Avalanche Forecast

Issued: Feb 10th, 2015 9:08AM

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

Avalanche Canada esharp, Avalanche Canada

Another pulse of new snow will be accompanied by strong to extreme winds re-elevating avalanche hazard.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain

Weather Forecast

A trough of warm air aloft will linger over the region Wednesday before a series of fronts hits the North Coast forcing the arctic air to retreat north. Wednesday will see 5-20cm of new snow accompanied by strong to extreme southerly winds. An above freezing level may mean freezing rain for lower elevations. Snow will continue through the rest of the forecast period with another 10-20cm on Thursday, and 5-15cm on Friday. Winds will remain strong from the south. Freezing levels will climb through the week reaching 2000m by Friday.

Avalanche Summary

Loose natural avalanches are being reported from steep terrain. While natural slab avalanches appear to becoming less frequent avalanche control on Monday produced slab avalanches up to size 3 on virtually all aspects and elevations. It sounds like a lot of these avalanches ran on mid storm instabilities although some larger results observed on South facing slopes released on the late January crust. Glide cracks were reported from the Shames backcountry on Monday.

Snowpack Summary

A new layer of surface hoar was reported to be developing across the region above the 50 to 100cm of snow that fell during last weeks pineapple express. The storm also brought screaming winds out of the E through SE that formed windslabs in lee features. The late-January crust is thought to be down 50 to 130cm in the south of the region and about half this depth in the north. This crust may have surface hoar on it. The mid-January rain crust and/or surface hoar layer is down over 150cm in the south and has generally become inactive although it may still be a concern in thinner snowpack areas. The November crust/facet combo near the bottom of the snowpack is thought to be generally well bonded but may still be reactive in the far north of the region.

Problems

Storm Slabs

An icon showing Storm Slabs
New snow will fall on surface hoar in many locations. Forecast southerly winds of up to 100km/h will rapidly load lee features. The new snow may also stress older storm instabilities that have not yet had a chance to fully stabilize.
The new snow will require several days to settle and stabilize.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Persistent Slabs

An icon showing Persistent Slabs
Several weak layers are lucking in the snowpack and slopes at and above treeline still may have the potential to produce a very large and destructive avalanches. Smaller surface avalanches may step down to these deeper instabilities.
Be aware of the potential for large, deep avalanches due to the presence of buried crusts and/or surface hoar.>Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

4 - 8

Valid until: Feb 11th, 2015 2:00PM