Avalanche Forecast

Issued: Feb 4th, 2012 8:13AM

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

Alberta Parks mike.koppang, Alberta Parks

Watch for deteriorating stability throughout the day as temperatures warm up. These decreases in stability will be most apparent on thin rocky solar aspects so keep an eye on overhead terrain that may already be in the sun.

Summary

Confidence

Fair - Freezing levels are uncertain

Weather Forecast

High pressure ridge still dominating forecast region. Warm temps will continue, light winds are forecast with no new snow for the next few days.

Avalanche Summary

Numerous loose wet avalanches up to size 1.5 from steep solar aspects. Extensive snowballing in steeper terrain. Also, a few older slabs on E aspects at 3000m up to size 2 on Whistling Rock Ridge in steep (45deg) unsupported terrain. Likely caused by cornice collapses in the past 72hrs.

Snowpack Summary

Snowpack continues to settle with warm temps. Melt freeze crust on solar aspects up to 2900m that was breaking down and becoming moist by 11am. Widespreasd surface hoar growth up to 6mm on all aspects except steep solar. Suspect this will become a concern once snow arrives. HS on the French Glacier and on the Robertson Glacier was highly variable from 200cm to 40cm to bare ice in some places.

Problems

Loose Wet

An icon showing Loose Wet
Loose wet slides on steeper solar aspects related to daytime warming. Wet slides were observed up to 3000m in elevation.

Aspects: North, North East, East.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 3

Wind Slabs

An icon showing Wind Slabs
Wind slabs from the various wind events earlier this season are easily found on N and E aspects. Steeper unsupported terrain features are still good places to use caution.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Weak layers persist close to ground that if triggered from a weak area could cause a large destructive avalanche involving the entire winters snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Feb 5th, 2012 3:00AM