Avalanche Forecast

Issued: Mar 10th, 2016 7:39AM

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

pmarshall, Avalanche Canada

Sea To Sky.

Extreme winds on Thursday and ongoing wind-loading on Friday will keep danger high in the alpine. Give all this new snow a couple days to settle before pushing out to bigger more committing terrain.

Summary

Confidence

Moderate

Weather Forecast

FRIDAY: Cloudy with a chance of sunny breaks followed by light snow 5-10 cm. The freezing level is around 1200-1400 m and winds are moderate from the south. SATURDAY: Periods of snow 20-30 cm. The freezing level is around 1200 m and winds are moderate gusting strong from the SE-SW. SUNDAY: Mainly cloudy with flurries. The freezing level hovers around 1200 m and winds ease to light.

Avalanche Summary

A widespread and large natural avalanche cycle probably occurred overnight Wednesday and on Thursday in response to rapid loading from snow and wind. All this new snow may take a couple days to settle and strengthen. Rider triggering remains likely on Friday, particularly in steep wind-loaded terrain.

Snowpack Summary

By Friday morning many areas could see as much as 100 cm of new snow on the ground. Weaknesses within or at the base of the new storm snow may need a couple days to settle and strengthen. Extreme southerly winds have created very deep and dense slabs in lee terrain, probably well below ridge crests, while scouring windward slopes. Ongoing stormy weather has also encouraged extensive cornice growth. The mid and lower snowpack are strong and well-settled.

Problems

Storm Slabs

Triggering deep fresh storm slabs remains a concern on Friday. Winds are also forecast to remain fairly strong resulting in further wind loading on northerly aspects, and the potential for natural releases.

Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.>Be cautious as you transition into wind affected terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

2 - 5

Cornices

Cornices are reported to be massive and weak. These could pop off at any time, but are more likely to fail with continued growth or during brief sunny breaks.

Avoid steep slopes below cornices.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Mar 11th, 2016 2:00PM