Avalanche Forecast
Issued: Apr 20th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Wet, Cornices and Persistent Slabs.
Timothy Johnson,
Wednesday will be another warm day with freezing levels to 2500m. Start early and end early to avoid the heat of the heat of the day and rising avalanche danger.
Summary
Weather Forecast
Wednesday: A mix of sun and cloud with isolated flurries. Precipitation: Trace. Alpine temperature: High 2 C. Ridge wind W: 15-30 km/h. Freezing level: 2400 metres.
Thursday: Cloudy with sunny periods and isolated flurries. Precipitation: Trace. Alpine temperature: Low -13 C, High -6 C. Ridge wind NE: 10-30 km/h. Freezing level at valley bottom.
Snowpack Summary
Cold nights, helping the snowpack recovery and creating a supportive melt/freeze crust on all aspects and elevations. This crust will break down over the day, except above ~2500m where the snow is likely to remained dry for the near future. Weak faceted crystals at the bottom of the snowpack could be concern in shallow alpine snowpacks.
Avalanche Summary
A slower warming tread forecast through this week should allow for the snowpack to adjust. Sunny, exposed TL and BTL terrain rapidly losing coverage and the overall snowpack structure is weak and will collapse with very little load.
Confidence
Problems
Loose Wet
Start early to avoid this avalanche problem. Avoid steep, treed TL and BTL terrain in the heat of day; even cutting out a small wet slide can push you into a terrain trap.
- Use extra caution on solar slopes or if the snow is moist or wet.
- Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Cornices
Cornices are awake! These features are large, dense and heavy and will possibly trigger the deeper instability on the slope below. If you must travel near or below cornices, use good travel techniques and group management to reduce exposure.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
- Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Persistent Slabs
Shallow snowpack areas in the alpine have increased potential for human triggered and natural avalanches stepping to deeper layers.
- Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 21st, 2021 4:00PM
