When I go to the mountains, I first check wetterzentrale prognostic models.
Here you can look at the weather in more detail for a few days, like temperature, amount of precipitation, thunderstorm chance, wind etc.
So I know what awaits me in the mountains
Page:
www.wetterzentrale.de When you open wetterzentrale, go to GFS-ENS, then to GFS (on the left side) and find what interests you.
Most precise forecasts up to 4-5 days, the rest always changes, GFS maps go up to 15 days.