Avalanche Forecast

Issued: Jan 1st, 2012 9:28AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Wind Slabs and Storm Slabs.

Avalanche Canada Jlammers, Avalanche Canada

Summary

Confidence

Fair - Freezing levels are uncertain on Monday

Weather Forecast

Monday: Heavy snowfall from Sunday night will extend into Monday morning. Expect strong southerly winds and freezing levels up to 700m.Tuesday: Moderate snowfall arriving late in the day, becoming very heavy overnight. Winds expected to be strong from the south. Freezing levels will start out at surface rising to 1000m as the precipitation intensifies.Wednesday: Heavy snowfall. Strong southerly winds and freezing levels at 1050m.

Avalanche Summary

A few natural size 1-1.5 windslabs were observed in the last 24 hours near Stewart.A natural size 1.5 was observed below treeline near Terrace.

Snowpack Summary

A relentless pummelling by snow, strong to extreme winds, and fluctuating freezing levels over the past week has added around 130cm of new snow near Terrace and around 75cm near Stewart. Strong south to southwest winds have created hard and soft wind slabs on lee slopes. Large sensitive cornices also exist. A 2-day break in the weather this weekend may have helped to strengthen the recently fallen snow, but only marginally. Expect further significant wind slab and storm slab development with the forecast weather.In the mid snowpack, buried surface hoar and a crust-facet combo (which extends up to alpine elevations in the south and to 1000m in the north) have become less of a concern in the Terrace area as test results show that they have gained significant strength. Although the probability of reactivity on these layers has decreased, the nature of any avalanche on these layers would be deep and highly destructive.The lower snowpack is generally well settled and strong.

Problems

Wind Slabs

An icon showing Wind Slabs
Deep wind slabs will continue to exist in exposed lee and cross-loaded terrain in the alpine and at treeline. Large, sensitive cornices are also a current concern above lee slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 4

Storm Slabs

An icon showing Storm Slabs
Deep and destructive storm slabs will continue to form on all aspects and elevations with forecast weather

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Valid until: Jan 2nd, 2012 8:00AM