Avalanche Forecast

Good

A series of frontal systems will be sending waves of moderate precipitation amounts accompanied by strong to extreme winds through the forecast period. Model runs are in agreement with timing and precipitation amounts.Sunday night: Snow amounts 15 cm. Ridgetop winds blowing strong from the SW gusting to extreme values. Monday: Mainly cloudy with some sunny periods. Alpine temperatures -6.0. Light SW ridgetop winds with strong gusts.Tuesday: Snow 15-20 cm ramping up in the afternoon. Alpine temperatures near -5.0. Ridgetop winds moderate from the SW gusting strong. Wednesday: Light snow. Alpine temperatures near -9.0 with light SW ridgetop winds.

On Saturday, numerous natural and rider triggered slab avalanches size 1-2 and one size 4 were reported throughout the region. All elevations and aspects continue to have a storm slab problem that will likely persist through the next several days and the avalanche danger will remain high.

Another 30 cm fell overnight (with more in the forecast) adding to the storm snow amounts of up to 140 cm over the past several days. All of this storm snow is overlying a variety of old weak surfaces that developed during the past dry spell. They consist of weak facets, surface hoar, a scoured crust, wind press, or any combination of these. A poor bond exists to these old surfaces.Particularly of concern is the combination of buried facets on a crust being unusually reactive at treeline and below. Avalanche activity, whumpfing and snowpack testing at these elevations are showing easy sudden planar results on the facet/crust combo. Strong to extreme winds are shifting the new snow into deeper, and destructive wind slabs on lee slopes.The mid and lower snowpack are generally strong and well-settled. Basal facets and depth hoar are likely to exist in some parts of the region, but triggering has become unlikely.