Old weak snow (a Persistent Weak Layer) from October is now buried from early December snow storms and has just gotten prodded big time by this big storm. It is not going to be happy. Natural avalanches are almost certain today on upper elevation northwest, north and northeast facing slopes. Do not screw around with any of these steep slopes and be sure to stay well clear of run-out zones. That means make sure that even if you are on low angle terrain that there are no steep slopes above you. It is VERY possible that you can trigger an avalanche from a distance today. This means you could trigger an avalanche from flat terrain that could come down from steep slopes above you and bury you.

The new snow itself could be unstable today especially if the wind increases again later on. Whenever we deal with this much snow in a short period of time, you must treat it as guilty until proven innocent. Watch for cracking in the snow surface to give you clues to whether the new snow is unstable. The best approach is to let the storm take its course and stay out of avalanche terrain until we get a handle on how all this new snow is behaving.