Avalanche Forecast

Issued: Apr 12th, 2014 9:18AM

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. For more insight into spring messaging, check out our latest Blog Post.

Summary

Confidence

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

Weather Forecast

Sunday: Clear skies / Light and variable winds / Freezing level at about 2200mMonday: Clear with increased cloud late in the day / Light to moderate southwest winds / Freezing level at about 2200mTuesday: Overcast skies with very light precipitation / Light westerly winds / Freezing level at about 1500m

Avalanche Summary

On Saturday a few cornice collapses were reported including a size 3 release on Forger Peak in Garibaldi Park. It is unclear if the cornice release triggered a slab on the slope below. I would expect continued loose wet activity and cornice fall with continued daytime warming on Saturday.

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 exist, although they are likely settling and gaining strength. 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.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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.

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

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.

Likelihood

Unlikely

Expected Size

3 - 6

Valid until: Apr 13th, 2014 2:00PM