From fc7481dca2964e80657f5b72f6b5738b467be8ba Mon Sep 17 00:00:00 2001
From: Graham McIntire <graham@mcintire.me>
Date: Mon, 20 Apr 2026 14:49:39 -0500
Subject: [PATCH] feat(weather-map): persist selected layer across navigation

---
 assets/js/weather_map_hook.ts | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/assets/js/weather_map_hook.ts b/assets/js/weather_map_hook.ts
index 9999ac16..ee3c63df 100644
--- a/assets/js/weather_map_hook.ts
+++ b/assets/js/weather_map_hook.ts
@@ -392,6 +392,12 @@ export const WeatherMap: WeatherMapHook = {
     this.gridLookup = new Map()
     this.selectedLayer = (this.el.dataset.selectedLayer || "refractivity_gradient") as LayerId
 
+    const storedLayer = localStorage.getItem("weatherMap.selectedLayer")
+    if (storedLayer && storedLayer in COLOR_SCALES && storedLayer !== this.selectedLayer) {
+      this.selectedLayer = storedLayer as LayerId
+      this.pushEvent("select_layer", { layer: storedLayer })
+    }
+
     const initialData: WeatherPoint[] = JSON.parse(this.el.dataset.weather || "[]")
     if (initialData.length > 0) {
       this.weatherData = initialData
@@ -526,6 +532,7 @@ export const WeatherMap: WeatherMapHook = {
       const newLayer = this.el.dataset.selectedLayer as LayerId | undefined
       if (newLayer && newLayer !== this.selectedLayer) {
         this.selectedLayer = newLayer
+        localStorage.setItem("weatherMap.selectedLayer", newLayer)
         this.renderLayer()
       }
     })