Alert areas and period
The alert extends from the western French Alps across the Maritime Alps and the main Valais ridge from Monte Rosa to Slovenia in the south, but only from the Bernese Oberland to Glarnerland in the north. In the north, the differences will be huge, depending on the location of the boundary of the counterflow system. This means that it can vary between almost one meter and less than 30 cm over 10-20 km. However, the Goms and Gotthard regions are almost certainly still included. In France, only the very, very western foothills and the Maritime Alps will also see an alert.
South of the main ridge it's enough for an alert everywhere, but east of Switzerland it remains quite warm. So it's complicated.
From the Arlberg to the north-east, there's probably not enough for an alert, but small shifts in the air mass boundary could still cause surprises on the Arlberg. However, I expect positive surprises further west, towards northern Valais.
The alert will last until Thursday evening or Friday morning in the southeast.
Wind
The wind will remain fairly tame for the amount of fresh snow and will only become stormy at the very top. Especially in the core of the counter-current system, there is also good powder at the top. And you can see why this weather situation is the freerider's favorite, at least in central Switzerland!
However, the relatively low wind speeds mean that it doesn't push as much outside the core up to the main ridge.