Avalanche Forecast
Issued: Apr 20th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Loose Dry.
jpercival,
Avalanche Canada
Dangerous avalanche conditions exist in the alpine where 20-40 cm of storm snow and northwesterly winds have created fresh storm slabs.
Use caution in wind loaded areas where storm slabs are deeper, more cohesive, and are most likely to be reactive to human triggering.
Summary
Confidence
Avalanche Summary
No new avalanches were reported in the region on Thursday.
On Tuesday, a widespread natural dry loose avalanche cycle was observed, up to size 1.5. Avalanches primarily initiated in steep alpine terrain.
If you have any observations from this region, let us know what you are seeing by submitting a report to the Mountain Information Network.
Snowpack Summary
In the alpine and at treeline, 20-40 cm of storm snow is rapidly settling with daytime warming. Down 20-50 cm a thick melt freeze crust is found up to 2200 m.
The mid snowpack is generally settled and strong at treeline and above.
A weak layer of large, sugary crystals persists at the base of the snowpack. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.
Weather Summary
Thursday Night
Cloudy with isolated flurries, 1-5 cm accumulation. Light southwest ridgetop winds. Freezing levels 500 m. Treeline low around -9 °C.
Friday
Mainly cloudy with isolated flurries, trace accumulations. Light to moderate northwest ridgetop wind. Freezing levels 1600 m. Treeline high around -1 °C.
Saturday
Mix of sun and cloud with isolated flurries, trace accumulations. Light to moderate west ridgetop wind. Freezing levels rise from valley bottom to 2000 m by mid-day. Treeline high 0 °C.
Sunday
Mostly cloudy with sunny periods and isolated flurries, trace accumulations. Moderate west ridgetop wind. Freezing levels rise from 700 m bottom to 2100 m by mid-day. Treeline high +2 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Brief periods of sun could quickly initiate natural avalanche activity.
- Be especially cautious as you transition into wind affected terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
Problems
Storm Slabs
20-40 cm of storm snow and warm temperatures have formed cohesive slabs at higher elevations. Slabs are likely most reactive to human triggering on lee slopes where northwest winds have built deeper pockets of slab.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Be alert to changing conditions when daytime heating and direct sun are impacting slopes. Rocks will heat up with daytime warming and may become trigger points for loose avalanches.
Aspects: South East, South, South West, West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 21st, 2023 4:00PM
