Avalanche Forecast

Issued: Feb 4th, 2012 9:35AM

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

pgoddard, Avalanche Canada

Northwest Coastal.

Avalanche danger will peak during the heat of the day.

Summary

Confidence

Fair - Freezing levels are uncertain on Sunday

Weather Forecast

The next few days should bring generally benign weather, except on Sunday when a weak disturbance will bring very light snow to the area. Otherwise, expect no precipitation, light winds, cool nights and warm days.

Avalanche Summary

On Friday, slab avalanches up to size 3.5 were reported in response initially to rain and then during the day to intense solar radiation. On Thursday, numerous large (up to size 3) slab avalanches were reported out of lee terrain (SW predominantly) along Bear Pass during the warming period as the snow turned to rain. Lower elevations were especially active.

Snowpack Summary

Total snowpack depths pushing 5m at treeline are at new record levels for this time of year. Recent warm temperatures helped settle storm snow into a touchy surface slab at lower elevations. Other weaknesses can be found within the upper snowpack and the Jan. 20th facets down around 150cm. These create the potential for large step-down avalanches, but things seem to be settling rapidly. Strong winds associated with recent storms means large weak wind slabs and cornices on lee and cross-loaded terrain. Most snowpack concerns are limited to the surface layers. However, large triggers such as cornice falls and smaller avalanches stepping-down could affect deeper weaknesses.

Problems

Storm Slabs

Avalanche activity recently spiked in response to warming. Cooler temperatures and cloud cover should decrease this problem on Sunday, but expect storm slabs to become touchy again by Monday.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Persistent Slabs

Recent rain and warm temperatures promoted avalanche activity at low elevations on a layer of facets buried around 20th Jan. This problem may creep higher in elevation with continued warm alpine temperatures.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 6

Cornices

Cornices will be weakest during warm and sunny periods. Cornice fall could trigger an avalanche on the slope below.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

3 - 7

Valid until: Feb 5th, 2012 3:00AM