The best and safest riding will be in north-facing terrain that is free from cornices overhead. Avalanche danger will be MODERATE when slopes are exposed to the sun.
Summary
Confidence
Moderate - Uncertainty is due to rapidly fluctuating freezing levels.
Weather Forecast
Warm sunny weather continues until a weak frontal system arrives on Thursday.
TUESDAY NIGHT: Clear skies, light northeast wind, freezing level drops to valley bottom with treeline temperatures dropping to -6 C.
MONDAY: Sunny, light wind, freezing level climbs to 2200 m with treeline temperatures reaching 0 C.
WEDNESDAY: Sunny with some clouds in the afternoon, light northwest wind, freezing level climbs to 2400 m with treeline temperatures reaching +2 C.
THURSDAY: Scattered flurries bring 5-10 cm of snow above 1800 m and light rain in the valleys, moderate northeast wind, freezing level around 1800 m with treeline temperatures around -2 C.
Avalanche Summary
Multiple days of above freezing temperatures resulted in widespread size 1-2 wet loose avalanches on sun-exposed slopes between Thursday and Saturday. There were also likely a few larger wet slab avalanches during this period, such as the one reported near the Bugaboos on Saturday in this MIN report. There were also natural cornice failures over this period, some as big as size 3. The last report of a persistent slab avalanche was from March 8 in the Golden area where a cornice fall triggered a size 3 avalanche on an steep east-facing slope in the alpine.
You can still expect wet loose avalanches and cornice falls on Tuesday, but they will be less widespread than they were over the weekend due to the relatively cooler temperatures.
Snowpack Summary
A surface crust will form overnight and then gradually break down with daytime warming. Dry snow may still be found in high north-facing terrain (above roughly 2300 m). While there have been no recent avalanches on buried weak layers, there are a few layers that could potentially be triggered during periods of intense warming or by a large cornice fall. This includes a 30-60 cm deep crust layer from mid-March and the early November crust near the bottom of the snowpack.
Terrain and Travel
- Avoid being on or under sun exposed slopes.
- When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
Problems
Loose Wet
Expect wet loose avalanches to run naturally when steep slopes are exposed to the sun. Activity will start on east-facing slopes in the morning, south-facing slopes throughout the day, and continue on west-facing slopes into the evening.
Aspects: East, South East, South, South West, West.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Cornices are large and fragile when exposed to the sun. Cornice falls are dangerous on their own and can possibly trigger avalanches on slopes below.
Aspects: North, North East, East, South East, South.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 20th, 2021 4:00PM
