keep their current
+     * value. The filter runs in one place (ingestion.applyFilter) and the LOD
+     * rebuild re-derives markers, cells, cards and context registrations from
+     * the shown set; a selected fire that no longer passes is deselected.
+     * @param {{minFrp?: number, confidence?: string}} params
+     * @returns {boolean} True — the request is always accepted.
+     */
+    setParams(params = {}) {
+      const next = normalizeFireFilter(params, layerState._filter);
+      if (
+        next.minFrp === layerState._filter.minFrp &&
+        next.confidence === layerState._filter.confidence
+      )
+        return true;
+      layerState._filter = next;
+      if (!layerState._allFires.length) return true;
+      components.ingestion.applyFilter();
+      if (
+        layerState._selectedFire &&
+        !firePassesFilter(layerState._selectedFire, next)
+      ) {
+        components.selection.clearFireSelection();
+      }
+      if (layerState._enabled) components.rendering.renderCurrentLod(true);
+      layerState._rowControlsListener?.();
+      return true;
+    },
+
+    /**
+     * Row controls under the Active Fires row: the log-scale minimum-FRP
+     * slider whose track is painted with the intensity ramp (so it doubles as
+     * the legend), the All / Nominal+ / High confidence switch, and the
+     * "N of M shown" counter.
+     */
+    getRowControls() {
+      const { minFrp, confidence } = layerState._filter;
+      const labels = confidenceLabels();
+      const titles = confidenceTitles();
+      const shown = layerState._count;
+      const total = layerState._totalCount;
+      return {
+        slider: {
+          id: 'min-frp',
+          label: t('Fire intensity (FRP)'),
+          ariaLabel: t('Minimum fire radiative power, megawatts'),
+          valueText:
+            minFrp > 0
+              ? t('≥ {value} MW', { value: frpLabel(minFrp) })
+              : t('All', { context: 'fire intensity filter' }),
+          min: 0,
+          max: SLIDER_STEPS,
+          step: 1,
+          value: Math.round(sliderPositionForFrp(minFrp) * SLIDER_STEPS),
+          track: rampTrackGradient(),
+          ticks: FRP_SLIDER_TICKS.map((frp) => ({
+            at: sliderPositionForFrp(frp),
+            label: frpLabel(frp),
+          })),
+          params: (value) => ({
+            minFrp: frpForSliderPosition(Number(value) / SLIDER_STEPS),
+          }),
+        },
+        segmented: {
+          id: 'confidence',
+          label: t('Confidence'),
+          ariaLabel: t('Detection confidence'),
+          options: FIRMS_CONFIDENCE_MODES.map((mode) => ({
+            id: `confidence-${mode}`,
+            label: labels[mode],
+            title: titles[mode],
+            active: mode === confidence,
+            params: { confidence: mode },
+          })),
+        },
+        info: total
+          ? t('{shown} of {total} shown', {
+              shown: formatNumber(shown),
+              total: formatNumber(total),
+            })
+          : '',
+      };
+    },
+
+    /**
+     * Install the panel's "row controls changed" callback: a load or a filter
+     * change moves the counter, and nothing else repaints the row before the
+     * next scheduled refresh.
+     * @param {(() => void)|null} listener
+     */
+    setRowControlsListener(listener) {
+      layerState._rowControlsListener =
+        typeof listener === 'function' ? listener : null;
+    },
+
     /**
      * Layer stats for the data panel. Degraded feed states surface through
      * `error` (established qa-failstate pattern: a dead feed must never look
@@ -84,7 +219,9 @@ export function createQueries({
         });
       }
       return {
+        // Shown (filtered) detections; `total` is the loaded payload.
         count: layerState._count,
+        total: layerState._totalCount,
         cells: layerState._cellCount,
         lastUpdate: layerState._lastUpdate,
         loading: layerState._loading,
@@ -172,12 +309,34 @@ export function createQueries({
       return result;
     },
 
+    /** Test seam: render one named LOD band against a near-global view. */
+    _renderLodForTest(lodId) {
+      components.rendering.renderBand(
+        LOD_LEVELS.find((level) => level.id === lodId),
+        null,
+      );
+    },
+
+    /** Test seam: one frame of the hand-off fade at the current camera. */
+    _applyHandoffFadeForTest() {
+      components.rendering.applyHandoffFade();
+    },
+
+    /** Test seam: entities drawn by the layer's data source. */
+    _entityCountForTest() {
+      return layerState._dataSource?.entities?.values?.length ?? 0;
+    },
+
     /** Test seam that binds the production click path and indexes. */
     _bindInteractionForTest(viewer, fires = []) {
       layerState._viewer = viewer;
       layerState._enabled = true;
+      layerState._allFires = fires;
+      layerState._allFiresByFrp = [...fires];
       layerState._fires = fires;
       layerState._firesByFrp = [...fires];
+      layerState._count = fires.length;
+      layerState._totalCount = fires.length;
       layerState._pickIndexById.clear();
       layerState._labelLodDistance = 1e7;
       layerState._labelCandidates = fires.map((fire) => {
diff --git a/src/layers/firms/rendering.js b/src/layers/firms/rendering.js
index 8ae445f91..9718470f8 100644
--- a/src/layers/firms/rendering.js
+++ b/src/layers/firms/rendering.js
@@ -1,7 +1,21 @@
 import * as Cesium from 'cesium';
 import { FIRMS_OVERLAY_SOURCE_ID } from '../../data/firmsLabels.js';
 import { horizonOccluder } from '../../data/iconOrientation.js';
-import { LOD_LEVELS, CONTEXT_TOP_N } from './policy.js';
+import { buildHeatRaster } from '../../data/firmsHeatRaster.js';
+import {
+  LOD_LEVELS,
+  CONTEXT_TOP_N,
+  HANDOFF_FADE,
+  HEAT_RASTER,
+  HEAT_REBUILD_MS,
+} from './policy.js';
+import { createHeatImagery } from './heatImagery.js';
+
+/** The markers drawn under the far bands' heatmap for the hand-off fade. */
+const HANDOFF_MARKER_LOD = LOD_LEVELS.find((lod) => lod.mode === 'detections');
+
+/** Fade steps: a moving camera rewrites marker colors at most this often. */
+const FADE_STEPS = 32;
 
 export function createRendering({
   layerState,
@@ -29,8 +43,11 @@ export function createRendering({
       !layerState._dataSource ||
       !layerState._fires.length ||
       !layerState._viewer
-    )
+    ) {
+      // A filter that leaves nothing shown must not leave the old heat behind.
+      if (!layerState._fires.length) layerState._heatImagery?.setShow(false);
       return false;
+    }
     const lodIndex = components.viewport.selectLodIndex(
       components.viewport.cameraHeight(),
     );
@@ -51,14 +68,54 @@ export function createRendering({
       ? components.model.paddedDegreeBounds(viewRect)
       : null;
 
