Avalanche Forecast

Issued: Feb 13th, 2012 8:28AM

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

Avalanche Canada jfloyer, Avalanche Canada

Summary

Confidence

Good - -1

Weather Forecast

Tuesday: Light snowfall starting around midday. Accumulations shouldn't be greater than 5 cm. Winds light from the southwest. Freezing level around 800 m. Wednesday: A ridge of high pressure forms, which is associated with a short-lived incursion of cold, northerly air. Expect some good periods of sunshine. Morning temperatures will be around -10C, but temperatures will rise rapidly during the day, with afternoon freezing levels peaking at around 1000 m. Thursday: A weak frontal system moves in bringing around 5 cm new snow and elevating freezing levels slightly to around 1200 m.

Avalanche Summary

No new avalanches have been reported in this region recently.

Snowpack Summary

Generally light snowfall has buried an assortment of old snow surfaces including crusts, old wind slabs, surface hoar and surface facets. The crusts have formed on all aspects at lower elevations and on steep solar aspects higher up. Old wind slabs were on a variety of aspects behind exposed terrain features. The surface hoar (5-10mm) was most prominent at and above the recent cloud associated with inversion conditions. Friday's moist snowfall may have destroyed this surface hoar in many places. Surface facets have grown particularly on northern aspects where colder temperatures have persisted. In general the snowpack is now well bonded in most locations. A mid-pack layer of concern is a rain crust (buried on Feb 1st) now down 10-40 cm, which exists up to about 2000 m. This may have potential to become reactive with additional snow load in areas where additional crusts do not lie above it, such as north aspects at treeline. Lower layers include a mid-January crust (down 50-100 cm), and a mid-December crust (down up to 200 cm); these now only present concerns in shallow snowpack areas. The average treeline snowpack depth at is around 240cm.

Problems

Wind Slabs

An icon showing Wind Slabs
Fresh snow and variable winds have formed isolated wind slabs in the immediate lee below ridgelines and behind terrain features.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Feb 14th, 2012 3:00AM

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