Avalanche Forecast

Issued: Mar 7th, 2013 3:00PM

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

Alberta Parks burke.duncan, Alberta Parks

Snowfall totals by Thursday midday were less than forecast and with calm wind conditions little redistribution of snow was occurring.  Watch for rising temps and the influences of daytime heating over the next few days as warmer weather moves in.

Summary

Confidence

Good

Weather Forecast

Barometric pressure will rise steadily on Friday as a ridge of HIGH pressure moves into the area. Light flurries over Thursday night tapering off Friday AM with skies expected to clear as the day progresses.  Light to moderate NW winds and alpine temps ranging from -8 to -12.  Valley bottom temps a  few degrees warmer and winds generally light from the West.

Avalanche Summary

Widespread sluffing of loose dry storm snow on steep lee aspects in the alpine elevation zone through the day on Thursday.  No other avalanche activity observed or reported.

Snowpack Summary

8cm of new snow by Thursday morning at treeline with an additional 3-5cm through the day.  Winds generally calm all day with brief sunny periods depending upon location.  The storm slabs are slowly settling and bonding to previous surfaces and the lack of wind is slowing the pace of softslab formation and cornice growth. 

Problems

Storm Slabs

An icon showing Storm Slabs
Snow from the most recent storms which totalled as much as 50-70cm is settling out. Slab development is present in lee and cross-loaded terrain. The natural avalanche cycle has tapered off, but prime conditions exist for human triggering.
Assess start zones carefully and use safe travel techniques.>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 - Very Likely

Expected Size

2 - 5

Cornices

An icon showing Cornices
Cornices growth has slowed during the recent period of relatively calm wind conditions. Cornice failures earlier in the week triggered slab avalanches up to Size 3 on the slopes below.
Avoid areas with overhead hazard.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Loose Dry

An icon showing Loose Dry
Recent snowfall and light/moderate winds has led to sluffing from steep terrain on all aspects at all elevations.  This pattern is continuing with steady light snowfalls expected to continue until Friday AM.
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Avoid lingering in runout zones.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Valid until: Mar 8th, 2013 2:00PM