-    if (lod.mode === 'detections') {
-      renderDetections(lod, bounds);
-    } else {
-      renderCells(aggregateFires(lod, bounds), lod, bounds);
-    }
+    renderBand(lod, bounds);
     return true;
   }
 
+  /**
+   * Draw one band. Markers and heatmap stay built in every band; the
+   * hand-off only fades between them.
+   * @param {Object} lod - Band descriptor.
+   * @param {?Object} bounds - Padded view bounds in degrees, or null.
+   */
+
+  function renderBand(lod, bounds) {
+    prepareHeat(lod.mode === 'heat');
+    if (lod.mode === 'detections') renderDetections(lod, bounds);
+    else renderHeat(lod, bounds);
+    applyHandoffFade(true);
+  }
+
+  const fadeColor = new Cesium.Color();
+
+  /**
+   * Cross-fade between markers and heatmap by camera height (HANDOFF_FADE),
+   * on every rendered frame, so a fast zoom never outruns the throttled band
+   * check. Cheap when nothing changed: one height read and a compare.
+   * @param {boolean} [force] Reapply, e.g. to freshly added markers.
+   */
+
+  function applyHandoffFade(force = false) {
+    const height = components.viewport.cameraHeight();
+    const t = Math.min(
+      1,
+      Math.max(
+        0,
+        (height - HANDOFF_FADE.from) / (HANDOFF_FADE.to - HANDOFF_FADE.from),
+      ),
+    );
+    const heat = Math.round(t * t * (3 - 2 * t) * FADE_STEPS) / FADE_STEPS;
+    if (!force && heat === layerState._handoffHeat) return;
+    layerState._handoffHeat = heat;
+    layerState._heatImagery?.setOpacity(heat);
+    const billboards = layerState._billboards;
+    if (!billboards) return;
+    billboards.show = layerState._enabled && heat < 1;
+    const color = Cesium.Color.WHITE.withAlpha(1 - heat, fadeColor);
+    for (let i = 0; i < billboards.length; i += 1)
+      billboards.get(i).color = color;
+  }
+
   /**
    * Bin all detections into grid cells, then viewport-clip BEFORE the
    * top-N cap so fires in view never lose their slot to higher-scoring
@@ -118,65 +175,96 @@ export function createRendering({
     return clipped;
   }
 
+  /** The heat imagery adapter, created on first use. */
+
+  function heatImagery() {
+    if (!layerState._heatImagery) {
+      layerState._heatImagery = createHeatImagery({
+        cesium: Cesium,
+        getHost: () =>
+          layerState._imageryHost?.() ?? {
+            collection: layerState._viewer?.imageryLayers ?? null,
+            kind: 'globe',
+          },
+      });
+    }
+    return layerState._heatImagery;
+  }
+
+  /** Build the heat raster from the shown set and drape it. */
+
+  function rebuildHeatRaster() {
+    clearTimeout(layerState._heatRebuildTimer);
+    layerState._heatRebuildTimer = null;
+    if (layerState._destroyed) return;
+    layerState._heatRaster = buildHeatRaster(layerState._fires, HEAT_RASTER);
+    heatImagery().setRaster(layerState._heatRaster);
+  }
+
   /**
-   * Render aggregated heat cells (global/regional bands) as ground-clamped
-   * rectangles. Cell labels do NOT live on the entities anymore — they go
-   * through the same unclamped, screen-space-decluttered label pipeline as
-   * detections (see {@link rebuildAmbientLabels}).
-   * @param {Array<Object>} cells - Aggregated cells, heat-sorted descending.
+   * Make sure the draped heatmap matches the shown set. The first paint in a
+   * far band is immediate; other builds (filter drags, refreshes, the
+   * preload under the markers) trail by HEAT_REBUILD_MS and keep the
+   * previous heatmap on screen meanwhile.
+   * @param {boolean} now Build at once when nothing is draped yet.
+   */
+
+  function ensureHeatRaster(now) {
+    if (layerState._heatRaster) return;
+    if (now && !heatImagery().hasRaster()) {
+      rebuildHeatRaster();
+      return;
+    }
+    clearTimeout(layerState._heatRebuildTimer);
+    layerState._heatRebuildTimer = setTimeout(
+      rebuildHeatRaster,
+      HEAT_REBUILD_MS,
+    );
+  }
+
+  /**
+   * Keep the heatmap draped on the current map stack and current with the
+   * shown set in every band; the hand-off fade decides how much of it shows.
+   * @param {boolean} now The camera is in a far band.
+   */
+
+  function prepareHeat(now) {
+    const imagery = heatImagery();
+    // The map stack may have changed since the last render.
+    imagery.rehome();
+    ensureHeatRaster(now);
+    imagery.setShow(layerState._enabled);
+  }
+
+  /**
+   * Far bands (global/regional): a Snap Map–style heatmap draped over the
+   * globe, transparent where nothing burns, plus the decluttered "N FIRES"
+   * cards from the coarse aggregation. The nearest band's markers are kept
+   * built underneath for the hand-off fade and hidden once it completes;
+   * cards go through the same screen-space label pipeline as detections
+   * (see {@link rebuildAmbientLabels}).
    * @param {Object} lod - Active LOD descriptor.
    * @param {?Object} bounds - Padded view bounds in degrees, or null.
    */
 
-  function renderCells(cells, lod, bounds) {
-    ensureDetectionCollections();
-    layerState._dataSource.entities.removeAll();
-    if (layerState._billboards) layerState._billboards.removeAll();
-    layerState._pickIndexById.clear();
-    layerState._cullPositions.length = 0;
-    layerState._cellCount = cells.length;
-    const maxScore = Math.max(1, ...cells.map(components.model.heatScore));
+  function renderHeat(lod, bounds) {
+    paintMarkers(HANDOFF_MARKER_LOD, bounds);
 
+    const cells = aggregateFires(lod, bounds);
+    layerState._cellCount = cells.length;
     layerState._labelCandidates = [];
     layerState._labelLodDistance = lod.labelDistance;
 
+    // Cells arrive heat-sorted, so candidate order doubles as label priority.
     for (const cell of cells) {
-      const score = components.model.heatScore(cell);
-      const normalized = Math.min(1, Math.sqrt(score / maxScore));
-      const alpha = 0.16 + normalized * 0.5;
-      const color = components.model.heatColor(normalized, alpha);
       const centerLon = cell.lonCell + lod.gridDegrees / 2;
       const centerLat = cell.latCell + lod.gridDegrees / 2;
-      const position = Cesium.Cartesian3.fromDegrees(centerLon, centerLat, 0);
-
-      layerState._dataSource.entities.add({
-        rectangle: {
-          coordinates: Cesium.Rectangle.fromDegrees(
-            cell.lonCell,
-            cell.latCell,
-            cell.lonCell + lod.gridDegrees,
-            cell.latCell + lod.gridDegrees,
-          ),
-          material: new Cesium.ColorMaterialProperty(color),
-          heightReference: Cesium.HeightReference.CLAMP_TO_GROUND,
-        },
-        position,
-        properties: {
-          count: cell.count,
-          intensity: score,
-          maxFrp: cell.maxFrp,
-          night: cell.night,
-        },
-      });
-
-      // Cells arrive heat-sorted, so candidate order doubles as label priority.
-      // Accent is resolved here because `normalized` only exists in this walk.
       layerState._labelCandidates.push({
-        position,
+        position: Cesium.Cartesian3.fromDegrees(centerLon, centerLat, 0),
         cullPosition: components.model.cellCullPosition(centerLon, centerLat),
         fire: null,
         cell,
-        accent: components.model.cellAccent(normalized),
+        accent: components.model.cellCardAccent(cell),
       });
     }
 
