Avalanche Forecast
Issued: Apr 16th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
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Avalanche Canada
Good riding can still be found on high elevation shady terrain. Watch for wind slabs and, if more than 15 cm of new snow falls then storm slabs too. Monday danger ratings are based on a forecast of 15 cm of new snow. If where you ride more than 20 - 25 cm of new snow arrives increase the local Danger Rating to CONSIDERABLE.
The field data upon which we build this forecast are limited; please assess conditions as you travel and adjust your objectives, terrain choices, and travel techniques to match the conditions encountered.
Summary
Confidence
Moderate
Avalanche Summary
No avalanche reports were received Saturday.
Friday's reports spoke to further evidence of Wednesday's widespread natural wind slab (up to size 3) and wet loose avalanche cycle. Explosive tests on cornices and north facing terrain released up to size 2 slabs in the storm snow. A few natural size 2 slabs were reported running on the April 1 melt-freeze crust.
Snowpack Summary
Daytime convective clouds continued to bring snow, mainly in the Cariboos and primarily at alpine elevations. On north aspects above 1600 m, recent but settling snow overlies old, faceted grains, now around 30-70 cm deep.
On solar aspects to mountaintop, and north aspects to around 2000m the recent snow either overlies a widespread melt-freeze crust or there is a crust at the surface. Solar aspects becoming moist in the afternoon, as are all aspects at lower elevations (around 1700 or 1800 m).
The middle of the snowpack is generally well-settled and strong. A weak layer of facets at the base of the snowpack remains a concern, primarily in alpine terrain shallow or variable (thick and thin) snowpack depths.
Weather Summary
Sunday Night
Cloudy with periods of snow; accumulations around 5 - 10 cm. Freezing level around 1000 m. Wind moderate from southwest, gusting to strong.
Monday
A mix of sun and cloud. Flurries with only an additional 1 to 3 cm accumulating. Freezing level climbs to around 1500 m and alpine temperatures around zero to -5 C. Light to moderate southwest winds.
Tuesday
A mix of sun and cloud with isolated flurries. Only a trace of new snow. Freezing level climbs to around 1800 m and alpine temperatures around zero to - 5 C. Light, gusting to moderate southwest winds.
Wednesday
Cloudy with sunny periods and isolated flurries. Nil to 5 cm of snow. Freezing level climbs to around 1700 m. Alpine temperatures zero to -8 C. Light southerly wind.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
- Be alert to conditions that change with elevation and sun exposure.
- Expect slab conditions to change drastically as you move into wind exposed terrain.
- Minimize overhead exposure; avalanches triggered by warming or cornice fall may be large and destructive.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Wind Slabs
There's not enough new snow in the forecast to suggest a widespread storm slab problem. However, combined with wind, anticipate fresh wind slab development. Watch for these wind slab pockets in steep north and east-facing leeward slopes.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. Thinner snowpack areas and areas with variable thick and thin coverage at alpine elevations is where this problem is most likely found. April's warming temperatures may gradually increase the sensitivity of this layer, especially in thin snowpack areas.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 17th, 2023 4:00PM
