Avalanche Forecast

Issued: Mar 15th, 2013 3:00PM

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

Alberta Parks mike.koppang, Alberta Parks

Warm temps persist!  Lower elevations are isothermal in many places.  Watch for large cornices looming overhead.

Summary

Confidence

Good

Weather Forecast

Freezing levels are forecast to begin to drop on Saturday but not until later in the day.  Cloudy conditions will persist overnight so we expect there to only be a minimal "re-freeze" of the snowpack over the next 24hrs.  Light snow will begin to fall when the cooler air arrives but snowfall amounts are not expected to be that significant.

Avalanche Summary

Numerous loose wet slides were observed below treeline up to sz 1.  Also one sz 3 avalanche was observed on the Nestor slide paths that had a fracture depth of over 1m and was close to 300m wide.  This slide ran from "dry" alpine terrain into the below treeline moist isothermal snowpack.  A few other isolated avalanches up to sz two caused by cornice collapses were also observed.

Snowpack Summary

Moist isothermal snowpack below 1900m throughout the region.  Top 40cm of snowpack moist up to 2200m.  Above 2200m snowpack is still wintery in most places.  The 0303 temperature crust is present on all solar aspects up to 3000m and now has about 40cm of snow overlying it that seems well bonded.  Skiing is rugged.

Problems

Storm Slabs

An icon showing Storm Slabs
Widespread storm slabs have developed over the past few days in Alpine terrain. These slabs are 40-60cm thick and are fairly stiff due to warm temps and recent strong winds.  Be aware for potential for remote propagations. 
Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Avoid freshly wind loaded features.>Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 6

Loose Wet

An icon showing Loose Wet
Loose wet slides are being observed below treeline (below 1900m) in many areas.  These slides are failing at ground in the weak isothermal snowpack.
Watch for wet loose or slab activity with forecast rain and/or warm temperatures.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 3

Valid until: Mar 16th, 2013 2:00PM