Avalanche Forecast

Moderate - Forecast snowfall amounts are uncertain on Wednesday

A series of low pressure systems will sweep across the Interior tonight through tomorrow bringing precipitation and light-moderate winds. A clearing trend with an associated ridge will start to set up later Thursday into Friday. Wednesday: Snow amounts  5-10 cm through the day. Ridgetop winds will be moderate from the West and freezing levels near 1500 m. Thursday: Mostly cloudy with possible sunny breaks. Ridgetop winds light-moderate from the NW. Alpine temperatures near -7 and freezing levels 1500 m. Friday: Mostly cloudy with alpine temperatures high of -2 and freezing levels 1700 m.

On Monday, a natural cornice fall up to size 2 was observed. With continued precipitation and wind, natural avalanche activity may continue. Fragile cornices are also suspect, they are large enough and act as heavy triggers for deeper slab avalanches to release on the slopes below. If you're traveling below treeline where the avalanche hazard is lower than it is in the alpine you should remain diligent with your terrain use, mitigate overhead hazards by avoiding or lingering in run-out zones where large avalanches could come down from above. We remain in a low probability, high consequence scenario for persistent slab avalanches failing on deeply buried weak layers. Check out the recent Forecaster Blogs for more details.

Up to 20 cm of recent storm snow has fallen at upper elevations. This now brings 30-70 cm of accumulated snow over the past week which overlies a rain crust below 2000 m or a sun crust on solar aspects at higher elevations. New wind slabs are developing on leeward slopes and behind terrain features and large, fragile cornices exist along ridgelines. At lower elevations, there may be multiple crust layers in the upper snowpack which are now generally bonded. At higher elevations, the February weak layers are down 120-150 cm and woke up during last week's storm with many avalanches stepping down to them. The deep mid-December facet layer and November rain crust both still linger near the bottom of the snowpack and a few avalanches and cornice falls have also stepped down to these layers last week resulting in some very large full depth avalanches.