Avalanche Forecast

Issued: Apr 8th, 2012 10:25AM

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

Avalanche Canada ghelgeson, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Monday is the tail end of the beautiful weather pattern we've been in for the past few days. The upper flow switches from northerly to a more mild southerly on Tuesday which will push freezing levels above 3000 m. Monday: Freezing level starts near the surface, topping out around 2500m. A few clouds build into the region in the afternoon. The current forecast shows that Monday night is the last good overnight refreeze until next weekend. Tuesday: Temperatures should already be near 2000 m at dawn and are forecasted to continue to climb to 3000 m by lunch time. Cloud cover increases to 50% as winds Light southeast winds are forecast for at all elevations Tuesday. Temps remain high through the night. Wednesday: Freezing level stays around 3000 all day. Ridge top winds strong SE diminishing in speed at lower elevations.

Avalanche Summary

No avalanche activity reported Saturday or Sunday. On Friday in the Fernie area a skier triggered a size 1.5 avalanche with a 20 cm crown on an E facing slope at 2000 m Friday. Some loose snow activity on a SE facing slope was also reported, but, there is surprisingly little avalanche activity in the region currently.

Snowpack Summary

Mild temperatures in combination with the strong spring sun have helped to settle out the 20 cm from Wednesday's storm which came to rest on the April 4th melt/freeze crust. At this point last weeks storm snow has seen a lot of the sun & it has behaved quite well, producing very little in the way of avalanches. Recent storm snow has added up to 60-120 cm depending on the drainage. Our field team was out in the region Saturday; they were able to find the March 27th interface down around 90cm below the snow surface but test profiles did not produce any results on this layer. Large cornices loom over many lee slopes. Glide cracks are a concern, be sure to give them a wide berth as they are very sensitive and could fail at any moment.

Problems

Loose Wet

An icon showing Loose Wet
Intermittent strong sun is forecast for Monday as convective clouds and the sun dance through the sky. Watch for loose snow avalanches, with the potential for deeper slab avalanches on slopes that bake all day under the strong spring sun.

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

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Cornices

An icon showing Cornices
Cornices have grown large & unruly. Cornices receiving direct sun will eventually grow weak & there is potential for cornice fall to initiate deep persistent slab avalanches on underlying slopes. Pay attention to what's happening above you.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

3 - 7

Persistent Slabs

An icon showing Persistent Slabs
The odd deep slab could still be out there, I'm still suspect of steeper unsupported slopes & places where the snowpack goes from thick to thin, especially near ridge crest and around rock outcroppings.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Apr 9th, 2012 9:00AM

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