Avalanche Forecast
Issued: Nov 30th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Wet.
ahanna,
Avalanche Canada
Avalanche danger will rise to CONSIDERABLE in the afternoon as temperatures rise at upper elevations. Use extra caution where recent snow is experiencing sun and rapidly warming temperatures for the first time.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
Monday night: Clear, light northwest wind, freezing level 800 m.
Tuesday: Clear, light northwest wind, freezing level spiking in the afternoon 800 to 3000 m.
Wednesday: Sunny, moderate southeast wind, freezing level 3000 m.
Thursday: Sunny, moderate south wind, freezing level 1800 m.
Avalanche Summary
Tuesday we may see storm slab avalanches due to rapidly warming temperatures and sun in the afternoon. They may be especially reactive where recent snow sits over a crust. Loose wet avalanches are also be possible, especially on steep solar aspects.Â
Our eyes and ears in the mountains are limited at this time of year and may continue this winter due to fewer professional observations. If you see anything (or don't) while out in the field, please consider sharing via the Mountain Information Network (MIN). Photos are especially helpful! Thank you so much for all the great MINs submitted so far!
Snowpack Summary
Around 30 cm of recent snow and southwest winds have formed fat pockets of storm slab in lee features at upper elevations. Elevations above 1400 m where dry snow fell will feel the greatest impact from rapidly warming temperatures Tuesday afternoon. Below 1200 m, most of the recent snow fell as rain on a soggy snowpack.
The snow line currently sits at around 900 m. Snowpack depth rapidly changes with elevation. The snowpack rapidly jumps to around 100 cm deep above 1000 m and between 150 to 200 cm near the mountain tops.
Terrain and Travel
- Extra caution for areas experiencing rapidly warming temperatures for the first time.
- Avoid steep slopes when air temperatures are warm, or solar radiation is strong.
- Be cautious of buried obstacles especially below treeline.
Problems
Storm Slabs
A sharp rise in temperature coupled with solar radiation, will promote rapid settlement and accelerated slab development in the recent storm snow Tuesday afternoon. Be especially wary of steep south aspects at upper elevations, where recent snow is both receiving direct sun and may be sitting on a crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
A rapidly warming snow surface may release loose wet avalanches, especially in areas where the snow surface has already been saturated by recent rain. Pinwheeling is a good indicator of this type of instability.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 1st, 2020 4:00PM