@@ -202,9 +290,48 @@ export function createRendering({
    */
 
   function renderDetections(lod, bounds) {
+    const markers = paintMarkers(lod, bounds);
+    if (!markers) return;
+    const candidates = markers.map((marker) => marker.fire);
+
+    layerState._cellCount = candidates.length;
+    // FRP-sorted walk: marker order doubles as label priority.
+    layerState._labelCandidates = markers;
+    layerState._labelLodDistance = lod.labelDistance;
+
+    components.cards.rebuildAmbientLabels();
+    components.selection.refreshContextRegistrations(
+      candidates.slice(0, CONTEXT_TOP_N),
+    );
+
+    if (lod.id === 'close') {
+      // Batched (chunked ≤200, sequential, session-cached) DEM warm for the
+      // rendered subset; fires are static so each coarse cell resolves once
+      // ever. Re-render ONLY when a floor actually landed — a failed resolve
+      // reports false, so this chain terminates instead of looping against a
+      // down proxy (the next camera-driven rebuild retries).
+      warmFireAnchorFloors(candidates).then((warmed) => {
+        if (!warmed || !layerState._enabled || !layerState._viewer) return;
+        const currentLod = LOD_LEVELS[layerState._currentLodIndex];
+        if (!currentLod || currentLod.mode !== 'detections') return;
+        renderCurrentLod(true);
+      });
+    }
+  }
+
+  /**
+   * The glow-sprite markers for a detections band: the strongest fires in
+   * view, capped at the band's maxDetections, horizon-culled.
+   * @param {Object} lod - Detections band descriptor.
+   * @param {?Object} bounds - Padded view bounds in degrees, or null.
+   * @returns {?Array<Object>} Label candidates for the fires drawn,
+   *   strongest first; null before the sprite collection exists.
+   */
+
+  function paintMarkers(lod, bounds) {
     ensureDetectionCollections();
     layerState._dataSource.entities.removeAll();
-    if (!layerState._billboards) return;
+    if (!layerState._billboards) return null;
     layerState._billboards.removeAll();
     layerState._pickIndexById.clear();
     layerState._cullPositions.length = 0;
@@ -226,17 +353,20 @@ export function createRendering({
       candidates = layerState._firesByFrp.slice(0, lod.maxDetections);
     }
 
-    layerState._cellCount = candidates.length;
-    layerState._labelCandidates = [];
-    layerState._labelLodDistance = lod.labelDistance;
-
+    const markers = [];
+    // Only the close band warms terrain floors (renderDetections).
+    const anchor =
+      lod.id === 'close'
+        ? components.model.firePosition
+        : components.model.fireBuiltPosition;
     for (const fire of candidates) {
       const coreSize = components.model.frpPixelSize(fire.frp);
-      const position = components.model.firePosition(fire);
-      const cullPosition = components.model.fireCullPosition(fire);
+      const position = anchor(fire);
+      const cullPosition = components.model.fireCullPosition(fire, position);
       const pickId = `firms-${fire.index}`;
       layerState._pickIndexById.set(pickId, fire);
       layerState._cullPositions.push(cullPosition);
+      markers.push({ position, cullPosition, fire, cell: null });
       layerState._billboards.add({
         id: pickId,
         position,
@@ -248,37 +378,13 @@ export function createRendering({
         horizontalOrigin: Cesium.HorizontalOrigin.CENTER,
         disableDepthTestDistance: Number.POSITIVE_INFINITY,
       });
-      // FRP-sorted walk: candidate order doubles as label priority.
-      layerState._labelCandidates.push({
-        position,
-        cullPosition,
-        fire,
-        cell: null,
-      });
     }
 
     // Freshly-added sprites default to show=true; cull the far side now so a
     // rebuild never flashes through-the-planet detections while the camera
     // sits still (the moveEnd/preRender hooks only fire on camera motion).
     refreshHorizonCulling();
-    components.cards.rebuildAmbientLabels();
-    components.selection.refreshContextRegistrations(
-      candidates.slice(0, CONTEXT_TOP_N),
-    );
-
-    if (lod.id === 'close') {
-      // Batched (chunked ≤200, sequential, session-cached) DEM warm for the
-      // rendered subset; fires are static so each coarse cell resolves once
-      // ever. Re-render ONLY when a floor actually landed — a failed resolve
-      // reports false, so this chain terminates instead of looping against a
-      // down proxy (the next camera-driven rebuild retries).
-      warmFireAnchorFloors(candidates).then((warmed) => {
-        if (!warmed || !layerState._enabled || !layerState._viewer) return;
-        const currentLod = LOD_LEVELS[layerState._currentLodIndex];
-        if (!currentLod || currentLod.mode !== 'detections') return;
-        renderCurrentLod(true);
-      });
-    }
+    return markers;
   }
 
   function ensureDetectionCollections() {
@@ -344,9 +450,11 @@ export function createRendering({
   }
   return {
     renderCurrentLod,
+    renderBand,
     aggregateFires,
-    renderCells,
+    renderHeat,
     renderDetections,
+    applyHandoffFade,
     ensureDetectionCollections,
     removeDetectionCollections,
     fireHorizonOccluder,
diff --git a/src/layers/firms/state.js b/src/layers/firms/state.js
index 48ae11db2..0b96c53ea 100644
--- a/src/layers/firms/state.js
+++ b/src/layers/firms/state.js
@@ -1,4 +1,5 @@
 import * as Cesium from 'cesium';
+import { DEFAULT_FIRE_FILTER } from '../../data/firmsIntensity.js';
 
 export function createFirmsState({ services, config }) {
   const layerState = {};
@@ -39,12 +40,39 @@ export function createFirmsState({ services, config }) {
 
   layerState._error = null;
 
+  /** Every adapted detection in the current payload, before the filter. */
+
+  layerState._allFires = [];
+
+  /** `_allFires` sorted by FRP descending, once per payload. */
+
+  layerState._allFiresByFrp = [];
+
+  /**
+   * The detections that pass the intensity filter — the ONLY set rendering,
+   * selection, cells, the top-fires query and the analyst records ever walk.
+   */
+
   layerState._fires = [];
 
   layerState._firesByFrp = [];
 
