Avalanche Forecast

Issued: Mar 22nd, 2016 9:01AM

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

jlammers, Avalanche Canada

Sea To Sky.

The Avalanche Danger is expected to rise throughout the day on Wednesday, and heavy accumulations are possible in the far south of the region. Pay close attention to how much snow falls in your area, and be prepared to back off to simple terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

On Wednesday expect 10-25cm of new snow to fall throughout the day with strong southwest ridgetop winds. The highest accumulations are expected in the south of the region. Continued light flurries and decreased winds are forecast for Thursday, while clearing skies are forecast for Friday. Freezing levels should sit at 1400m on Wednesday, 1200m on Thursday, and 1600m on Friday.

Avalanche Summary

In recent days a few soft slabs to size 2 were observed failing within the new storm snow at treeline and in the alpine. Daytime warming and solar radiation also triggered loose wet avalanches to size 2.5 in steep sun-exposed terrain. Forecast cooling should limit ongoing loose wet avalanche activity; however, a round of natural wind slab activity is expected on Wednesday in response to new snow and strong southwest winds.

Snowpack Summary

On Sunday night the region received between 12 and 30cm of new snow with highest amounts falling in the Southern Garibaldi/ Brandywine parts of the region. Moderate southerly winds formed soft slabs which seemed most reactive in lee alpine terrain. Warm temperatures and the "greenhouse effect" from cloudy skies on Tuesday have surely promoted significant settlement within the recent snow The new accumulations overlie a sun crust on sun-exposed slopes, dry settled powder on shady slopes and moist snow below 1800m. Below the new snow the snowpack is strong and well-settled throughout with no notable persistent weaknesses. Cornices are huge and fragile.

Problems

Wind Slabs

New snow and strong winds forecast for Wednesday will promote new wind slab formation at treeline and in the alpine. New wind slabs are expected to increase in size and reactivity throughout the day.

Stay off recent wind loaded areas until the slope has had a chance to stabilize.>Be cautious as you transition into wind affected terrain.>Be alert to conditions that change throughout the day.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 3

Cornices

Some cornices are the size of a bus, and will continue to grow with forecast snow and wind. Give these monsters a wide berth when traveling on or below ridge crests.

Give cornices a wide berth when travelling on or below ridges.>Extra caution needed around cornices with current conditions.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 5

Valid until: Mar 23rd, 2016 2:00PM