Summary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Monday: A cold front brings moderate snow overnight Sunday. This is forecast to continue on Monday until the front departs in the afternoon. Moderate to strong westerly winds, switching to north-westerly and decreasing. Freezing level falling to valley floor.Tuesday: A brief ridge of high pressure should bring a break in precipitation and possibly clear skies and sunshine, although northern areas will probably cloud over by afternoon. Light winds and cool temperatures.Wednesday: Light snow. Increasing westerly winds.
Avalanche Summary
A natural avalanche cycle is under way, however poor weather is limiting observations. Natural, skier-remote and accidental avalanches were observed on Sunday to size 2. Avalanches reported throughout the week illustrate the unpredictable nature of persistent weak layers in the upper snowpack. On Thursday, a skier triggered a size 2.5 slab very easily and very close to recent ski tracks, which failed on buried surface hoar. On Wednesday, a cornice fall triggered a size 2 slab on a north aspect, which failed on the Feb 16. weakness. On Tuesday, numerous size 2-3 avalanches ran naturally, or with a remote trigger, on a variety of slopes. Most failed on upper snowpack persistent weaknesses. These layers are touchy and are likely to fail under the new storm load, creating large or widely-propagating avalanches.
Snowpack Summary
40-80cm snow has fallen, with snowfall forecast to continue until Monday. Strong winds and fluctuating temperatures are creating storm slabs and wind slabs on a widespread basis. Persistent weak layers buried in February are a key concern at all elevations and could be easily triggered by storm slabs, wind slabs or sluffs, or with a light additional load (like a sled or skier). Avalanches may be unexpectedly large, given the amount of fresh snow. Large cornices also loom as potential triggers for deep avalanches.
pgoddard,
Avalanche Canada
