Avalanche Forecast

Issued: Mar 11th, 2014 8:08AM

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

ali haeri, Parks Canada

Glacier.

Clear skies with strong solar inputs today will mean deteriorating conditions on solar aspects. Moist snow and loose avalanches from rocky features are good indicators of this. Manage your exposure to overhead cornice hazard as a result.

Summary

Weather Forecast

Ridge of high pressure over the interior will maintain clear and cooler temperatures for today. Freezing levels are expected to rise tomorrow with temperatures reaching into the positives values in the alpine. Light disturbance on Thursday will bring cloud and light snow.

Snowpack Summary

Rain crust below 1700m on the surface. Above tree line the snow is wind affected. Generally heavy over light conditions until the snow settles. March 2nd crust is down around 1m. The Feb. 10 surface hoar/crust interface is down around 1.5 to 2m. The mid and lower snowpack is well settled.

Avalanche Summary

From yesterday there was one size 3.0 natural slab avalanche in the highway corridor and some smaller avalanches closer to highway level on steep rock cuts. Operations in the area are reporting many skier accidental and remote avalanches failing in the storm snow or deeper on the buried weak layers.

Confidence

Problems

Storm Slabs

Storm snow instabilities are present from snowpack tests yesterday. There is wind affect above treeline and lingering windslabs may exist in exposed areas.

Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Cornices

Cornices have grown from the last storm. Strong solar radiation with warming temperatures will mean an increased hazard of cornice fall for today and tomorrow.

Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

2 buried weak layers have been reactive this week. Down ~1m, is a sun crust on south and west aspects. The other is the other is Feb. surface hoar/crust layer down ~1.5m-2m which still shows wide propagation potential in snowpack tests.

Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

3 - 4

Valid until: Mar 12th, 2014 8:00AM