Avalanche Forecast

Issued: Jan 20th, 2015 7:51AM

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

Peter, Avalanche Canada

Northwest Inland.

We're in for a stormy week but it's hard to say how much snow or rain will make it inland. Avalanche danger could bump to high if you receive more than 30 cm of snow or it's raining steadily.

Summary

Confidence

Fair - Forecast snowfall amounts are uncertain

Weather Forecast

Synopsis: The storm track is aimed squarely at the Northwest this week. Weâ€™re certain to see some spillover into inland sections but the brunt will be felt right along the coast. Expect 10-20 mm of precipitation each day with the heaviest amounts possible on Friday. The freezing level should be gradually climbing to between 1500 and 1700 m. Winds are strong from the SW throughout the week.

Avalanche Summary

There were no new observations on Monday. A couple size natural size 2 wind slabs were reported from steep wind loaded terrain (northeast facing) on Sunday. Avalanche activity will probably be on the rise over the next few days with wet activity at lower elevations and wind and storm slabs above 1500 m.

Snowpack Summary

Strong southerly winds are building wind slabs, generally depositing snow on NW-NE aspects (other aspects may be getting cross-loaded or variable local wind effects too, so keep your eyes open). A surface hoar layer was reported to have been buried at the start of January in the northern part of the region. This may be around 20-40 cm deep now. In the mid-pack, a crust weakness buried in mid-December seems to have fallen off most operators' radar for now. Near the base of the snowpack is a November crust-facet combination that could remain problematic, especially in shallower snowpack areas with heavy loading and warming this week.

Problems

Wind Slabs

Forecast snowfall amounts could vary throughout the region but strong SW winds look pretty certain everywhere. Expect deep wind slabs to form in exposed lee and cross-loaded terrain.

Choose well supported terrain without convexities.>Use ridges or ribs to avoid pockets of wind loaded snow.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 4

Deep Persistent Slabs

Deep persistent weaknesses could wake up with loading from snow, rain, or wind this week. We could see isolated very large and deep slabs.

Be aware of the potential for large, deep avalanches.>Use caution around convexities, ridge crests, rock outcroppings and anywhere else with a thin or variable snowpack.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

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