fix(cyclones): label NHC classification codes by their published meanings

src/i18n/locales/es.json

@@ -1153,6 +1153,7 @@
   "OpenStreetMap · community mapped": "OpenStreetMap · mapeado por la comunidad",
   "Atlantic and eastern/central North Pacific; not worldwide cyclone coverage.": "Atlántico y Pacífico Norte oriental/central; no es una cobertura mundial de ciclones.",
   "Potential tropical cyclone": "Posible ciclón tropical",
+  "Post-tropical cyclone": "Ciclón postropical",
   "Hurricane": "Huracán",
   "Tropical storm": "Tormenta tropical",
   "Tropical depression": "Depresión tropical",

src/i18n/locales/ru.json

@@ -1169,6 +1169,7 @@
   "OpenStreetMap · community mapped": "OpenStreetMap · данные сообщества",
   "Atlantic and eastern/central North Pacific; not worldwide cyclone coverage.": "Атлантика и восточная/центральная часть северного Тихого океана; покрытие циклонов не глобальное.",
   "Potential tropical cyclone": "Потенциальный тропический циклон",
+  "Post-tropical cyclone": "Посттропический циклон",
   "Hurricane": "Ураган",
   "Tropical storm": "Тропический шторм",
   "Tropical depression": "Тропическая депрессия",

src/i18n/locales/zh-CN.json

@@ -530,6 +530,7 @@
   "Cyclone advisories unavailable": "气旋公告不可用",
   "Cyclone data unavailable": "气旋数据不可用",
   "Potential tropical cyclone": "潜在热带气旋",
+  "Post-tropical cyclone": "后热带气旋",
   "Hurricane": "飓风",
   "Tropical storm": "热带风暴",
   "Tropical depression": "热带低压",

src/layers/cyclones/index.js

@@ -41,13 +41,16 @@ const ADVISORIES_UNAVAILABLE = msg('Cyclone advisories unavailable');
 const SERVER_REASONS = new Set([msg('Cyclone data unavailable')]);
 const errorText = (error) =>
   error && (SERVER_REASONS.has(error) ? t(error) : translateKnown(error));
+// NHC's Tropical Cyclone Status JSON reference: PTC is post-tropical, PC is a
+// potential tropical cyclone, and subtropical systems are STS and STD.
 const CLASSIFICATION_NAMES = Object.freeze({
-  PTC: msg('Potential tropical cyclone'),
+  PC: msg('Potential tropical cyclone'),
+  PTC: msg('Post-tropical cyclone'),
   HU: msg('Hurricane'),
   TS: msg('Tropical storm'),
   TD: msg('Tropical depression'),
-  SS: msg('Subtropical storm'),
-  SD: msg('Subtropical depression'),
+  STS: msg('Subtropical storm'),
+  STD: msg('Subtropical depression'),
 });
 const classificationName = (code) =>
   Object.hasOwn(CLASSIFICATION_NAMES, code)

src/layers/cyclones/index.test.mjs

@@ -513,12 +513,13 @@ test('only the latest queued focus runs and an unchanged selection survives refr
 });
 test('classification display expands known codes without altering the source or guessing unknown meanings', async () => {
   for (const [code, label] of [
-    ['PTC', 'Potential tropical cyclone'],
+    ['PC', 'Potential tropical cyclone'],
+    ['PTC', 'Post-tropical cyclone'],
     ['HU', 'Hurricane'],
     ['TS', 'Tropical storm'],
     ['TD', 'Tropical depression'],
-    ['SS', 'Subtropical storm'],
-    ['SD', 'Subtropical depression'],
+    ['STS', 'Subtropical storm'],
+    ['STD', 'Subtropical depression'],
     ['EX', 'EX'],
     ['UNKNOWN', 'UNKNOWN'],
   ]) {