Wet loose avalanches become increasingly likely during the heat of the day. Back off slopes as the surface becomes moist or wet with daytime warming and avoid slopes with large cornices overhead.
Summary
Confidence
High -
Weather Forecast
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WEDNESDAY NIGHT: Mostly clear / Moderate, northwest ridgetop wind / alpine low temperature -5 / Freezing level 800 m.
THURSDAY: Mostly sunny / Light, northwest ridgetop wind / alpine high temperature 3 / Freezing level 1500 m.
FRIDAY: Mostly sunny / Light, west ridgetop wind / alpine high temperature 3 / Freezing level 1500 m.
SATURDAY: Mostly sunny / Light, southeast ridgetop wind / alpine high temperature 2 / Freezing level 1300 m.
Avalanche Summary
No new avalanches were reported in this region on Tuesday. However, observations are very limited this time of year.
Over the weekend, there were reports of numerous large (size 2) wet loose avalanches on south-facing slopes at all elevations and a few large (size 2-2.5) cornice failures on a variety of aspects.Â
One wet slab was suspected to have released on the November crust layer on a shallow west aspect in the alpine, triggered by a loose wet avalanche from above. Cornice fall, loose wet avalanches, or a rider hitting a thin spot in the snowpack should be considered if riding on steep, rocky slopes with a shallow or thin to thick snowpack as they are the most likely ways to trigger deeply buried weak layers.
Snowpack Summary
The snowpack has been undergoing a melt-freeze cycle with successive days of warm sunny weather. Strong solar radiation and warming will likely initiate wet loose avalanches as the snow loses cohesion. As the heat penetrates deeper into the snowpack, operators have reported larger wet slab avalanches. These avalanches are dense, destructive, and can run far, reaching otherwise snow-free valley bottoms. Cornices are large and looming along ridgelines. Sun and warm temperatures will increase the chances of cornice failures, especially when temperatures remain above zero overnight. Check out the Forecaster's Blog for information on how to manage these spring conditions.Â
The snowpack is overall strong and settled in most areas, however, sustained warming can increase the likelihood of large avalanches failing on deeply buried weak layers. This is most likely to occur on steep, rocky alpine slopes with a shallow or thin to thick snowpack.
Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.
Terrain and Travel
- Avalanche hazard is expected to to increase througout the day, think carefully about your egress.
- Back off slopes as the surface becomes moist or wet with rising temperatures.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
Problems
Loose Wet
Wet loose avalanches become increasingly likely during the heat of the day.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Large cornices hang like Gargoyles over alpine ridgetops. Cornice falls can trigger large avalanches on slopes below that a single rider may not trigger.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 22nd, 2021 4:00PM
