Avalanche Forecast
Issued: Dec 23rd, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Persistent Slabs.
Stephen Holeczi,
Mount Dennis closed for avalanche control Thursday. No activities permitted. We are coming out of a recent avalanche cycle and the snowpack is still adjusting to the load. Good ski quality in sheltered locations.
Summary
Weather Forecast
Alpine winds from the West will stay elevated Thursday, and alpine temperatures will stay slightly warmer (-4 to -5C) than valley bottoms (-6 to -8C), No new snow is in the forecast until the weekend. Winds look like they will decrease Friday and Saturday.
Snowpack Summary
Winds from a variety of directions have blown the ~60cm of snow from the past week into wind slabs at higher elevations. The Dec 13 and Dec 7 sun crust/surface hoar/facet layers are down ~ 50cm and ~80 cm respectively. Height of snow at tree line is 80-150cm.
Avalanche Summary
Avalanche control Tuesday and Wednesday produced mixed results from no result to size 3. Most were storm slabs, sometimes stepping down to persistent layers. No new avalanches reported or observed in Little Yoho Wednesday.
Confidence
Problems
Wind Slabs
New wind slabs started to form Wed. and will continue to build Thurs. These are mainly found in the alpine but have been reported at treeline as well. The winds have been from many different directions so slabs may be found on a variety of aspects.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
There are a variety of weaker layers down ~50-80cm depending on the area. These are the Dec 7 and 13th layers of facets, suncrust, and isolated surface hoar. Their reactivity is a bit sporadic but treeline seems to be the biggest culprit.
- Dig down to find and test weak layers before committing to a line.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Valid until: Dec 24th, 2020 4:00PM
