Avalanche Forecast
Issued: Dec 14th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
Aaron Beardmore,
There is uncertainty regarding wind slabs in the alpine due to minimal observations. Benign weather and a dive in temperature Thurs/Fri will continue to improve conditions.
Summary
Weather Forecast
Light snowfall associated with cloud and moderate west wind is expected over the next 2 days. Alpine temperatures are expected to drop into the -20 range on Thursday.
Snowpack Summary
20-30 cm of low density snow surface snow is bonding well with only limited windslab development at treeline and the low alpine. Our concern is growing for weaknesses developing above the Dec 2 rain crust, now buried 60-80 cm at treeline elevations (below 2250). Watch carefully as this weakness develops into an avalanche problem in the coming days.
Avalanche Summary
No new natural avalanches have been reported. Both LL and SSV ski areas report windslabs up to size 1 in their alpine areas.
Confidence
Problems
Wind Slabs
We suspect this problem exists in the high alpine, where we have no observations. Ski hills have been reporting minimal windslab action, but we expect they exist above 2500 meters in leeward areas.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
This layer has stabilized over the past few days and we have not seen an avalanche on it for 9 days. The weakness remains and the problem is not gone, just dormant for now. Continue to very wary of large alpine terrain features.
- Avoid steep convexities or areas with a thin or variable snowpack.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2021 4:00PM
