Avalanche Forecast

Issued: Dec 4th, 2014 7:53AM

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.

Avalanche Canada Peter, Avalanche Canada

Expect a big difference in precipitation amounts and temperatures from Howe Sound (warm and wet) up to Whistler (not quite as warm or wet). Regional conditions could vary quite a bit this weekend.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Friday: Cloudy with showers or flurries (trace to 5mm). The freezing level is 1800-2000 m. Ridge winds are 30 gusting to 50 km/h from the south. Saturday: Periods of rain of snow (10-20 mm). The freezing level should drop from 2100 to 1600 m. Winds ease to light from the southwest. Sunday: Probably a drier day. Freezing levels should jump up to 2000-2200 m. Winds are moderate from the south.

Avalanche Summary

There was one report of an avalanche that released from a rocky sun-exposed slope near Whistler on Tuesday, but details on this slide are limited. No other avalanches have been reported.

Snowpack Summary

The current snow surface is highly variable with surface hoar or facetted snow reported in sheltered areas, and pockets of wind slab or a crust (from last weeks rain) in open wind-exposed terrain. Recent cold temperatures have created a strong temperature gradient in the upper snowpack resulting in facetting of the most recent snow. Winds during the past week have been variable and have blown snow into dense wind slabs on a variety of aspects or has cross-loaded gulley features. A solid rain crust is buried 10-20 cm deep at and below treeline. Another crust that was buried in mid-November is down 40-60 cm. The snow pack depth drops significantly below treeline with essentially no snow below 1600 m.

Problems

Wind Slabs

An icon showing Wind Slabs
New wind slabs may form on north to east facing slopes. These wind slabs may be sitting on a slick crust from last weeks rain and may not bond well. Old hard wind slabs may also be lurking on west or south facing slopes. 
Avoid travelling in areas that have been reverse loaded by winds during the most recent dry spell.>Be alert to conditions that change with elevation.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs
Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Dec 5th, 2014 2:00PM