Avalanche Forecast

Issued: Nov 21st, 2015 7:58AM

The alpine rating is below threshold, the treeline rating is below threshold, and the below treeline rating is below threshold. Known problems include Wind Slabs and Persistent Slabs.

rbuhler, Avalanche Canada

Kootenay Boundary.

It's early in the season but there is more than enough snow for avalanches. If you are out in the mountains, please post your observations to the Mountain Information Network.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

High pressure will remain the dominant feature on Sunday. Sunny and dry conditions are expected in the morning with increasing cloudiness in the afternoon. A temperature inversion is expected with warm air sitting around 2500m and alpine winds should be light to moderate from the NW. On Monday, a weak storm system reaches the region. 4-8mm of precipitation are forecast for parts of the region on Monday. Freezing levels are forecast to reach 1200-1500m on Monday afternoon and moderate SW winds are expected in the alpine. A lull in the storm is forecast for Monday evening or overnight before a second pulse arrives. Another 8-12mm are forecast for the wet parts of the region. Dry arctic air is expected to arrive late Tuesday and push out any remnants of the storm.

Avalanche Summary

No recent avalanches have been reported. A natural avalanche cycle up to size 2.5 occurred during last weekend's storm.

Snowpack Summary

Check out the recent conditions video from Whitewater at: https://youtu.be/lmM4gDom1wM. There is certainly enough snow for avalanches, with anywhere from 60-150cm of snow sitting on the ground. A thick crust layer sits down as deep as 50cm but the stability and distribution of this layer throughout the region is not yet known. Dig down and test this layer before committing to avalanche terrain. Wind slabs in leeward features may be sensitive to human-triggering. If you're out in the mountains, please send us your reports.

Problems

Wind Slabs

Recent wind may have formed soft wind slabs in leeward features. Use extra caution in wind affected terrain.

Use caution in lee areas in the alpine. Recent wind loading may have created wind slabs. >Be cautious as you transition into wind affected terrain.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The reactivity of the crust layer down 20-50cm is unknown and should be treated with extra caution until there is more information.

Choose well supported terrain without convexities. >If you plan on increasing your exposure to avalanche terrain, do it gradually as you gather information.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 4

Valid until: Nov 22nd, 2015 2:00PM