Merge pull request #954 from akrherz/gh953_xh

✨ Add VTEC XH Code (Extreme Heat)

Author: akrherz

CHANGELOG.md

@@ -22,6 +22,7 @@ All notable changes to this library are documented in this file.
 memcache is short circuited.
 - Store `product_id` for PIREPs and do some faked AFOS assignments to help.
 - Support SPC afternoon Day 3 outlook (cycle assigned as 20) (#936).
+- Support VTEC significance addition of Extreme Heat (XH) (#953).
 
 ### Bug Fixes
 

src/pyiem/nws/vtec.py

@@ -107,6 +107,7 @@
     "WI": "Wind",
     "WS": "Winter Storm",
     "WW": "Winter Weather",
+    "XH": "Extreme Heat",  # March 2025
     "ZF": "Freezing Fog",
     "ZR": "Freezing Rain",
 }
@@ -217,6 +218,8 @@
     "WS.A": "#4682B4",
     "WS.W": "#FF69B4",
     "WW.Y": "#7B68EE",
+    "XH.A": "#800000",  # maroon
+    "XH.W": "#C71585",  # medium violet red
     "ZF.Y": "#008080",
     "ZR.Y": "#DA70D6",
 }