Avalanche Forecast

Issued: Jan 20th, 2015 7:42AM

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

Avalanche Canada Peter, Avalanche Canada

Dry and mild conditions should persist for at least one more day. Be alert to changing conditions from daytime warming and sunshine.

Summary

Confidence

Good

Weather Forecast

Synopsis: The ridge of high pressure will maintain dry and mild conditions on Wednesday. Freezing levels could climb to a little over 1500 m and ridge winds remain light. Expect more cloud with a chance of flurries on Thursday. The freezing level should drop back to 1000m but some areas could still see an above freezing layer in the alpine. We could see periods of moderate SW winds. The next system appears to arrive on Friday bringing moderate precipitation, rising freezing levels, and strong SW ridge winds.

Avalanche Summary

Several natural wind slab avalanches were reported during and at the end of the recent storm (ending early Monday). On Monday one natural size 3 avalanche and one size 1.5 accidentally triggered avalanche were reported from the South Chilcotin Mountains. These were both wind slabs on northerly aspects near ridge top. Info is limited from the Coquihalla and other southern areas but one observer noticed the deposits of several natural size 2-2.5 slides from the road.

Snowpack Summary

Recent snowfall amounts vary from north to south with an average of 25-35 cm of new snow near the Duffey Lake Road and 40-60 cm in the Cascades (Coquihalla and Allison Pass). Strong W-SW winds created deep and dense wind slabs in wind-affected terrain. The fresh storm and wind slabs overlie a hard crust and/or surface hoar layer. The bond to the crust could be somewhat variable but many observers report a good bond. Where surface hoar is present (possibly above the crust) the storm slab has been more reactive to ski testing on steep unsupported features. Deeper snowpack weaknesses are still on our radar, but seem to be dormant for the time being.

Problems

Wind Slabs

An icon showing Wind Slabs
Watch for pockets of reactive wind slab on steep convex shaped slopes near ridge top. Cornices could also become weak if the sun is out and temperatures warm on Wednesday.
Give cornices a wide berth when travelling on or below ridges.>Be cautious as you transition into wind affected terrain.>Travel on ridgetops to avoid wind slabs on slopes below.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Loose Wet

An icon showing Loose Wet
If the sun hangs around for one more day we could see more loose wet activity on sun-exposed slopes during the day. 
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 21st, 2015 2:00PM

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