Avalanche Forecast

Issued: Feb 21st, 2013 8:14AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs, Loose Dry and Wind Slabs.

Alberta Parks mike.koppang, Alberta Parks

Skier accidental avalanche on Heros knob today (see forecast details tab for details).  Up to 20cm of new snow forecast to fall in the region starting late in the day on Friday. Avalanceh danger is increasing at this time.

Summary

Confidence

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

Weather Forecast

A fast moving low pressure system is forecast to track across the forecast region bringing with in new snow (up to 20cm) and strong SW winds at higher elevations.  Temperatures will remain cool with only -10C as a high at 3000m.  The bulk of the new precipitation is forecast to hit the region later in the day on Friday.

Avalanche Summary

A report into the office of a skier accidental sz 2 avalanche on an East aspect at 2600m in the Heros knob area.  Skier started down slope, fell due to a shallow rock and lost both skis.  While walking up to grab his skis the slope released and the skier went for a 500m ride.  The skier came to rest buried up to his waist with only minimal injuries and 1 lost ski pole.

Snowpack Summary

Field teams in the Aster lake area report light snowfalls throughout the day with moderate SW winds.  Storm slabs up to 30cm thick are beginning to build in open alpine terrain with the recent winds.  No reports of cracking or whumnpfing but forecasters were reporting the snowpack starting to feel "Cakey".  These new slabs are overlying a variety of previous snow surfaces from hard slabs, sastrugi and or gravel. 

Problems

Storm Slabs

An icon showing Storm Slabs
New storm slabs are forecast to develop in Alpine terrain with the arrival of the low pressure system on Friday afternoon.  These slabs will develop quickly with the associated strong SW winds.
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 Dry

An icon showing Loose Dry
Numerous loose dry sluffs up to size 1 were observed on lee aspects throughout the day on Thursday.
Be cautious of sluffing in steep terrain.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs
Pockets of soft slab are present in lee and cross-loaded features in the alpine. These recent slabs sit on an old smooth layer of hard slab.  One skier was involved in an avalanche on this layer see Forecast details tab for more information
Avoid convexities or areas with a thin or variable snowpack.>Avoid cross loaded slopes at or above treeline.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 22nd, 2013 2:00PM