Avalanche Forecast

Issued: Feb 10th, 2013 8:08AM

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

Avalanche Canada swerner, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Monday: The pattern and flow starts changing today as the ridge move southward and a zonal flow sets up. An embedded cold front will move through the region bringing moderate NW winds and a trace of snow. Treeline temperatures will sit near -5 and freezing levels will be around 1800 m. Tuesday: The fast paced zonal flow will continue with a trough moving in from the West bringing moderate-strong NW winds and light snow accumulations. Treeline temperatures will be near -8 and freezing levels around 1800 m.Wednesday: Another ridge is building bringing dryer conditions, especially for the short term. Ridgetop winds will be light from the West. Treeline temperatures -10 and freezing levels falling to valley bottom. 

Avalanche Summary

No new natural avalanche observations reported. On Saturday, the only notable events occurred in the Lizard Range with a couple skier triggered wind slabs size 1-1.5, the crown depth was 20-30 deep and 15-20 m wide. Slab showed decent propagation. There were also a few size 1 loose snow avalanches were reported running out of steep terrain.

Snowpack Summary

Up to 15 cm of recent snowfall has been redistributed into dense or hard wind slabs at higher elevations from variable winds. A hard sun crust is likely on steep solar aspects. The new storm snow overlies old wind slabs in exposed areas, settled storm snow or spotty surface hoar in more sheltered terrain, and a crust on previously sun-exposed slopes. A variable interface (surface hoar/facets/sun crust) was buried on Jan 23 and is down about 20-40cm. In most locations it now appears to be well bonded. The lower snowpack is generally well-settled.Cornices in the region are reported to be well developed and loom over heavily used slopes.

Problems

Wind Slabs

An icon showing Wind Slabs
Pockets of wind slab are likely to exist at higher elevations on a variety of aspects and may react to the weight of a skier/rider. Steep sheltered terrain could see loose dry or wet snow avalanches depending on aspect.
Highmark or enter your line well below ridge crests to avoid wind loaded pillows.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Cornices

An icon showing Cornices
Large and potentially weak cornices loom over open slopes and may fail with daytime warming and/or solar radiation.
Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Feb 11th, 2013 2:00PM