Avalanche Forecast

Issued: Feb 26th, 2016 8:00AM

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

chris gooliaff, Parks Canada

Glacier.

Extra caution is still needed if traveling on or below sunny slopes. The sun's heat beating down on these slopes will elevate danger levels.

Summary

Weather Forecast

One more day of sun and the region moves back into a stormy trend. Today brings sun with increasing cloud late in the day. Freezing levels rise to 1800m and winds remain light SW. Tonight and tomorrow bring flurries, amounting to 5cm, freezing levels dropping to 1100m, and winds increasing to moderate SW. Sunday shows continued flurries.

Snowpack Summary

The sun has formed a breakable crust on SE through W aspects to near ridge-top elevations. Soft, faceted powder still prevails on polar aspects. Soft slabs in the upper 50cm can be found near ridge crests, but are more stubborn to move now. The Feb 10th surface hoar/suncrust is down 50-90cm and is much less reactive than a few days ago.

Avalanche Summary

Several loose, moist avalanches to size 3 were observed yesterday in the highway corridor, mainly off the steep south face of Tupper. These occurred during the heat of the late morning sun, which should provide incentive to get going early and use the solid overnight freeze as a safety buffer.

Confidence

Problems

Persistent Slabs

Feb 10 interface lingers and is becoming difficult to forecast. In some areas there is surface hoar on a crust which is a good recipe for bad avalanches. It may become reactive given prolonged sun or added load such as cornice fall or slab avalanche

Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Cornices

Cornices are being stressed by the warm temp's and grew quite large during the last storm. If they drop, they could trigger deeper weak layers and cause large avalanches.

Cornices become weak with daytime heating, so travel early on exposed slopes.Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Wind Slabs

Soft windslab can be found in immediate lee features in the alpine and at tree-line. These slabs are also present on exposed alpine features, like large convex rolls. They are becoming more stubborn to trigger.

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Feb 27th, 2016 8:00AM