Avalanche Forecast

Issued: Mar 8th, 2014 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Freezing levels are very important over the next 24hrs.  We are forecasting HIGH below treeline because we anticipate some of the new snow to fall as rain.  Lots of recent skier triggerred avalanches at treeline on the 0211 interface at treeline.

Summary

Confidence

Fair - Freezing levels are uncertain on Sunday

Weather Forecast

A fairly significant pulse of snow is expected to cross over the region tonight. Some of this snow may fall as rain at lower elevations so we may see a rapid rise in avalanche danger in these areas.  Snowfall amounts for the spray are 20-25cm while the Aster lake region may see up to 30cm of snow.  Freezing levels are expected to drop following the passage of this system but at the time freezing levels are still around 1900m.  Winds are forecast to be moderate to strong out of the SW.

Avalanche Summary

Two skier accidental avalanches were reported into the office on Friday and forecasters were able to remotely trigger two sz 2 avalanches from open treed terrain on friday. All avalanches were failing at the 0211 interface which consists mainly of facets up to sz 3.  A few loose wet avalanches were also observed below treeline.

Snowpack Summary

Warm temps prevailed again today.  Freezing levels climbed to 2000m today and moist snow was being observed on solar aspects up to 2500m when the sun came out.  The upper snowpack is rapidly settling.  The 0303 interface is gaining strength but the 0211 interface is becomming more reactive to skiers. 

Problems

Persistent Slabs

An icon showing Persistent Slabs
Numerous skier triggered avalanche have recently occurred on this layer indicating how sensitive it is to skier triggering.
Use careful route-finding and stick to moderate slope angles with low consequences>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>Choose well supported terrain without convexities.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 5

Storm Slabs

An icon showing Storm Slabs
New storm slabs will develop overnight if the forecasted 25cm of snow arrives with the moderate SW winds. This additional load will make the 0211 interface even more reactive to light loads.
Avoid freshly wind loaded features.>Avoid lee and cross-loaded terrain near ridge crests.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Wet

An icon showing Loose Wet
Some precipitation may fall as rain at lower elevations throughout the evening. As a result, we may see loose wet slides or wet slabs failling full depth during the frontal passage.
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 9th, 2014 3:00PM