Avalanche Forecast
Issued: Mar 29th, 2021 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
jcoulter,
Avalanche Canada
Continued wind loading and spring sun on recent storm snow may up the sensitivity for rider trigged avalanches or cause a natural cycle that tips into the HIGH range briefly on Tuesday. Continue to make conservative terrain choices while new snow stabilizes.
Summary
Confidence
Moderate - Uncertainty is due to how the snowpack will react to the forecast weather. Uncertainty is due to the limited number of field observations.
Weather Forecast
There is some uncertainty between weather models about the extent of cloud cover during the day on Tuesday. Sunnier skies may increase the likelihood of both natural and human triggered avalanches. Continued moderate to strong winds will also be driving avalanche concerns.
MONDAY NIGHT - Clearing overnight / moderate northwest wind / alpine low temperature near -11 / freezing level at valley bottom
TUESDAY - Mostly sunny / moderate to strong west wind / alpine high temperature near -4 / freezing level 1400 m
WEDNESDAY - Mostly clear / moderate south west wind / alpine high +3 /freezing level 2100 m
THURSDAY- Potential for no overnight freeze / partly cloudy / alpine high +5 / freezing level 2300 m
Avalanche Summary
Widespread natural avalanches up to size 2.5 and skier controlled avalanches up to size 2 were reported on Monday.Â
Storm slabs reactive to human triggering are still expected on Tuesday, especially in wind loaded areas or on sunny aspects. Sunny skies on Tuesday could cause a quick uptick in natural avalanche activity as well.
Glide cracks continue to grow. This serves as a great reminder to avoid slopes with glide cracks on them at all times. They are inherently unstable and can release at any time.
Snowpack Summary
By Monday we had 30-55 cm of recent storm snow in sheltered areas, and more where there was wind loading from moderate to strong southwest to northwest winds. Soft slabs formed in lee features and around ridge crests and cornices continued to grow.
Only southerly aspects, slopes below treeline got moist on Monday.
Forecast moderate to strong westerly winds on Tuesday could be wind affecting exposed snow surfaces, transporting snow and building new slabs again in open lee terrain.
Recent storm snow sits variety of old surfaces such as crusts on all but north aspects in the alpine and treeline and crusts at all elevations below 1700 m.Â
The mid-pack and lower snowpack is generally well settled and strong.
Terrain and Travel
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Even brief periods of direct sun could produce natural avalanches.
- Be especially cautious as you transition into wind affected terrain.
- Carefully monitor the bond between the new snow and old surface.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Storm slabs are expected to stay reactive throughout the day, especially in wind loaded terrain and/or when sun is on the slopes.
Monitor the bond of the new snow to old surfaces before committing to any terrain with consequences.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Recent strong southwest through northwest winds have been building fresh cornice growth.
Cornices falls can be a hazard on their own, and can also act as a trigger for avalanches on the slopes below.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 30th, 2021 4:00PM
