Avalanche Forecast

Issued: Dec 3rd, 2016 3:36PM

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

Alberta Parks mike.koppang, Alberta Parks

Avalanche danger will be slowly increasing over the next 24hrs with 20cm of forecast snow and moderate winds.  If forecasted snowfall amounts do not arrive, we will likely see the danger remain at Moderate in Alpine. 

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Sunday

Weather Forecast

10cm of snow is forecast to fall overnight and an additional 5-10cm throughout the day on Sunday.  This new snow is forecast to fall under a moderate westerly wind and cooler temperatures so we are going to see avalanche danger begin to increase in Alpine areas.  We are expecting new slabs to build throughout the day. 

Avalanche Summary

No new natural avalanche activity was observed.

Snowpack Summary

30-50cm of snow is overlying the November 12th Melt freeze crust which is being found up to 2500m on all aspects.  So far, field tests are showing that overlying snow is bonding to this crust fairly well.  This may change as more load is applied to the crust.  In alpine area in immediate lees, pockets of pencil hard windslab are being encountered up to 20cm thick.  These slabs do not extend far downslope, but they are certainly in the realm of being triggerred by a skier. 

Problems

Storm Slabs

An icon showing Storm Slabs
New storm slabs will be building throughout the day on Sunday with the new snow and forecasted westerly winds.
Avoid freshly wind loaded features.The recent snow may now be hiding windslabs that were easily visible before the snow fell.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs
Isolated pockets of windslabs in alpine areas on northern aspects. These slabs are up to 20cm thick, pencil hard but do not extend far downslope.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.The recent snow may now be hiding windslabs that were easily visible before the snow fell.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Dec 4th, 2016 2:00PM

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