Avalanche Forecast

Issued: Dec 8th, 2014 8:03AM

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

ccampbell, Avalanche Canada

Northwest Coastal.

A warm, wet and windy storm is expect increase danger and result in natural avalanche activity.

Summary

Confidence

Fair - Due to the number of field observations

Weather Forecast

On Tuesday freezing levels are expected to rise as high as 1800 m while a Pacific frontal system brings another 20-40 mm of precipitation and strong southwesterly alpine winds. Wednesday is looking slightly drier and cooler with 5-10 mm of precipitation and freezing levels around 1500 m as the alpine winds shift to moderate southeasterlies. At this point, Thursday is looking totally dry as freezing levels drop down to 1300 m and winds ease off.

Avalanche Summary

No new avalanches were reported. A couple fresh natural wind slab avalanches were reported from an area northeast of Stewart on Friday. These slides were observed on west facing slopes near treeline, and were an average of 20 cm deep. Similar activity is possible throughout the region.

Snowpack Summary

Conditions vary significantly throughout the region. In general, the snowpack is shallow, facetted, and wind affected. Approximately 5-15 cm of recent warm storm snow sits on a mix of surface hoar or faceted snow in sheltered areas, and wind slab or ice crusts in exposed terrain. Strong NE-SE winds have created dense new wind slabs in alpine and exposed treeline areas on the leeward side of ridge crests and terrain features. The mid-November crust-facet layer is now 40-60 cm deep and recently gave easy to moderate shears in snowpack tests.

Problems

Storm Slabs

Heavy storm snow is expected to initially bond poorly and overload deeper weaknesses in the snowpack. Extreme southerly winds could also create dense wind slabs well below ridge tops.

Expect conditions to deteriorate. Assess conditions continually as you travel and be prepared to change plans.>Be cautious as you transition into wind affected terrain and avoid wind loaded slopes near ridge crests.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Loose Wet

Expect heavy loose wet sluffs in steep open terrain and in gullies.

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

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 9th, 2014 2:00PM