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
Watch for freshly formed wind slab in the alpine as you transition over convex roll features or just below ridgetop.
Expect the upper snowpack to become unconsolidated during daytime warming and allow for even small avalanches to gain enough mass to become hazardous.
Summary
Confidence
Avalanche Summary
No new avalanches were reported in the region on Thursday.
On Wednesday a large (size 2.5) skier trigger avalanche was reported west of the town of Fernie. This avalanche initiated near 1700 m on a south aspect and ran approximately 700 m. Initially the avalanche was a slab and then began to entrain the available storm snow in the track with debris photos reminiscent of a wet loose avalanche. See this MIN report link for further information.
We expect backcountry users will see evidence of a small dry loose avalanche cycle in the alpine from convective flurries through the last few days.
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
Snowpack Summary
In the alpine and around treeline, 10-30 cm of recent snow covers a frozen melt freeze crust.
Below treeline, expect to find moist or refrozen surfaces, and a shrinking snowpack that is isothermal during the heat of the day.
The mid snowpack is generally settled and strong, except in areas with snow depths less than 150 cm. In these lower snow areas, the mid-pack is likely weaker and more faceted.
The lower snowpack includes a layer of weak sugary crystals near the ground. This layer has shown signs of gaining strength, and it has not produced recent avalanche activity in this area.
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 carefull around freshly wind loaded features.
- Be alert to conditions that change with elevation and sun exposure.
Problems
Storm Slabs
Investigate the bond of recent snow to surfaces below. Use caution when transitioning into steep slopes where wind has likely created new windslabs.
You are most likely to find reactive storm slabs close to the continental divide where snowfall amounts through the last few days were higher.
Aspects: All aspects.
Elevations: Alpine.
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
