Avalanche Forecast

Issued: Nov 23rd, 2017 3:00PM

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

Alberta Parks KESAdmin, Alberta Parks

Cooler temps will move back into the forecast area overnight.  Watch for new thin wind slabs in alpine areas.  Rugged travel anywhere below 2500m.

Summary

Confidence

Moderate -

Weather Forecast

Snowfalls will begin to taper overnight and freezing levels will drop to the valley bottom.  We should see some recovery in the snowpack overnight but it will take a few days for the cool temps to fully penetrate the snowpack.  Winds will be SW on Friday with Alpine temps of -10C.

Avalanche Summary

Evidence of a few paths going sz 2 - 2.5 over the past 24hrs.  Most of the debris was stopping at the middle or bottom of the tracks of the slide paths.

Snowpack Summary

Freezing levels were around 2600m on Wednesday evening and finally began dropping late thursday afternoon.  So far lower elevations have seen a large decrease in snowpack depths due to warm temps and rainfall while treeline depth are still around 1m.  The recent rapid loading caused a natural avalanche cycle with many paths going sz 2-2.5 failing on either the Halloween crust or the Oct 17th melt freeze crust.  As this layer freezes overnight we will now start to have a new layer in the snowpack.  The November rain crust.  Conditions will tighten up with teh cooling overnight but it will take  afew days for teh cooler temps to penetrate the snowpack.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Wind slabs are now beginning to fail down 30-50cm on the Halloween crust. in some areas they are stepping down to the october 17th crust.  Gullies and pockets along ridgelines are best avoided.
Be aware of the potential for wide propagations due to the presence of hard windslabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Thin new wind slabs will build in Alpine terrain overnight and throughout Friday.
Avoid freshly wind loaded features.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Nov 24th, 2017 2:00PM