Avalanche Forecast
Regions: Northwest Inland.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Wednesday night-Thursday: snow amounts 5-10 cm with light winds gusting extreme from the SW. Alpine temperatures near -3 and freezing levels 1000 m. Friday: Periods of snow 2-7 cm. Ridgetop winds light gusting to 65 km/hr from the SW. Alpine high of -8 and freezing levels falling to 500 m. Saturday: Mostly cloudy with sunny periods. Ridgetop winds generally light. Alpine temperatures high of -10 and freezing levels at valley bottom.
Avalanche Summary
On Tuesday, no new avalanche activity was reported. With forecast snow and strong winds, reactive wind slabs are likely over the next several days.
Snowpack Summary
New snow 5- 15 cm accompanied by strong- extreme SW winds is burying a plethora of old snow surfaces including isolated wind slabs and wind press, sun crusts, and surface hoar. The new snow may have a poor bond to these interfaces. At treeline elevations the average snowpack depths are 150-190 cm and a well consolidated mid-pack of approximately up to 100 cm sits above weak basal facets (sugary snow) near the ground. Recent snowpack testing has shown sudden results down 100 cm within the facetted snow. Although possibly a low probability for triggering the persistent slab exists, the consequence would be high as it has the potential to produce very large destructive avalanches especially in shallower snowpack areas.
Avalanche Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 1 - 2
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Unlikely
Expected Size: 2 - 4