I stand corrected; thank you.
My comments on radar and MSLP still stand. No apparent high altitude weather.
From
here
METAR LSGS 111220Z VRB03KT 9999 FEW110 11/M07 Q1019 NOSIG
TAF LSGS 111125Z 1112/1121 VRB03KT 9999 FEW110
BECMG 1113/1115 CAVOK=
No real difference.
This shows nothing before 1800Z now but you can see no significant high altitude cloud over most of Switzerland.
I am no crash investigator but to me it looks like they tried to land along the top of the ridge but thoroughly stalled and hit the ground with a high vertical speed and low horizontal speed. A bit like the Turkish B737 in Amsterdam. The huge (1m) boulder about 2m behind the elevator seems undisturbed. Except for footprints, the snow is undisturbed all around.