No overnight freeze combined with 3000m freezing levels means less window for safe travel, even early in the morning. Steer clear of steep slopes when they are moist or wet and give cornices a wide birth. Check out the Forecaster's Blog for information on spring conditions.
Summary
Confidence
Weather Forecast
FRIDAY NIGHT: Clear / light, south to southwest ridgetop wind / alpine low temperature +4 / Freezing level 3000 m.
SATURDAY: Sunny / light, southwest ridgetop wind / alpine high temperature +8 / freezing level 3000 m.
SUNDAY: Partly coudy, clearing in the afternoon / strong, east ridgetop wind / alpine high temperature +5 / freezing level dropping to 1600 m.
MONDAY: Sunny / wind easing back to light southwest / alpine high temperature +7 / freezing level 2400 m
Avalanche Summary
Numerous natural and explosives triggered wet loose and cornice failures avalanches in the size 2-3 range have been reported in the last few days on all elevations and aspects. Glide avalanches have also been reported.
Snowpack Summary
Lingering wind slabs may still be reactive in isolated locations on steep northerly aspects in the alpine that still have dry snow. All other terrain has been undergoing a melt-freeze cycle with successive days of warm sunny weather. Things will be "more melt, less freeze" on Saturday as we do not expect a good overnight recovery.
Strong solar radiation and warming will trigger more wet loose avalanches on Saturday as the snow loses cohesion. Cornices are large and fragile. Cornice falls could trigger large avalanches on the slopes below.
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
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- 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.
- Extra caution is needed around cornices under the current conditions.
Problems
Loose Wet
With multiple nights of no overnight refreeze, expect natural and human triggered wet loose avalanches on a variety of aspects and elevations. Danger will be greatest on steep sun exposed slopes.
The more the snowpack warms-up and weakens, the more conservative you'll want to be with your terrain selection. Wet loose avalanches can entrain a lot of snow and cross elevation bands.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Strong solar radiation and warming will likely trigger the large cornices that hang over ridge lines. Cornice falls are a hazard on their own, but could also trigger large avalanches on the slopes below.
Aspects: North, North East, East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 17th, 2021 3:00PM
