Archived

Avalanche Forecast

Jan 31st, 2012–Feb 1st, 2012

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

4: High

The avalanche danger rating at treeline will be high

Below Treeline

3: Considerable

The avalanche danger rating below treeline will be considerable

Alpine

4: High

The avalanche danger rating in the alpine will be high

Treeline

3: Considerable

The avalanche danger rating at treeline will be considerable

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Northwest Coastal.

Confidence

Fair - Due to limited field observations for the entire period

Weather Forecast

Wednesday: Flurries are expected in the morning increasing to heavy precipitation and strong southwestely in the evening. Freezing levels are expected to remain around 1200m. Thursday: Heavy precipitation with 50mm expected throughout the day. Extreme southerly winds and freezing levels as high as 1400m. Friday: Precipitation and wind should ease off with a clearing and cooling trend throughout the day.

Avalanche Summary

Warm temperatures and light to moderate precipitation resulted in several low-elevation natural storm slab avalanches up to Size 1.5 on Monday. Storm slabs continue to be reactive to natural and human triggers.

Snowpack Summary

Total snowpack depths are well above average for this time of year and it won't stop snowing! Recent warm temperatures and upside-down storms created a touchy surface slab. Other weaknesses within and under the 150+cm of recent storm snow create the potential for 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 avalanche stepping-down could reawaken deeper persistent weaknesses.

Avalanche Problems

Wind Slabs

Widespread due to strong, shifting winds and large amounts of snow available for transport, but are generally lurking below ridgecrests, behind terrain features and in cross-loaded gullies. They can fail as very large, destructive avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 6

Storm Slabs

Large storm slab avalanches have been occurring for the past week and are expected to remain sensitive to triggers for the forecast period.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 1 - 5