+  /** Shown (filtered) detection count. */
+
   layerState._count = 0;
 
+  /** Loaded detection count before the filter ("N of M shown"). */
+
+  layerState._totalCount = 0;
+
+  /** Minimum FRP (MW) and confidence mode; see firmsIntensity.js. */
+
+  layerState._filter = { ...DEFAULT_FIRE_FILTER };
+
+  /** Panel callback: repaint the row controls (counter) after a load. */
+
+  layerState._rowControlsListener = null;
+
   layerState._cellCount = 0;
 
   layerState._lastUpdate = null;
@@ -103,6 +131,29 @@ export function createFirmsState({ services, config }) {
 
   layerState._cellCacheByGrid = new Map();
 
+  /**
+   * Heat raster for the far bands (firmsHeatRaster.js); null = stale, rebuilt
+   * on the next far render. Cleared with the cell cache on every new shown set.
+   */
+
+  layerState._heatRaster = null;
+
+  /** Pending debounced heat rebuild (see HEAT_REBUILD_MS). */
+
+  layerState._heatRebuildTimer = null;
+
+  /** Last applied hand-off fade (0 markers … 1 heatmap); -1 forces a reapply. */
+
+  layerState._handoffHeat = -1;
+
+  /** Imagery adapter (heatImagery.js), created on the first far render. */
+
+  layerState._heatImagery = null;
+
+  /** Shell-provided imagery host resolver; falls back to viewer.imageryLayers. */
+
+  layerState._imageryHost = null;
+
   /** Camera idle snapshot so the throttled LOD check is ~free when parked. */
 
   layerState._camSnapValid = false;
diff --git a/src/layers/firms/viewport.js b/src/layers/firms/viewport.js
index 932fe2e75..b32a02e37 100644
--- a/src/layers/firms/viewport.js
+++ b/src/layers/firms/viewport.js
@@ -151,6 +151,9 @@ export function createViewport({
         // on screen throughout it — so the horizon pass below must keep running
         // while a fetch is in flight. Only the rebuild is gated on fresh data.
         if (!layerState._enabled) return;
+        // Every frame, ahead of the throttle: a fast zoom crosses the whole
+        // hand-off between two band checks.
+        components.rendering.applyHandoffFade();
         const now = performance.now();
         if (now - layerState._lastLodCheck < LOD_CHECK_MS) return;
         layerState._lastLodCheck = now;
diff --git a/src/share/viewCodec.js b/src/share/viewCodec.js
index b72f79d34..8ac00f51b 100644
--- a/src/share/viewCodec.js
+++ b/src/share/viewCodec.js
@@ -252,6 +252,7 @@ export const SHARE_VIEW_FLAGS = freezeAll([
  * written explicitly.
  */
 export const SHARE_VIEW_LAYER_OPTION_ABSENT = Object.freeze({
+  'local-firms': Object.freeze({ minFrp: 0, confidence: 'all' }),
   traffic: Object.freeze({ roadMode: null }),
   'weather-lightning': Object.freeze({ opacity: 'strong' }),
   'weather-radar': Object.freeze({ opacity: 'strong' }),
diff --git a/src/tools/queries/hazards.js b/src/tools/queries/hazards.js
index 2b11c639c..e671db426 100644
--- a/src/tools/queries/hazards.js
+++ b/src/tools/queries/hazards.js
@@ -4,6 +4,14 @@ import { suggestView } from '../views.js';
 import { defineTool, ToolError } from '../catalog.js';
 import { AREA_SCHEMA, areaContains, resolveArea } from '../area.js';
 import { LIMIT_SCHEMA, capRows, countNoun, isoTime } from '../results.js';
+import {
+  FIRMS_CONFIDENCE_MODES,
+  MIN_FRP_MW_MAX,
+  MIN_FRP_MW_MIN,
+  firePassesFilter,
+  normalizeFireFilter,
+} from '../../data/firmsIntensity.js';
+import { normalizeConfidence } from '../../data/firmsAdapt.js';
 
