Avalanche Forecast

Issued: Dec 10th, 2014 8:17AM

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

ccampbell, Avalanche Canada

Sea To Sky.

Fresh storm and wind slabs will likely take a few days to strengthen.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

Expect another 10-20 cm of snow on Thursday falling mainly in the morning and afternoon with freezing levels around 1400 m and moderate to strong southerly ridge top winds associated with the precipitation. After another 15-25 cm overnight, a drying, clearing, and cooling trend is expected to start on Friday with isolated flurries, freezing levels dropping as low as 1000 m and winds easing to light westerlies by the evening. At this point Saturday is looking mostly dry with a mix of sun and cloud, freezing levels below 1000 m and light ride top wind.

Avalanche Summary

Reports from Tuesday include numerous natural wet storm slab avalanches up to Size 2 at treeline and alpine elevations. Several were triggered by cornice collapses.

Snowpack Summary

Fluctuating freezing levels and heavy precipitation has generally resulted in rain-soaked snow that should soon be frozen into a solid crust that extends as high as alpine elevations with 15-20 cm of fresh wet snow stuck on top, depending on elevation. Meanwhile in the high alpine, deep fresh storm and wind slabs have likely developed, and weakness deeper in the snowpack, such as crusts with associated facets, likely remain under critical loads. The snow pack depth drops significantly below treeline with essentially no snow below 1600 m.

Problems

Storm Slabs

resh new storm and wind slabs are likely susceptible to human triggering especially on the northwest through northeast side of terrain breaks. Facet/crust weaknesses deeper in the snowpack are likely under critical loads at treeline and above.

Expect conditions to deteriorate. Assess conditions continually as you travel and be prepared to change plans.>Be alert to conditions that change with elevation and avoid wind loaded slopes near ridge crests.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 5

Loose Wet

Loose wet sluffs remain a concern in steep rocky terrain and gullies.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Be aware of party members below you that may be exposed to your sluffs.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Dec 11th, 2014 2:00PM