Avalanche Forecast
Issued: Nov 26th, 2021 4:00PM
The alpine rating is Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeForecast new snow throughout the day on Saturday and extreme southwesterly winds will form fresh storm slabs reactive to human triggers. These slabs will be especially reactive on lee features at treeline and above.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
FRIDAY NIGHT: Clearing skies / Strong, southwesterly winds / Low of -10 / Freezing level surface.
SATURDAY: Snow/rain; 10-20 cm / Extreme, southwesterly winds / High of -2 / Freezing level rising to 1300 m.
SUNDAY: Snow/rain; 10-20 cm / Strong, southwesterly winds / High of -1 / Freezing level 1000 m
MONDAY: Mix of sun and cloud / Light, westerly winds / High of -6 / Freezing level surface.
Avalanche Summary
Several large, natural storm slab avalanches up to size 3 were reported on west and northwest aspects in the alpine on Thursday.Â
Snowpack Summary
20-30 cm of recent snow at upper elevations and strong southerly winds have created fresh storm slabs reactive to human triggers.
At treeline and below, the snow was likely moist and has formed a surface crust.
A crust formed in early November has been reported down 80-120 cm. There has been some evidence of large avalanches running on this crust. This will be a layer to monitor throughout the season.
Terrain and Travel
- Give the new snow time to settle and stabilize before pushing into bigger terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Be especially cautious as you transition into wind affected terrain.
- Avoid freshly wind loaded terrain features.
- Remember that the snowpack will be significantly different at higher elevations than lower down.
Problems
Storm Slabs
Storm slabs are expected to remain reactive to human triggers, especially on lee features at treeline and above.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 27th, 2021 4:00PM