Avalanche Forecast

Issued: Apr 2nd, 2012 10:34AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include Loose Wet, Storm Slabs and Cornices.

Avalanche Canada mbender, Avalanche Canada

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather is uncertain on Tuesday

Weather Forecast

TUESDAY: Light to moderate precipitation with strong winds from the southwest. Freezing level at 1500m. WEDNESDAY: Light to locally moderate precipitation winds light from the west and freezing levels remain at 1500m. THURSDAY: Light precipitation with a freezing level of 1300m.

Avalanche Summary

The region has been very active with avalanches the past several days. Natural, explosive and human triggered avalanches have been reported up to size 2.5. Reports come from all aspects, with a bias to north facing slopes. At lower elevations (where the surface is moist) these are running as loose events and at higher elevations the new snow is propagating as a slab. Remote triggering has also been observed.

Snowpack Summary

Up to 100cm of new snow has fallen since March 26. Shears within the upper storm snow are tightening with the persistent warm temperatures, although a reactive layer down 40-50cm remains. The March 26 interface is a melt freeze a crust on all aspects except true north treeline and alpine, where small surface hoar (5mm) is present in sheltered places. The bond at this interface is gaining strength, with lingering concerns on true south aspects where the crust is thickest and where the surface hoar lurks. At lower elevations, the consistent high freezing levels have kept the new snow heavy and moist. The deep, persistent early February surface hoar lingers in the snowpack giving sudden results in testing. Concern remains with heavy triggers (cornice), step down avalanches and rapid loading from intense precipitation, strong winds or sun.

Problems

Loose Wet

An icon showing Loose Wet
High freezing levels will promote rain at lower elevations.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Storm Slabs

An icon showing Storm Slabs
Up to 100cm of new snow has fallen recently and has incrementally overloaded buried weak layers. Moderate to strong winds have created windslabs in the lee of terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Cornices

An icon showing Cornices
Cornices continue to grow. There is potential for triggering deep persistent slabs on underlying slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 7

Valid until: Apr 3rd, 2012 9:00AM

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