 function acquiredMsUtc(acqDate, acqTime) {
   if (typeof acqDate !== 'string' || !/^\d{4}-\d{2}-\d{2}$/.test(acqDate))
@@ -87,10 +95,30 @@ export const getActiveFires = defineTool({
   title: 'Active fires',
   description:
     'Satellite fire detections from NASA FIRMS in the last 24 hours within an ' +
-    'area, most intense (fire radiative power) first.',
+    'area, most intense (fire radiative power) first. Optionally limited to a ' +
+    'minimum fire radiative power in megawatts and a confidence level — the ' +
+    "same filter as the Active Fires layer's intensity controls.",
   inputSchema: {
     type: 'object',
-    properties: { area: AREA_SCHEMA, limit: LIMIT_SCHEMA },
+    properties: {
+      area: AREA_SCHEMA,
+      min_frp_mw: {
+        type: 'number',
+        minimum: MIN_FRP_MW_MIN,
+        maximum: MIN_FRP_MW_MAX,
+        description:
+          'Hide detections weaker than this fire radiative power (MW). ' +
+          'A typical detection is ~6 MW; 20 MW keeps the top tenth, 100 MW the top percent.',
+      },
+      confidence: {
+        type: 'string',
+        enum: [...FIRMS_CONFIDENCE_MODES],
+        description:
+          '"all" (default), "nominal" (nominal and high), or "high". Many of the ' +
+          'strongest fires are rated low confidence, so prefer "all" unless asked.',
+      },
+      limit: LIMIT_SCHEMA,
+    },
     required: ['area'],
     additionalProperties: false,
   },
@@ -103,9 +131,31 @@ export const getActiveFires = defineTool({
         'unavailable',
         'Fire detections need a NASA FIRMS key configured for this server',
       );
+    const filter = normalizeFireFilter({
+      minFrp: args.min_frp_mw,
+      confidence: args.confidence,
+    });
     const fires = snapshot.fires
-      .filter((fire) => areaContains(area, fire))
+      .filter(
+        (fire) =>
+          areaContains(area, fire) &&
+          firePassesFilter(
+            {
+              frp: Number(fire.frp),
+              confidence: normalizeConfidence(fire.confidence),
+            },
+            filter,
+          ),
+      )
       .sort((a, b) => (b.frp ?? 0) - (a.frp ?? 0));
+    const filterNotes = [
+      ...(filter.minFrp > 0 ? [`≥ ${filter.minFrp} MW`] : []),
+      ...(filter.confidence !== 'all'
+        ? [
+            `${filter.confidence === 'high' ? 'high' : 'nominal or high'} confidence`,
+          ]
+        : []),
+    ];
     const result = capRows(fires, args.limit);
     // The proxy serves its last good snapshot when a refresh fails, and marks
     // satellites whose download failed.
@@ -119,10 +169,16 @@ export const getActiveFires = defineTool({
     ];
     return {
       summary:
-        `${countNoun(fires.length, 'fire detection')} in ${area.label} in the last 24 hours` +
+        `${countNoun(fires.length, 'fire detection')}` +
+        (filterNotes.length ? ` (${filterNotes.join(', ')})` : '') +
+        ` in ${area.label} in the last 24 hours` +
         (notes.length ? ` (${notes.join('; ')}).` : '.'),
       data: {
         view: suggestView(services, { area, layers: ['local-firms'] }),
+        filter: {
+          min_frp_mw: filter.minFrp,
+          confidence: filter.confidence,
+        },
         stale,
         missing_sources: missing,
         fetched_at: isoTime(snapshot.fetchedAt),
diff --git a/src/tools/queries/hazards.test.mjs b/src/tools/queries/hazards.test.mjs
index fa17158dd..c1d3eb43a 100644
--- a/src/tools/queries/hazards.test.mjs
+++ b/src/tools/queries/hazards.test.mjs
@@ -44,3 +44,39 @@ test('fire acquisition timestamps preserve valid leap days and UTC times', async
     assert.equal(result.data.rows[0].acquired, expected);
   }
 });
+
+const WEEK = [
+  { lat: 24.1, lon: 121.1, frp: 864, confidence: 'l', acqDate: '2026-10-01', acqTime: '0100' },
+  { lat: 24.2, lon: 121.2, frp: 120, confidence: 'h', acqDate: '2026-10-01', acqTime: '0100' },
+  { lat: 24.3, lon: 121.3, frp: 20, confidence: 'n', acqDate: '2026-10-01', acqTime: '0100' },
+  { lat: 24.4, lon: 121.4, frp: 2, confidence: 'h', acqDate: '2026-10-01', acqTime: '0100' },
+  { lat: 30, lon: 100, frp: 500, confidence: 'h', acqDate: '2026-10-01', acqTime: '0100' },
+];
+const TAIWAN = { area: { bbox: [120, 23, 122, 25] } };
+
+test('get_active_fires shows every detection by default and reports the filter it used', async () => {
+  const result = await catalogWith(WEEK).call('get_active_fires', TAIWAN);
+  assert.deepEqual(result.data.rows.map((row) => row.frp_mw), [864, 120, 20, 2]);
+  assert.deepEqual(result.data.filter, { min_frp_mw: 0, confidence: 'all' });
+  assert.match(result.summary, /^4 fire detections in /);
+});
+
+test('get_active_fires applies the same minimum-FRP and confidence filter as the layer', async () => {
+  const catalog = catalogWith(WEEK);
+  const strong = await catalog.call('get_active_fires', { ...TAIWAN, min_frp_mw: 20 });
+  assert.deepEqual(strong.data.rows.map((row) => row.frp_mw), [864, 120, 20]);
+  assert.match(strong.summary, /^3 fire detections \(≥ 20 MW\) in /);
+
+  const nominal = await catalog.call('get_active_fires', { ...TAIWAN, confidence: 'nominal' });
+  assert.deepEqual(nominal.data.rows.map((row) => row.frp_mw), [120, 20, 2], 'the 864 MW low-confidence fire drops');
+  assert.match(nominal.summary, /\(nominal or high confidence\)/);
+
+  const both = await catalog.call('get_active_fires', {
+    ...TAIWAN,
+    min_frp_mw: 19.6,
+    confidence: 'high',
+  });
+  assert.deepEqual(both.data.rows.map((row) => row.frp_mw), [120]);
+  assert.deepEqual(both.data.filter, { min_frp_mw: 20, confidence: 'high' });
+  assert.match(both.summary, /\(≥ 20 MW, high confidence\)/);
+});
diff --git a/src/ui/kit/UiSegmented.test.mjs b/src/ui/kit/UiSegmented.test.mjs
index f15e217c6..1f2f5e983 100644
--- a/src/ui/kit/UiSegmented.test.mjs
+++ b/src/ui/kit/UiSegmented.test.mjs
@@ -117,3 +117,18 @@ test('a radio group moves from the focused option, an arrows group from the sele
   assert.deepEqual(arrows.emitted('update:modelValue'), [['a']]);
   arrows.unmount();
 });
+
+test("an option's own tip wins; an icon option without one is titled by its label", () => {
+  const wrapper = mountGroup({
+    options: [
+      { value: 'a', label: 'Alpha', attrs: { title: 'Alpha tip' } },
+      { value: 'b', label: 'Beta', icon: 'star' },
+      { value: 'c', label: 'Gamma' },
+    ],
+  });
+  const titles = wrapper
+    .findAll('button')
+    .map((b) => b.attributes('title') ?? null);
+  assert.deepEqual(titles, ['Alpha tip', 'Beta', null]);
+  wrapper.unmount();
+});
diff --git a/src/ui/kit/UiSegmented.vue b/src/ui/kit/UiSegmented.vue
index c6289658e..e1eec51a3 100644
--- a/src/ui/kit/UiSegmented.vue
+++ b/src/ui/kit/UiSegmented.vue
@@ -8,7 +8,8 @@ import { computed } from 'vue';
 // End). Each option may carry `attrs` (an id, data attributes, a tip), and
 // Core's classes sit beside the kit's: `gev-segmented`, `gev-segment` and the
 // selected option's `activeClass`. An option with an `icon` shows the glyph,
-// and its label becomes the button's accessible name and tooltip.
+// and its label becomes the button's accessible name and tooltip, unless its
+// `attrs` carry a tip of their own.
 const props = defineProps({
   modelValue: { type: String, default: undefined },
   /** `{value, label, icon?, disabled?, attrs?}`, labels already translated. */
@@ -119,7 +120,7 @@ function onKey(event) {
       ]"
       :aria-checked="String(option.value === props.modelValue)"
       :aria-label="option.icon ? option.label : undefined"
-      :title="option.icon ? option.label : undefined"
+      :title="option.attrs?.title ?? (option.icon ? option.label : undefined)"
       :disabled="optionOff(option)"
       :tabindex="tabindex(index)"
       @click="choose(index)"
diff --git a/src/ui/layerBindings.js b/src/ui/layerBindings.js
index fb8f29119..60128f8e0 100644
--- a/src/ui/layerBindings.js
+++ b/src/ui/layerBindings.js
@@ -141,6 +141,12 @@ export class LayerBindings {
       });
       this._weatherShellModules.push(layer);
     }
+    // Active Fires drapes its far-zoom heatmap on the same imagery host.
+    const fires = this._dataManager?.layers?.get('local-firms')?.module;
+    if (typeof fires?.attachShellServices === 'function') {
+      fires.attachShellServices({ imageryHost: this.services.imageryHost });
+      this._weatherShellModules.push(fires);
+    }
   }
 
