Avalanche Forecast

Issued: Apr 16th, 2012 10:54AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Loose Wet, Wet Slabs and Persistent Slabs.

Avalanche Canada jfloyer, Avalanche Canada

Daily bulletins with danger ratings are finished for the season for this region. General advice can be found in the Avalanche Problems section and on the Forecast Details tab below. Additional information can be found in the Forecaster Blog.

Summary

Weather Forecast

Avalanche Summary

Spring conditions exist in the region. Avalanches are most likely to occur in response to solar radiation, warm temperatures, and periods of rain. Particularly dangerous conditions may develop during prolonged periods of warming, heavy rain, or on days with no overnight freeze. Under these conditions, surface avalanches may step down and trigger deeper wet slab avalanches. Prolonged warming may also weaken large and destructive cornices, which are a danger in themselves or could act as a heavy trigger on the slope below. Typically, avalanche activity ramps up during the day and is at a peak during the afternoon. If it's raining or there was no overnight freeze, avalanche activity can happen at any time.

Snowpack Summary

As we transition into spring the surface layers have a great deal of influence on the snowpack. When there is a solid re-frozen surface crust, travel is fast and easy, and the snowpack is held together by the surface cap. Any deeper persistent weak layers are unlikely to fail until the surface cap breaks down from daytime heating. During warm conditions, melt water is able to percolate within the snowpack and cause deeper weak layers to fail. If it cools off and snows, new snow may not bond well to the hard spring crusts, and isolated storm and wind slabs can easily develop.

Problems

Loose Wet

An icon showing Loose Wet
Moist or wet loose snow avalanches may release during periods of daytime warming or if periods of rain showers persist. Loose snow avalanches may trigger deeper weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Wet Slabs

An icon showing Wet Slabs
Large triggers like cornices or loose snow avalanches may propagate slides on the buried weak layer from March 27th. The likelihood may increase if there is no overnight freeze.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Persistent Slabs

An icon showing Persistent Slabs
Strong solar radiation or persistent warm temperatures may trigger deeply buried weak layers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 7

Valid until: Apr 17th, 2012 9:00AM