Avalanche Forecast

Issued: Dec 4th, 2015 7:42AM

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

triley, Avalanche Canada

Sea To Sky.

High avalanche danger this weekend. Very conservative travel will be required during this stormy period.

Summary

Confidence

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

Weather Forecast

Light snow should continue this evening bringing 5-8 cm above 1000 metres and moderate southwest winds in the alpine. Heavy precipitation driven by strong southerly winds should arrive during the night and result in 15-25 cm of new snow above 1200 metres. The storm should continue during the day Saturday and result in another 20-30 cm by Sunday morning. Freezing levels are forecast to rise sharply Sunday night to 2000 metres as the wet storm continues. Repeat for Monday!

Avalanche Summary

Widespread natural avalanche activity occurred during the Thursday storm. Areas that did not slide continue to be suspect. New storm slabs are expected to develop on Saturday.

Snowpack Summary

Deep storm slabs have developed in the alpine and at treeline above old wind crusts, melt-freeze crusts, and weak facetted crystals in some areas. Shallow facetted areas at treeline may now be buried by 70-100 cm of wind transported new snow. Cooler temperatures have re-frozen the moist or wet snow at lower elevations into a solid base layer.

Problems

Storm Slabs

Storm slabs will continue to develop with each wave of Pacific moisture. Avalanche size and frequency are expected to increase throughout the weekend.

Be alert to conditions that change with elevation.>Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Valid until: Dec 5th, 2015 2:00PM