Avalanche Forecast
Issued: Nov 21st, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
IJ,
Avalanche Canada
Temperatures, winds and up to 5 cm of new snow are forecast to fall Wednesday and we expect this to lower the avalanche danger.
Early Season Conditions means high variability right now. Some places are below threshold to avalanche, but if there is snow, be wary!
Summary
Confidence
Avalanche Summary
Several avalanches up to size 2 were observed on Tuesday in the Bow Summit area. These were on both solar and shaded aspects and likely both cornice and temperature triggered.
In other areas, several wind triggered avalanche up to size 1.5 were observed in extreme alpine terrain.
Snowpack Summary
Recent strong to extreme winds have left alpine and treeline areas heavily scoured. Snowpack depths range from 30-50 cm at treeline and 40-80 cm in the alpine with deeper pockets of wind deposited snow in lee areas. A melt-freeze crust has formed on the surface from recent solar input on south and west aspects. The bottom of the snowpack consists of a buried crust and facets.
Weather Summary
An upper disturbance will bring snow on Wednesday. Only a few cms are expected along the divide and to the west but up to 5 cm may fall around the Banff townsite and possibly more to the east
Freezing levels are forecast to drop to valley bottom and winds die to light from the N
Thursday into Friday, a ridge sets up with dry, clear and calm conditions
Terrain and Travel Advice
- Ice climbers should be equipped with avalanche safety gear.
- Early season avalanches at any elevation have the potential to be particularly dangerous due to obstacles that are exposed or just below the surface.
Problems
Persistent Slabs
Many places with enough snow to avalanche have a weak layer of facets and/or a melt freeze crust at the base of the snowpack. This weak layer will likely become less sensitive as the temperatures drop and the winds ease on Wednesday.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 22nd, 2023 4:00PM
