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Avalanche Forecast

Apr 8th, 2012–Apr 9th, 2012
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: South Rockies.

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.

Avalanche Problems

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

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

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