Avalanche Forecast
Issued: Dec 19th, 2019 4:09PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Deep Persistent Slabs and Storm Slabs.
Benjamin Firth,
Parks Canada
Significant amounts of wind and precipitation forecasted for Friday and Saturday. As the precipitation falls the hazard will rise. Expect Highway 93N to be closed Sunday. Ice climbs Weeping Wall and Polar Circus will be closed Saturday and Sunday.
Summary
Weather Forecast
"Atmospheric river" setting up to bring moist warm air from the southwest starting early friday morning and persisting through Saturday night. This system will bring moderate to strong south west winds and significant amounts of precipitation. Freezing levels could rise to 1600 meters on Friday.
Snowpack Summary
Moderate to strong SW ridge winds continue building varied strength windslabs on lee and crossloaded features at or above treeline. Persistent interfaces layered through the snowpack that might wake as the up to as the 25cm's of new snow forecasted in the next 24 hours accumulates.
Avalanche Summary
A skier accidental size 1 wind slab in an alpine feature was reported today on the south west side of Hilda Ridge. No other avalanches observed on Thursday. Expect to see more avalanche activity Friday and through the weekend.
Confidence
Problems
Wind Slabs
Strong SW winds are creating wind slabs in NW to SE lee aspects. Sensitivity expected to be reactive in the immediate future and may wake deeper, weaker interfaces.
- Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A few large avalanches were observed during last cycle early in December and we suspect it was on this layer. Triggering the windslab problem has potential to release this lower problem layer.
- If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
As new snow accumulates, the hazard will increase.
- Minimize exposure during periods of heavy loading from new snow and wind.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 20th, 2019 4:00PM