   _persistAwarenessSelection(event, cleared = false) {
diff --git a/src/ui/layerPanel.js b/src/ui/layerPanel.js
index a7010d197..b24e8be7b 100644
--- a/src/ui/layerPanel.js
+++ b/src/ui/layerPanel.js
@@ -442,6 +442,8 @@ export class LayerPanel {
             this._selectChip(layerId, chipId, generation),
           onListItem: (layerId, itemId) =>
             this._selectListItem(layerId, itemId, generation),
+          onSlider: (layerId, sliderId, value) =>
+            this._moveSlider(layerId, sliderId, value, generation),
         }),
         id === null ? this._toggleContainer : this._groupContainers.get(id),
       );
@@ -471,7 +473,8 @@ export class LayerPanel {
   }
 
   /**
-   * A layer's row chips, color legend, info line and ordered list. The block
+   * A layer's row chips, one-of-many switch, slider, color legend, info line
+   * and ordered list. The block
    * is hidden while the layer is off (or while a dependency owner has
    * surrendered it), so a quiet row stays quiet. Chips and list items are
    * keyed, so the refresh a chip's own click triggers keeps keyboard focus.
@@ -495,11 +498,20 @@ export class LayerPanel {
           : `${item.label} ${formatCount(item.count)}`,
     }));
     const infoText = controls?.info ? String(controls.info) : '';
+    const segmented = controls?.segmented || null;
+    const slider = controls?.slider || null;
     // The info line, once shown, stays in place and hides when empty.
     if (infoText) row.info = true;
     return {
-      hidden: chips.length === 0 && legend.length === 0 && !infoText,
+      hidden:
+        chips.length === 0 &&
+        legend.length === 0 &&
+        !infoText &&
+        !segmented &&
+        !slider,
       chips,
+      segmented,
+      slider,
       legend,
       info: row.info
         ? { text: infoText, title: controls?.infoTitle || '' }
@@ -537,15 +549,33 @@ export class LayerPanel {
   // listeners, so a click from a released generation is dropped.
   _selectChip(id, chipId, generation = this._generation) {
     if (this._destroyed || this._generation !== generation) return;
-    const chip = this._rowControlsFor(id)?.chips?.find(
-      (entry) => entry.id === chipId,
-    );
+    // A switch option carries the same fields as a chip.
+    const live = this._rowControlsFor(id);
+    const chip = [
+      ...(live?.chips || []),
+      ...(live?.segmented?.options || []),
+    ].find((entry) => entry.id === chipId);
     if (!chip || chip.disabled || !this.isEnabled(id)) return;
     if (typeof chip.onClick === 'function') chip.onClick();
     else if (chip.params)
       this.setLayerParams(id, chip.params, { origin: 'user' });
   }
 
+  // A row slider (e.g. the Active Fires minimum-FRP filter) maps its position
+  // to params through the live descriptor on every tick.
+  _moveSlider(id, sliderId, value, generation = this._generation) {
+    if (this._destroyed || this._generation !== generation) return;
+    const slider = this._rowControlsFor(id)?.slider;
+    if (
+      !slider ||
+      slider.id !== sliderId ||
+      typeof slider.params !== 'function' ||
+      !this.isEnabled(id)
+    )
+      return;
+    this.setLayerParams(id, slider.params(value), { origin: 'user' });
+  }
+
   _selectListItem(id, itemId, generation = this._generation) {
     if (this._destroyed || this._generation !== generation) return;
     const item = this._rowControlsFor(id)?.list?.items?.find(
diff --git a/src/ui/layerPanel/LayerRows.vue b/src/ui/layerPanel/LayerRows.vue
index f404938b6..5f5d7c97e 100644
--- a/src/ui/layerPanel/LayerRows.vue
+++ b/src/ui/layerPanel/LayerRows.vue
@@ -1,6 +1,8 @@
 <script setup>
 import RailChips from '../rail/RailChips.vue';
 import RailRowList from '../rail/RailRowList.vue';
+import RowSlider from './RowSlider.vue';
+import RowSwitch from './RowSwitch.vue';
 import RowText from './RowText.vue';
 import { vClassToggle } from '../rail/classToggle.js';
 
@@ -12,6 +14,7 @@ defineProps({
   onToggle: { type: Function, default: () => {} },
   onChip: { type: Function, default: () => {} },
   onListItem: { type: Function, default: () => {} },
+  onSlider: { type: Function, default: () => {} },
 });
 </script>
 
@@ -55,6 +58,16 @@ defineProps({
           ><RailChips
             :chips="item.controls.chips"
             :on-select="(chip) => onChip(item.id, chip.id)"
+          /><RowSwitch
+            v-if="item.controls.segmented"
+            :segmented="item.controls.segmented"
+            :on-select="(optionId) => onChip(item.id, optionId)"
+          /><RowSlider
+            v-if="item.controls.slider"
+            :slider="item.controls.slider"
+            :on-input="
+              (value) => onSlider(item.id, item.controls.slider.id, value)
+            "
           /><span
             v-for="(entry, index) in item.controls.legend"
             :key="index"
diff --git a/src/ui/layerPanel/RowSlider.vue b/src/ui/layerPanel/RowSlider.vue
new file mode 100644
index 000000000..0592eac78
--- /dev/null
+++ b/src/ui/layerPanel/RowSlider.vue
@@ -0,0 +1,44 @@
+<script setup>
+import UiSlider from '../kit/UiSlider.js';
+
+// A row's quantitative slider (e.g. the Active Fires minimum-FRP filter).
+// `track` is a CSS background painting the runnable track, so a color ramp
+// doubles as the legend; each tick sits at `at` (0..1) along it. The input
+// holds its position while focused, so a refresh from its own tick never
+// moves the thumb under the pointer.
+defineProps({
+  slider: { type: Object, required: true },
+  onInput: { type: Function, default: () => {} },
+});
+</script>
+
+<template>
+  <div class="data-toggle-slider" :data-slider-id="slider.id"
+    ><div class="data-toggle-slider-head"
+      ><span class="data-toggle-slider-label">{{ slider.label }}</span
+      ><span class="data-toggle-slider-value gev-slider-value">{{
+        slider.valueText
+      }}</span></div
+    ><UiSlider
+      class="data-toggle-slider-input"
+      :data-slider-id="slider.id"
+      :min="slider.min"
+      :max="slider.max"
+      :step="slider.step ?? 1"
+      :model-value="slider.value"
+      hold
+      :aria-label="slider.ariaLabel || undefined"
+      :aria-valuetext="slider.valueText || undefined"
+      :style="slider.track ? { '--slider-track': slider.track } : undefined"
+      @update:model-value="onInput"
+    /><div class="data-toggle-slider-ticks"
+      ><span
+        v-for="tick in slider.ticks || []"
+        :key="tick.at"
+        class="data-toggle-slider-tick"
+        :style="{ '--at': `${(tick.at * 100).toFixed(2)}%` }"
+        >{{ tick.label }}</span
+      ></div
+    ></div
+  >
+</template>
diff --git a/src/ui/layerPanel/RowSwitch.vue b/src/ui/layerPanel/RowSwitch.vue
new file mode 100644
index 000000000..821da5f96
--- /dev/null
+++ b/src/ui/layerPanel/RowSwitch.vue
@@ -0,0 +1,38 @@
+<script setup>
+import UiSegmented from '../kit/UiSegmented.vue';
+
+// A row's one-of-many switch (e.g. Active Fires confidence). Options carry
+// the same fields as chips, so the owner resolves a choice the way it
+// resolves a chip; `label` is an optional caption beside the group.
+defineProps({
+  segmented: { type: Object, required: true },
+  onSelect: { type: Function, default: () => {} },
+});
+
+const options = (segmented) =>
+  (segmented.options || []).map((option) => ({
+    value: option.id,
+    label: option.label,
+    disabled: Boolean(option.disabled),
+    attrs: { 'data-chip-id': option.id, title: option.title || undefined },
+  }));
+const activeId = (segmented) =>
+  (segmented.options || []).find((option) => option.active)?.id;
+</script>
+
+<template>
+  <span
+    v-if="segmented.label"
+    class="data-toggle-segmented-label"
+    :data-segmented-caption-for="segmented.id"
+    >{{ segmented.label }}</span
+  ><UiSegmented
+    class="data-toggle-segmented"
+    :data-segmented-id="segmented.id"
+    :model-value="activeId(segmented)"
+    :options="options(segmented)"
+    :label="segmented.ariaLabel || segmented.label || ''"
+    item-class="data-toggle-segment"
+    @update:model-value="onSelect"
+  />
+</template>
diff --git a/src/ui/layerPanel/layerRows.test.mjs b/src/ui/layerPanel/layerRows.test.mjs
index 937b35074..966c41cb6 100644
--- a/src/ui/layerPanel/layerRows.test.mjs
+++ b/src/ui/layerPanel/layerRows.test.mjs
@@ -39,8 +39,123 @@ test('the count-line class toggles without dropping the voice highlight', () =>
   assert.equal(element.classList.contains('gev-voice-focus'), true);
 
