Avalanche Forecast

Issued: Apr 10th, 2013 6:25PM

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

chris gooliaff, Parks Canada

Banff Yoho Kootenay.

A brief storm this evening and overnight will create touchy storm slabs in the alpine.

Summary

Weather Forecast

Temperatures will drop with the passing of this storm front, bringing moderate to strong NW winds on Thursday. Unsettled conditions will result in squalls, delivering light amounts of snow.

Snowpack Summary

In the ALP and TL, recent storms have previously deposited 10-30 cm of snow which sits on top of suncrusts on solar aspects and facetted snow on polar aspects. Windslabs exist in immediate lee features in the alpine, and are developing with the current strong SW winds. The addition of up to 10-20cm of snow tonight will create touchy storm slabs.

Avalanche Summary

Yesterday, a field team in the White Pyramid area on the 93N remote triggered a small, thin windslab of little consequence in the alpine today. Reports indicate increased winds were causing numerous loose dry avalanches out of steep alpine terrain. We expect a natural avalanche cycle to occur during the peak of the storm tonight.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Storm Slabs

The forecasted precipitation, winds, and increased temps will create new storm and windslabs that will be most reactive during the storm. Natural activity will decrease once the system passes, but the newly formed slabs will take a few days to settle

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Dry

Increased winds today caused numerous loose dry avalanches in steep alpine terrain. Forecasted new snow, winds and warming temps will increase activity in this terrain. This is of particular concern for climbers or skiers entering steep couloirs.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 11th, 2013 4:00PM