Avalanche Forecast

Issued: Apr 11th, 2014 9:44AM

The alpine rating is moderate, the treeline rating is low, and the below treeline rating is low. Known problems include Loose Wet, Cornices and Deep Persistent Slabs.

jlammers, Avalanche Canada

Sea To Sky.

Avalanche danger can rise very quickly with warming and solar radiation. Be aware of changing conditions and overhead hazards. Terrain choices and timing can be critical.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Saturday

Weather Forecast

Overview: A ridge of high pressure will dominate the coast by Saturday morning bringing mainly sunny skies and rising freezing levels for the forecast period.Saturday: Mostly clear skies / Moderate northerly winds / Freezing level at about 1600mSunday: Clear skies / Light northerly winds / Freezing level at about 1700mMonday: Mostly clear skies with increased cloud late in the day / Light southwest winds / Freezing level rising to about 2600m

Avalanche Summary

Cornices have started to fail with warmer temperatures and sunny skies up to size 2-2.5, without pulling deeper slabs on the slopes below. Numerous loose wet avalanches have occurred up to size 2 on steeper solar aspects.

Snowpack Summary

A melt-freeze crust exists on all aspects up to 2200 m, and dryer snow can be found on high northerly aspects. The recent warmer temperatures have helped to strengthen and settle the upper snowpack, especially on solar aspects. Isolated wind slabs have formed and are sensitive to rider triggers, especially on slopes with a buried crust. Large sagging cornices are looming over slopes and pose a threat, especially when the sun comes out.The early February facet/crust layer is now down close to 200 cm. This layer is largely dormant at this time; however, it should remain on your radar as we transition into a warm-up with minimal overnight refreeze and intense solar output.

Problems

Loose Wet

Watch for loose wet avalanches with daytime warming on steep, sun-exposed slopes. Loose wet avalanches can be pushy and entrain mass quickly.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Watch for clues and avoid slopes if you start to see pinwheels, moist and/ or wet snow surfaces and natural avalanche activity.>

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Cornices

With forecast warming and intense solar radiation the likelihood of triggering a large cornice fall will increase dramatically. A cornice fall may also be what it takes to "wake-up" deep and destructive weaknesses which formed earlier in the season.

Pay attention to overhead hazards like cornices.>Cornices become weak with daytime heating. >

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Deep Persistent Slabs

Although unlikely, deep persistent avalanches would be very large and highly destructive. Possible triggers include cornice fall, a surface avalanche in motion, warming and intense solar radiation.

Be aware of the potential for large, deep avalanches due to the presence of buried weak layers.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

3 - 6

Valid until: Apr 12th, 2014 2:00PM