   render(h(LayerRows, { items: [row(false)] }), container);
-  assert.equal(element.classList.contains('data-toggle-row--count-line'), false);
+  assert.equal(
+    element.classList.contains('data-toggle-row--count-line'),
+    false,
+  );
   assert.equal(element.classList.contains('gev-voice-focus'), true);
   assert.equal(element.classList.contains('data-toggle-row'), true);
   render(null, container);
 });
+
+const fireRow = (value, active = 'all') => ({
+  ...row(false),
+  key: 'fires',
+  id: 'fires',
+  controls: {
+    hidden: false,
+    chips: [],
+    segmented: {
+      id: 'confidence',
+      label: 'Confidence',
+      ariaLabel: 'Detection confidence',
+      options: ['all', 'high'].map((mode) => ({
+        id: `confidence-${mode}`,
+        label: mode.toUpperCase(),
+        title: `${mode} title`,
+        active: mode === active,
+      })),
+    },
+    slider: {
+      id: 'min-frp',
+      label: 'Fire intensity (FRP)',
+      ariaLabel: 'Minimum fire radiative power, megawatts',
+      valueText: value ? `≥ ${value} MW` : 'All',
+      min: 0,
+      max: 1000,
+      step: 1,
+      value,
+      track: 'linear-gradient(90deg, #9e2a1b, #fff3b0)',
+      ticks: [
+        { at: 0, label: '0' },
+        { at: 0.5, label: '30' },
+      ],
+    },
+    legend: [],
+    info: null,
+    list: null,
+  },
+});
+
+test('a row switch and slider render their markup and report choices', () => {
+  document.body.replaceChildren();
+  const container = document.body.appendChild(document.createElement('div'));
+  const chips = [];
+  const moves = [];
+  const props = {
+    onChip: (id, chipId) => chips.push([id, chipId]),
+    onSlider: (id, sliderId, value) => moves.push([id, sliderId, value]),
+  };
+  render(h(LayerRows, { items: [fireRow(0)], ...props }), container);
+
+  const caption = container.querySelector('.data-toggle-segmented-label');
+  assert.equal(caption.textContent, 'Confidence');
+  const group = container.querySelector('.gev-segmented.data-toggle-segmented');
+  assert.equal(group.getAttribute('role'), 'radiogroup');
+  assert.equal(group.getAttribute('aria-label'), 'Detection confidence');
+  const segments = [
+    ...group.querySelectorAll('.gev-segment.data-toggle-segment'),
+  ];
+  assert.deepEqual(
+    segments.map((button) => button.dataset.chipId),
+    ['confidence-all', 'confidence-high'],
+  );
+  assert.equal(segments[0].classList.contains('active'), true);
+  assert.equal(segments[1].title, 'high title');
+  segments[1].click();
+  assert.deepEqual(chips, [['fires', 'confidence-high']]);
+
+  const block = container.querySelector('.data-toggle-slider');
+  assert.equal(block.dataset.sliderId, 'min-frp');
+  assert.equal(
+    block.querySelector('.data-toggle-slider-label').textContent,
+    'Fire intensity (FRP)',
+  );
+  assert.equal(
+    block.querySelector('.data-toggle-slider-value').textContent,
+    'All',
+  );
+  const input = block.querySelector('input.data-toggle-slider-input');
+  assert.equal(input.classList.contains('gev-quantitative-slider'), true);
+  assert.equal(input.type, 'range');
+  assert.equal(input.max, '1000');
+  assert.equal(
+    input.getAttribute('aria-label'),
+    'Minimum fire radiative power, megawatts',
+  );
+  assert.equal(input.getAttribute('aria-valuetext'), 'All');
+  assert.match(
+    input.style.getPropertyValue('--slider-track'),
+    /^linear-gradient/,
+  );
+  const ticks = [...block.querySelectorAll('.data-toggle-slider-tick')];
+  assert.deepEqual(
+    ticks.map((tick) => tick.textContent),
+    ['0', '30'],
+  );
+  assert.equal(ticks[1].style.getPropertyValue('--at'), '50.00%');
+
+  input.value = '120';
+  input.dispatchEvent(new Event('input', { bubbles: true }));
+  assert.deepEqual(moves, [['fires', 'min-frp', 120]]);
+
+  // The refresh that tick triggers keeps the same nodes and updates the text.
+  render(h(LayerRows, { items: [fireRow(120, 'high')], ...props }), container);
+  assert.equal(
+    container.querySelector('input.data-toggle-slider-input'),
+    input,
+  );
+  assert.equal(input.getAttribute('aria-valuetext'), '≥ 120 MW');
+  assert.equal(segments[1].classList.contains('active'), true);
+  render(null, container);
+});
diff --git a/src/ui/styles/radio.css b/src/ui/styles/radio.css
index e491c7409..91611bf4a 100644
--- a/src/ui/styles/radio.css
+++ b/src/ui/styles/radio.css
@@ -1042,6 +1042,118 @@ html:not([lang='en']) .data-row-list-text {
   padding-top: 3px;
   overflow-wrap: anywhere;
 }
+
+/* Optional per-layer one-of-many switch (Active Fires confidence). The shared
+   .gev-segmented surface, sized to the chip row. */
+.data-toggle-controls .data-toggle-segmented {
+  flex-basis: 100%;
+  max-width: 220px;
+}
+
+.data-toggle-segmented-label {
+  flex-basis: 100%;
+  padding-top: 2px;
+  font-family: var(--font-mono);
+  font-size: 8px;
+  letter-spacing: 1.2px;
+  color: var(--text-dim);
+  text-transform: uppercase;
+}
+
+.data-toggle-controls .data-toggle-segment {
