Avalanche Forecast
Issued: Feb 16th, 2021 5:06PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Persistent Slabs.
Lisa Paulson,
We have observed several cornice failures over the last few days. The recent cold snap has facetted and weakened them. Some of these failures have triggered slabs on the slopes below, others have not.
Give cornices an even wider berth than normal.
Summary
Weather Forecast
A few flurries & increased wind Tuesday night tapering by morning. For Wednesday, highs will be in the around -12C with light W-NW winds and a mix of sun & cloud. Thursday night will be clear and cold with lows in the -25 range and daytime highs -10 to -15. Temperatures will warmer through the weekend with flurries on Monday.
Snowpack Summary
Wind effect in the alpine with small isolated wind slabs. In sheltered areas, the surface snow is facetted and is sluffing more easily in steep terrain (40 degree). A facet layer from Jan 27th is present at treeline and in the alpine down 30-40. On steep south this layer may consist of a thin sun crust as well.
Avalanche Summary
Several cornice failures have been observed over the past few days including one on Fatigue Mountain on Sunday that triggered a size 3 to ground reminding us that there is still a deep layer. Forecasters ski cut a size 2 in the Simpson area at 2100 m on the persistent layer Saturday. SSV reports working with small stubborn windslabs in the alpine
Confidence
Problems
Wind Slabs
Recent variable winds have built slabs. These are mainly small in size but would be of concern in steep alpine terrain. There have also been several examples of cornice failures over the last few days creating larger events that involve these slabs.
- Use caution in lee areas. Recent wind loading has created wind slabs.
- Pay attention to overhead hazards like cornices which could trigger slabs.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Loose Dry
The past week of cold temperatures has weakened the surface snow to where it sluffs easily in steep (40 degree) terrain. This is mostly a problem in narrow confined terrain like gullies or couloirs with a continuous steep incline.
- On steep slopes, pull over periodically or cut into a new line to manage sluffing.
- Consider that avalanches may run further than expected as they entrain this loose surface snow.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Persistent Slabs
Sporadic observations of avalanches over the last two weeks, mainly centered around the Kootenay region. These are 30-40 cm soft slabs over the Jan. 27 layer : facets, or facets over a thin sun crust on steep south aspects
- Consider that avalanches may run further than expected as they entrain this loose surface snow.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 17th, 2021 4:00PM
