Avalanche Forecast

Issued: Apr 15th, 2012 10:31AM

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

jlammers, Avalanche Canada

South Columbia.

Summary

Confidence

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

Weather Forecast

Monday: clear conditions in the morning with light snowfall developing by mid-day and intensifying slightly overnight / moderate southwest winds / freezing level at 1900m Tuesday: broken cloud / light to moderate westerly winds / freezing level at 1800m Wednesday: light snowfall / light southwest winds / freezing level at 1600m

Avalanche Summary

No new avalanches were reported form the region, but that may be attributed to the lack of observations. In a neighboring region glide crack releases to size 3 were observed at lower elevations while new storm slabs to size 1 were observed above 2000m.

Snowpack Summary

Last week, very warm temperatures affected all but the highest north facing slopes. Since Thursday morning, light to locally moderate amounts of new snow have formed soft slabs on the resulting crust at treeline and above while rain has continued to penetrate and weaken the snowpack at lower elevations. Up to 80cm below the surface, you'll find another crust that was reactive last week in the alpine and at treeline. The mid-February buried surface hoar layer is down about 140-220 cm, although avalanches releasing on this layer represent an extremely low probability-high consequence scenario. Cornices in the region are very large. With spring temperatures, these are more likely to become weak and fail. They could provide a large enough trigger to release deep layers on slopes below.

Problems

Loose Wet

Forecast sun and spring temperatures will promote ongoing loose wet avalanche activity, particularly in steep terrain. Loose wet avalanches can be heavy and entrain mass quickly.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Wet Slabs

Buried crusts will provide an ideal sliding layer for wet slabs, especially on sun-exposed slopes or with warmer temperatures at lower elevations. Destructive glide cracks are also releasing regularly at this time.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 5

Wind Slabs

New wind slabs exist in alpine terrain in some parts of the region. Watch for triggering in unsupported lee terrain.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Apr 16th, 2012 9:00AM