What happened to the Persistent Weak Layer problem? The PWL problem first appeared in the December 12 forecast, and since that time numerous large natural and human-triggered avalanches have occurred, failing on the layer of faceted snow down near the ground on mid and upper elevation aspects facing west, north, and east. This PWL formed from snowfall in October and early November that weakened during the prolonged dry spell through November and early December. Heavy snowfall in December and early January snowfall placed a 3-5' deep slab of strong/dense snow on top of this layer (as shown in this photo by Meredith Johnson) and it is now unlikely a skier or rider could affect this deeply-buried layer. Although we may not have any remaining issues with this PWL this season, for now we are saying the PWL problem has become dormant as it may again become reactive with future storms.

This information does not apply to developed ski areas or highways where avalanche control is normally done. This forecast is from the U.S.D.A. Forest Service, which is solely responsible for its content. This forecast describes general avalanche conditions and local variations always occur.