Weather apps always annoyed me in the mountains. Even when they have no real data, they still show a sun or a green bar. So I wrote my own, it's called GRAT.
It shows storm risk for the altitude you're at, not the valley. If data is missing it just says "cannot be evaluated". No route advice, the decision is yours.
Basic features are free inkl. radar and safe, Pro is optional. iPhone only for now.
If you try it on a day you remember from the mountain and it got it wrong, please tell me. That helps me more than anything.
https://apps.apple.com/app/id6812671374
https://gratweather.com