Avalanche Forecast

Issued: Mar 16th, 2015 9:16AM

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

pgoddard, Avalanche Canada

Sea To Sky.

Now that the storm is over, signs of avalanche danger may be less obvious. Touchy wind slabs are lingering. If its sunny, avoid large sun-baked slopes.

Summary

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain on Thursday

Weather Forecast

A brief clearing is expected to continue on Tuesday morning, before a Pacific frontal system pushes ashore late that day. Generally light precipitation is expected on Wednesday and Thursday, with the freezing level around 1500 m and winds light to moderate from the S to SW. A more intense pulse of precipitation is expected mid to late Thursday.

Avalanche Summary

A cycle of wind slabs (most size 1, up to size 2) was reported on Sunday. These failed naturally and were triggered remotely by skiers as well. Many were on north aspects.

Snowpack Summary

Wind slabs (most recently formed with northerly winds, but previously lee to the S-SW) and wind-affected surfaces are the main theme at the snow surface. Wind slabs can be triggered with the weight of a person. Cornices may also be fragile. Older, buried wind slabs may be hard to spot. A crust/facet combo produces moderate, sudden results in snowpack tests. This layer is buried anywhere from 10 to 60 cm down. Below this crust, the snowpack is reported to be generally well-settled and strong. Below treeline, the diminishing snowpack is trending isothermal (same temperature throughout).

Problems

Wind Slabs

Touchy wind slabs have formed on many slopes due to switching wind directions. These can be triggered by the weight of a person or sled.

Avoid cross loaded slopes at or above treeline.>Travel on ridgetops to avoid wind slabs on slopes below.>Give cornices a wide berth when travelling on or below ridges.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 17th, 2015 2:00PM