Avalanche Forecast

Issued: Feb 15th, 2015 7:11AM

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

pgoddard, Avalanche Canada

South Columbia.

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Summary

Confidence

Fair - Freezing levels are uncertain on Wednesday

Weather Forecast

Monday, Tuesday and Wednesday are expected to be dry and cool, with sunny periods. Winds are generally light from the NW. The freezing level is at valley floor by night and rising to around 1200 m by day. The next storm system may arrive on Wednesday with warming temperatures and light precipitation, but weather models are not in agreement about this.

Avalanche Summary

Several size 1.5-3 avalanches were triggered naturally over the last few days in response to storm loading, wind and warm temperatures. A number of cornice collapses and an ice fall have also been reported. Skiers triggered a very large (size 3.5) persistent slab on Thursday on a NE aspect in the alpine in the Monashees. It failed on the late-Jan layer. Now that temperatures have cooled, avalanche activity is likely to ease, although direct sun may spark a new avalanche cycle on steep slopes or cause more cornices to fall.

Snowpack Summary

Now that the weather has finally cooled after ten days of very warm temperatures and bursts of rain, surface crusts have formed to at least 2000 m. Underneath newly formed crusts, you may find moist snow for a few days yet. At alpine elevations, new wind slabs or storm slabs may be found. Cornices are large and weak. The late-Jan crust/surface hoar layer, buried up to a metre deep, continues to give sudden results in snowpack tests in some locations. The mid-January surface hoar is typically down 80-120cm. Chances of triggering this have decreased, but it could possibly be triggered from thin or rocky snowpack areas; or perhaps with a cornice fall, or an avalanche stepping down.

Problems

Wind Slabs

Wind slabs may be lurking on lee and cross-loaded features in the alpine. Cornices are weak and may collapse.

Be cautious as you transition into wind affected terrain.>Avoid steep slopes below cornices.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Persistent slabs are most likely to be triggered from thin snowpack areas, or with large triggers like cornice fall or an avalanche stepping down.

Avoid common trigger points like convexities or areas with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 16th, 2015 2:00PM