Avalanche Forecast

Issued: Mar 28th, 2014 9:33AM

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

mbender, Avalanche Canada

South Rockies.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain on Sunday

Weather Forecast

Saturday: Mainly cloudy with isolated flurries and some sunny breaks. Alpine temperatures 1 degrees. Freezing level 1500m. Winds moderate west.Sunday: Cloudy with light to moderate snowfall possible. Light southerly winds. Freezing level 1400m.Monday: Mix of sun and cloud with possible flurries. Light west winds. Freezing level 1700m.

Avalanche Summary

Recent observations are limited to loose snow avalanches running in steep terrain to size 1.5.

Snowpack Summary

See this great video from our South Rockies field team that does an awesome job of summarizing the current state of the snowpack.Winds have been out of the SW which has created fresh wind slabs in alpine and treeline lee terrain. Cornices have also become large and unstable. 60-90 cm of settling storm snow from the past week rests on a graupel layer that can be found in much of the region. This makes for around 90 cm on top of the mid march crust at this point. This crust exists on all aspects below 2000m and on solar aspects in the high alpine. North of Sparwood and in the Crowsnest Pass area, the buried crust seems more specific to previously sun-exposed slopes. The deep facet/crust persistent weakness buried at the beginning of February (now down up to 150cm) seems unlikely to trigger in areas where the hard, supportive exists. No matter where you are in the region, this weakness should stay on your radar as any activity at this interface would be large and destructive. Possible triggers include a large cornice fall, a large input in a thin snowpack area or solar warming.

Problems

Wind Slabs

Moderate southwest winds have created wind slabs in the lee of terrain features.

Be cautious as you transition into wind affected terrain.>Use ridges or ribs to avoid pockets of wind loaded snow.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Deep Persistent Slabs

The deep weak layers that formed in early February may be a bit touchier in the north of the region. Possible triggers at this point include a large cornice fall, surface avalanche in motion or solar warming.

Caution around convexities or areas with a thin or variable snowpack.>Consider the consequences of the terrain if an avalanche steps down to a persistent weakness.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

3 - 6

Valid until: Mar 29th, 2014 2:00PM