Avalanche Forecast

Issued: Feb 28th, 2015 7:30AM

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

triley, Avalanche Canada

Purcells.

New snow, northerly winds and cold arctic air are expected to increase the avalanche danger on Monday. Are you a member of Avalanche Canada? Join today at avalanche.ca/membership

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Cloud developing overnight combined with light southerly winds and freezing levels down to valley bottoms, and alpine temperatures around -15. Mostly cloudy on Sunday with light southwest winds and freezing levels rising up to about 1000 metres. Precipitation starting early Monday morning as cold arctic air descends from the northeast and collides with warmer moist air from the Pacific. Most areas are expected to see 5-10 cm of new snow, some areas in the south and east of the region may see enhanced snowfall.

Avalanche Summary

A small size 1.0 pocket of windslab was triggered accidentally by a skier on a northeast aspect in the alpine.

Snowpack Summary

Variable amounts of dry facetted surface snow and pockets of surface hoar can be found above the mid-February crust. New melt-freeze crusts can be found on solar aspects at all elevations. The mid-pack is well settled. The late-Jan crust/surface hoar layer can be found about a metre below the surface in deeper snowpack areas. The mid-January surface hoar, can be found below that. These layers have gained significant strength, and chances of triggering these weaknesses have decreased dramatically. However, triggering may be possible with a large input such as cornice fall, or an avalanche stepping down, especially on slopes that see a lot of sun.

Problems

Persistent Slabs

Triggering persistent slab avalanches has become unlikely, but may be possible with large loads like cornice falls. Periods of strong solar radiation may allow for triggering from weak thin snowpack areas.

Conditions have greatly improved, but be mindful that deep instabilities are still present.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

3 - 5

Wind Slabs

Northerly winds may develop pockets of windslab in the alpine.

Avoid freshly wind loaded features.>Avoid travelling in areas that have been reverse loaded by winds.>

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Mar 1st, 2015 2:00PM