Avalanche Forecast

Issued: Jan 25th, 2016 9:04AM

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

jlammers, Avalanche Canada

Northwest Inland.

Watch for fresh wind slab development on Tuesday.

Summary

Confidence

Low - Forecast snowfall amounts are uncertain on Wednesday

Weather Forecast

5-10cm of new snow and extreme southwest winds are expected on Tuesday. Trace amounts of new snow and moderate winds are forecast for Wednesday and Thursday. Freezing levels will hover around 1500m on Tuesday, drop to about 1000m on Wednesday and then rise back to 1400m by Thursday.

Avalanche Summary

There are very few recent observations from the region. A couple natural size 2 slab avalanches were observed in wind-loaded terrain (N-NE aspects) at around 1800 m on Friday. Light amounts of new snow and extreme southwest winds are likely to spark a new round of wind slab activity on Tuesday.

Snowpack Summary

Fresh and reactive wind slabs could be found in lee and cross-loaded features. There is a notable persistent weakness of buried surface hoar in many places, generally found between 30 and 60 cm deep. Wind, sunshine, and milder temperatures could help promote slab development in the snow overlying this interface. Stay tuned to signs of instability like recent avalanches, whumpfing, and shooting cracks. The mid pack that was reported to be well settled may have now facetted in the shallower areas, and the deeper basal layers are almost certainly facetted and weak.

Problems

Wind Slabs

Light amounts of new snow and extreme southwest winds are expected to create fresh and reactive wind slabs on Tuesday.

Choose well supported terrain without convexities.>Be cautious as you transition into wind affected terrain. >

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

New snow has been slowly accumulating over a layer of facets and surface hoar and may now be primed for triggering in some areas.

Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.>Watch for whumpfing, hollow sounds, shooting cracks or recent avalanches.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 3

Valid until: Jan 26th, 2016 2:00PM