+  min-height: 20px;
+  padding: 3px 6px;
+  font-size: 8px;
+  letter-spacing: 0.8px;
+}
+
+/* Optional per-layer quantitative slider (Active Fires minimum FRP). The
+   track is painted by the layer (`--slider-track`, a stepped color ramp), so
+   the slider doubles as the marker legend; ticks sit under their thresholds. */
+.data-toggle-slider {
+  flex-basis: 100%;
+  display: grid;
+  gap: 2px;
+  padding-top: 2px;
+}
+
+.data-toggle-slider-head {
+  display: flex;
+  justify-content: space-between;
+  align-items: baseline;
+  gap: 8px;
+  font-family: var(--font-mono);
+  font-size: 8px;
+  letter-spacing: 1.2px;
+  color: var(--text-dim);
+  text-transform: uppercase;
+}
+
+.data-toggle-slider-value {
+  min-width: 0;
+  font-size: 9px;
+  letter-spacing: 0.5px;
+  text-transform: none;
+}
+
+.data-toggle-slider-input {
+  height: 14px;
+}
+
+.data-toggle-slider-input::-webkit-slider-runnable-track {
+  height: 5px;
+  border-radius: 3px;
+  background: var(--slider-track, rgba(255, 255, 255, 0.08));
+  box-shadow: inset 0 0 0 1px rgba(0, 0, 0, 0.35);
+}
+
+.data-toggle-slider-input::-moz-range-track,
+.data-toggle-slider-input::-moz-range-progress {
+  height: 5px;
+  border-radius: 3px;
+  background: var(--slider-track, rgba(255, 255, 255, 0.08));
+}
+
+.data-toggle-slider-input::-webkit-slider-thumb {
+  width: 11px;
+  height: 11px;
+  margin-top: -3px;
+  background: var(--text-primary);
+  box-shadow:
+    0 0 0 1px rgba(0, 0, 0, 0.6),
+    0 0 6px rgba(255, 255, 255, 0.35);
+}
+
+.data-toggle-slider-input::-moz-range-thumb {
+  width: 11px;
+  height: 11px;
+  background: var(--text-primary);
+  box-shadow:
+    0 0 0 1px rgba(0, 0, 0, 0.6),
+    0 0 6px rgba(255, 255, 255, 0.35);
+}
+
+.data-toggle-slider-ticks {
+  position: relative;
+  height: 10px;
+  margin: 0 5px;
+  font-family: var(--font-mono);
+  font-size: 7px;
+  letter-spacing: 0.4px;
+  color: var(--text-dim);
+}
+
+.data-toggle-slider-tick {
+  position: absolute;
+  top: 0;
+  left: var(--at);
+  transform: translateX(-50%);
+  white-space: nowrap;
+}
+
+.data-toggle-slider-tick:first-child {
+  transform: none;
+}
 /* ── Local RTL-SDR card (FM + Local ADS-B receiver) ── */
 .sdr-radio-card {
   display: grid;
diff --git a/src/voice/chatPreferences.js b/src/voice/chatPreferences.js
index b094624bb..e478620cd 100644
--- a/src/voice/chatPreferences.js
+++ b/src/voice/chatPreferences.js
@@ -22,6 +22,10 @@ export function bindChatPreferences({ ui, getDraft, setDraft }) {
       msg('Reset to globe view'),
       msg('Show earthquakes'),
     ].map((text) => t(text));
+  // Arabic short vowels and shadda are optional in writing: typing "تتبع"
+  // still finds "تتبّع".
+  const fold = (text) =>
+    text.toLowerCase().replace(/[\u064B-\u065F\u0670]/g, '');
   try {
     const stored = JSON.parse(localStorage.getItem(key));
     if (typeof stored?.quick === 'boolean') quick = stored.quick;
@@ -31,18 +35,14 @@ export function bindChatPreferences({ ui, getDraft, setDraft }) {
   function render() {
     const draft = getDraft();
     if (historyIndex >= 0 && draft !== recent[historyIndex]) resetHistory();
-    const query = draft.trim().toLowerCase();
+    const query = fold(draft.trim());
     const groups = [];
     if (query) {
       const candidates = [...recent, ...(quick ? quickCommands() : [])];
       groups.push({
         label: t('Suggestions'),
         items: [...new Set(candidates)]
-          .filter(
-            (text) =>
-              text.toLowerCase().includes(query) &&
-              text.toLowerCase() !== query,
-          )
+          .filter((text) => fold(text).includes(query) && fold(text) !== query)
           .slice(0, 4),
       });
     } else {
diff --git a/src/voice/chatPreferences.test.mjs b/src/voice/chatPreferences.test.mjs
index 916fc3342..28dcdefcb 100644
--- a/src/voice/chatPreferences.test.mjs
+++ b/src/voice/chatPreferences.test.mjs
@@ -1,5 +1,6 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
+import { setLocale } from '../i18n/index.js';
 import { bindChatPreferences } from './chatPreferences.js';
 import { createTestVoiceUi } from '../testSupport/voiceUi.mjs';
 
@@ -99,3 +100,21 @@ test('editing a recalled message ends recall, and sending resets it', (t) => {
   press('ArrowUp');
   assert.equal(field.value, 'Show live flights now');
 });
+
+test('autocomplete ignores Arabic short vowels and shadda', (t) => {
+  setLocale('ar');
+  t.after(() => setLocale('en'));
+  const ui = createTestVoiceUi();
+  let draft = '';
+  const prefs = bindChatPreferences({ ui, getDraft: () => draft });
+  t.after(() => prefs.destroy());
+  const suggested = (text) => {
+    draft = text;
+    prefs.render();
+    return ui.state.chat.suggestions.flatMap((group) => group.items);
+  };
+  // The quick command is written "تتبّع", with a shadda.
+  assert.deepEqual(suggested('تتبع'), ['اعرض تتبّع الرحلات المباشر']);
+  prefs.remember('انتقل إلى طوكيو');
+  assert.deepEqual(suggested('طُوكيو'), ['انتقل إلى طوكيو']);
+});