Avalanche Forecast
Issued: Dec 22nd, 2021 4:07PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Loose Dry.
Lisa Paulson,
Wind slab development continues with strong winds and new snow forecasted. On Christmas Eve we slide into a period of dangerously cold temperatures for the foreseeable future....
Summary
Weather Forecast
Moderate to strong SW winds are forecasted to continue as a low pressure system pulls away from the region delivering 5-15 cm overnight, and possibly another 10 on Thursday as a cold front passes mid-day tomorrow. Behind the cold front, temperatures will drop and winds will ease. Fri-Sat cold arctic air becomes entrenched (highs in the minus 20's)
Snowpack Summary
Strong winds with up to 20 cm tonight and Thurs will contribute to the windslab problem, most notably around Louise & Hwy93N. There is 40-60 cm over the Dec 2 rain crust (exists below 2200m) but is not yet active. We are monitoring it closely. The lower snowpack is well settled but shallow areas (<100 cm) may still have a DPS issue near the ground.
Avalanche Summary
Both SSV and LL ski area report thin wind slab formation from strong winds on Wednesday to size 1.5. Also noted a ~3 day old unusual size 2 avalanche at 2000m on Tumbling Peak in a very shallow snowpack area. Looked like someone may have taken a nasty ride.
Confidence
Forecast snowfall amounts are uncertain
Problems
Wind Slabs
New snow and strong winds are creating windslabs that may bond poorly to the old surface. Manage your terrain choices carefully on Thursday to avoid leeward areas.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Expect this problem to develop in areas that receive higher amounts of new snow (~20 cm). Weather models vary from 5-25 cm forecasted.
- Be careful of loose dry power sluffing in steep, confined or exposed terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 23rd, 2021 4:00PM
