It has already started to snow and will continue until Saturday. The snowfall will last longer in the north and will probably bring a good, cold bonus, but I can't in good conscience predict powder for such a long time. There may be an update on Friday evening. Especially from the Arlberg to the east, there could be the icing on the cake!
Alert period
Until Friday evening, but it will continue to snow until Sunday.
Alert area
From the Arlberg to the Hautes Alpes and generally the whole north-western Alpine arc with a core from the lower Valais/northern Valais to the Hautes Alpes. Some models also see higher amounts on the Arlberg, but these are not the most reliable. From experience, the flow also tends to fit my classification.
Snowfall line
Now at around 1500, but that quickly drops to the very bottom and means fluffy powder wherever there's no wind. So full amounts should be available from 1000m.
Wind
Still fresh to strong, but not full gale or hurricane force. The wind will blow from the west and later from the north. This will bring snow, but should also leave sheltered areas.