wrong ground level and underground wind ?!
in the alps, the forecast is give at ground level equal to sea level. so you get +10' instead of -5' as well as no wind, while its blowing.
you are just 2000m under the ground !!!
In the Alps the forecast is given at ground level, not at sea level.
You must know that global models with resolution such as 9km may give in mountains some inaccuracies. See models with higher resolution like ICON-EU or AROME.