Avalanche Forecast

Issued: Feb 22nd, 2013 3:00PM

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 burke.duncan, Alberta Parks

New snow and strong winds forecast to arrive overnight on Friday evening.  Watch for decreasing stability. 

Summary

Confidence

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

Weather Forecast

The storm that was forecast to arrive on Friday afternoon has now been pushed back to Friday night.  We expect snow to begin falling around 19:00 and continue into the morning with total accumulations of 15-20cm.  Winds will be STRONG out of the SW so new slabs will be quick to develop.

Avalanche Summary

No new avalanches were observed but conditions were obscured throughout the day.  Likely there was loose dry sluffs up to sz 1 from steep unskiable terrain throughout the day.

Snowpack Summary

5cm new snow overnight in the core areas of the forecast area with strong westerly winds.  Touchy slabs building in Alpine terrain and in steep unsupported area at treeline.  Watch for pockets of unstable snow along ridge crests, along moraines, and in gullied terrain features, especially along lee aspects.

Problems

Storm Slabs

An icon showing Storm Slabs
Fresh storm slabs are building in open wind affected terrain.  Be aware of these new slabs as you transition into open wind affected terrain. 
Avoid freshly wind loaded features.>Avoid lee and cross-loaded terrain near ridge crests.>

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 4

Loose Dry

An icon showing Loose Dry
Numerous loose dry sluffs up to size 1 were observed on lee aspects throughout the day again on Friday due to wind action.
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 - this was the failure plane for an avalanche involvement on Thursday in the Hero's Knob area.
Whumpfing is direct evidence of a buried instability.>Be aware of the potential for wide propagations due to the presence of hard windslabs.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 4

Valid until: Feb 23rd, 2013 2:00PM