Agree with ^, with the addition that in Valais, particularly the Anniviers, the Itinerary Ski Routes are avvy controlled. They usually have an open/closed board at the entrance.
It's your decision...

Zinal will only be open at weekends between 13th November and 17th December, then it will open every day until 29th April.

http://www.rma.ch/anniviers/suisse/ski-valais/saison-hiver-2010-2011.html...

It rained really, really hard in the Anniviers yesterday. I expect Zermatt got some decent fresh :)