Avalanche Forecast

Issued: Mar 13th, 2015 9:29AM

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

Sea To Sky.

Recent additional load to the wind slabs and cornices require careful route finding and decision making.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Saturday will see more precipitation with a possibility of 10 15 cm at upper elevations and rain below 1500m. Sunday should be clear with freezing levels dropping to 1000m then slowly rising as another wave of moisture arrives on the coast. Winds will be light to moderate at ridge tops.

Avalanche Summary

Numerous explosive triggered avalanches to size 1.5 reported yesterday as well as one 1.5 skier accidental on a wind slab. Forecast sunny skies may increase the likelihood of loose wet avalanches on solar aspects, and with recent warm temperatures, cornice failures should be on the "lookout list".

Snowpack Summary

Melt-freeze crusts can be found on solar aspects in the alpine, and on all aspects at lower elevations. On high north-facing terrain, old wind slabs and surface facets still exist. The snowpack is generally strong and well settled. However, be aware that cornices may become weak with daytime warming. and incoming precipitation will develop wind slabs on lee slopes.

Problems

Wind Slabs

New snow with warm temperatures and wind make the perfect combination for wind slab formation and avalanches, use extreme caution on lee slopes.

Be careful with wind loaded pockets while approaching and climbing ice routes.>Avoid cross loaded slopes at or above treeline.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Warm temperatures and additional load are prime conditions for cornice failures.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Stay well back from cornices.>Cornices become weak with daytime heating, so travel early on exposed slopes.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

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