Avalanche Forecast

Issued: Mar 13th, 2015 9:33AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Cornices.

bcorrigan, Avalanche Canada

South Coast.

New snow, rising temperatures and strong winds make perfect conditions for avalanches !

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

On Saturday we are expecting 10 to 20mm of moisture with freezing levels dropping to 1000m by Sunday morning. Sunday and Monday will see another 10 to 20mm with freezing levels around 1200m. Moderate to strong winds above 1500m will accompany this system.

Avalanche Summary

One report from yesterday of a natural wind slab avalanche, size 2, on a North East aspect, wind-loaded at 2000m. A few wet snow avalanches have been reported occurring on solar aspects. Cloudy skies may keep the surface from overnight freezing and rising temperatures may increase the likelihood of loose wet avalanches and cornice failures.

Snowpack Summary

Incoming precipitation will fall on a variety of old snow surfaces that exist throughout the region. There are numerous crusts and old wind slabs buried in the snowpack above treeline that may still be problematic. Below treeline the snowpack has had numerous warming and rain events and should be bombproof for the most part. Rain has recently been reported to ridge tops in the Coquihalla region. Solar aspects are reported to be going isothermal in some areas below 1600m

Problems

Wind Slabs

New snow with strong winds will build fresh wind slabs on lee slopes, adding load to the existing slab problems

The new snow will require several days to settle and stabilize.>Assess start zones carefully and use safe travel techniques.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Cornices

With warm temperatures and additional loads we should be seeing cornice failures.

Cornices become weak with daytime heating, so travel early on exposed slopes.>Stay well back from cornices.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East, South East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Mar 14th, 2015 2:00PM