Avalanche Forecast

Issued: Mar 9th, 2013 9:10AM

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

Avalanche Canada jlammers, Avalanche Canada

Summary

Confidence

Fair - Track of incoming weather is uncertain on Monday

Weather Forecast

Overnight and Sunday: Increased cloud with trace amounts of new snow / Light southwest winds / Freezing level at 1200mMonday: Moderate to locally heavy snowfall in the south of the region / Moderate to strong west winds / Freezing level at 1600mTuesday: Continued snowfall / Moderate southwest winds / Freezing level at 1100m Note: The track of Monday's system is uncertain with some weather models showing the main pulse having the greatest impact south of the border. We should have a better handle on forecast snowfall amounts on Sunday.

Avalanche Summary

Although reports were limited at the time of publishing, warming most likely triggered a round of loose wet avalanche activity on sun-exposed slopes on Saturday.

Snowpack Summary

Dribs and drabs of recent snowfall overlie old wind slabs in exposed areas, and mingle with spotty surface hoar or facets in sheltered locations. A sun crust exists on south facing terrain. Below 1400m in the north and 1700m in the south the light amounts of recent snow overlie a thick rain crust.Between 60-100cm below the surface is a layer of surface hoar which was buried on February 20th. This layer was the culprit in most of the large avalanches that occurred last weekend. Triggering this layer is becoming more difficult, but I would recommend using increased caution on large, unsupported slopes that did not release during the avalanche cycle last weekend. Below this the snowpack is generally well settled and strong.

Problems

Persistent Slabs

An icon showing Persistent Slabs
60-120 cm of snow sits on a persistent layer of surface hoar that was highly reactive last week. Extra caution should be given on unsupported slopes over 30 degrees that did not previously slide.
Conditions have improved, but be mindful that deep instabilities are still present.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Mar 10th, 2013 3:00PM

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