Avalanche Forecast
Issued: Feb 17th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
ahanna,
Avalanche Canada
Human triggered avalanches are still possible, especially in deep wind-loaded pockets that overly a crust. Be ready to step back from sun exposed slopes if the sun is strong in the afternoon.
Summary
Confidence
Weather Forecast
Monday night: Scattered clouds with isolated flurries. Light to moderate northwest winds. Freezing level valley bottom.
Tuesday: Mix of sun and cloud. Light northwest winds. Freezing level 500 m.
Wednesday: Sunny. Light northwest winds. Freezing level 700 m.
Thursday: Sunny. Light southwest winds. Freezing level 1000 m.
Avalanche Summary
Natural activity over the last few days has been limited to small (mostly size 1) loose dry and thin slab avalanches out of steep headwalls, as well as a size 1.5 cornice triggered slab. A few skier triggered slabs have been reported, including this great MIN report of a skier triggered size 2 avalanche from an east/southeast facing feature at 2000 m on Sunday. Explosive control work conducted on Sunday and Monday produced slab and loose snow avalanches up to size 1.5.
Snowpack Summary
20-30 cm of snow from the past week has seen some redistribution in exposed alpine areas, with soft wind slabs forming in immediate lees of ridge crests. In sheltered areas, the recent snow is settling and may contain various sun crusts and layers of small surface hoar crystals.
A thick rain crust sits 30-60 cm below the surface, up to 2100 m. Recent reports indicate that faceting may be occurring at the interface of this crust and overlying snow in some areas. A weak layer sitting between a dense slab and a slick bed surface is a recipe for a future persistent avalanche problem.
The bottom 20 cm of the snowpack consists of basal facets and decomposing crusts that have not been an active avalanche problem since December, but could reemerge as a problem after sustained warming.
Terrain and Travel
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
- Extra caution is needed around cornices under the current conditions.
- Brief periods of sun could quickly initiate natural avalanche activity.
Problems
Storm Slabs
This problem will likely be focused in wind loaded lees of exposed terrain features. Fresh snow is likely to shed easily from steep slopes that see sun.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Natural cornice falls have been reported recently and will likely continue as the sun comes out over the next few days. Cornice falls are dangerous in their own right but they may also trigger avalanches on slopes they impact.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Feb 18th, 2020 5:00PM
