Avalanche Forecast
Issued: Feb 19th, 2012 9:19AM
The alpine rating is Persistent Slabs, Wind Slabs and Deep Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Intensity of incoming weather is uncertain on Tuesday
Weather Forecast
Monday: flurries bringing minimal accumulation of new snow. Light to moderate NW winds. Freezing level around 800 m. Tuesday: 5-10 cm new snow with winds increasing moderate to strong from the NW. Freezing level rising to 1000 m. Tuesday night into Wednesday: a slightly stronger band of moisture arrives bringing 10-15 cm new snow, freezing levels rising to 1500 m and strong westerly winds.
Avalanche Summary
Snow amounts over the early Feb weak layer reached threshold in many places on Saturday. Natural avalanches were observed in the storm snow to size 1.5. Avalanche control at Kootenay Pass produced avalanches up to size 2 running on a crust buried around 35 cm below the surface. Read the forecaster blog for further discussion on reaching the "tipping point".
Snowpack Summary
Saturday's storm brought around 15 cm new snow, bringing the gradually incrementing snow amounts above the early Feburary surface hoar layer to around 30 cm. Alpine winds have been strong enough to blow snow around and touchy wind slabs have formed predominantly on northerly and easterly aspects. The early February weak layer comprises large surface hoar on sheltered aspects, facets on northerly aspects and a crust on solar aspects. In shallow snowpack areas concerns remain for the mid-December persistent weakness down around 80-100cm and for basal facets. Treeline snowpack depths are approximately 230 cm.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 20th, 2012 9:00AM