Avalanche Forecast
Issued: Apr 22nd, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Dry and Wind Slabs.
Tim Haggarty,
With additional snow expected Friday and minimal solar input forecast, we expect an "all freeze, no melt" scenario for the snowpack.
Click the "More Spring Conditions details" link found below for supporting information on this scenario and others.
Summary
Weather Forecast
Freezing levels appear to have reached around 2000m Thursday with thin cloud cover in the afternoon. Friday a westerly flow will bring an additional 5 to 15 cm and winds that may touch into the moderate range. Freezing level should be kept under 1800m again with cloud cover forecast through the day.
Snowpack Summary
10 to 20 cm of new snow has buried crusts on all aspects to 2200m and to ridgecrests on solar slopes. There are several persistent layers in the mid to lower snowpack that are likely only a concern on alpine north facing terrain where no crusts are found in the snowpack while temperatures remain cool.
Avalanche Summary
During the warmup, persistent layers in the mid and lower snowpack were re-activated in a few instances with cornices and explosives, producing large avalanches, but activity has tapered since.
Confidence
Problems
Loose Dry
5-20 cm of new snow will be sitting over surface crusts on all but high north aspects. Expect this snow to sluff naturally in extreme terrain and with skier traffic in steep terrain. Additional snowfall will contribute to this problem on Friday.
- Use caution above cliffs where small avalanches may have severe consequences.
- Be very cautious with gully features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Winds out of the north east reached moderate values as the new snow arrived. Some thin new slabs are likely to have formed. More snow with west winds may contribute to this problem Friday.
- Use caution on steep lee and cross-loaded slopes.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 23rd, 2021 4:00PM
