Avalanche Forecast

Issued: Mar 25th, 2013 3:00PM

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

Alberta Parks jeremy.mackenzie, Alberta Parks

Cool temperatures are preventing Spring from settling in completely. Winter-like avalanche concerns still exist at higher elevations, especially on N aspects. Keep a close eye on solar radiation on S, SW and W aspects.

Summary

Confidence

Good

Weather Forecast

Alpine temperatures will still be cool on Tuesday, but solar radiation is intense. The freezing level will rise to 1900m. Winds should remain light from the North and no precipitation is in the forecast.

Avalanche Summary

Nothing new observed today.

Snowpack Summary

Daily melt-freeze cycles continue, but only on steep S, SW and W aspects. Otherwise little change in the snowpack. Buried wind slabs still exist in Alpine and Treeline terrain. These slabs are a concern in unsupported convex features. A variety of crusts are found depending on aspects and elevation, which should be monitored carefully. Cornices are quite large and are becoming sensitive to triggering in the afternoon due to intense solar radiation.

Problems

Wind Slabs

An icon showing Wind Slabs
Buried wind slabs are still a concern in steep, convex and unsupported features. These slabs are hidden under last week's snowfalls so take the time to dig down and evaluate their presence and sensitivity.
Choose well supported terrain without convexities.>Avoid lee and cross-loaded terrain near ridge crests.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Cornices

An icon showing Cornices
Cornice failures continue to be a theme, with several failures triggering slab avalanches in recent days. Be aware of overhead exposure especially during times of intense solar radiation.
Cornices become weak with daytime heating, so travel early on exposed slopes.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 5

Persistent Slabs

An icon showing Persistent Slabs
A few crust layers are found in the upper snowpack. These crusts reach as high as 3000m on S aspects and 2200m on other aspects. Monitor the location of these layers within the snowpack and assess the bond with layers above.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 5

Valid until: Mar 26th, 2013 2:00PM