Avalanche Forecast

Issued: Nov 27th, 2017 4:52PM

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

jfloyer, Avalanche Canada

South Coast Inland.

This forecast is based on limited information. Snow amounts are also uncertain. Treat this as a first estimation of avalanche danger and be prepared to adjust your decisions based on observed conditions.

Summary

Confidence

Low - Intensity of incoming weather systems is uncertain

Weather Forecast

Allison Pass (1340m):32mm on Sunday. Rain becomming snow 10pm Sunday with approx 5cm snow at end of storm.Coquihalla Summit (1230m):25mm precip Sunday. Temps becoming negative at 4pm. Suspect about 10cm new snow.Little Bear (1660m): 20cm snow at end of storm overnight stopping 5am this morning.Great Bear (1710m): Winds 20-30 SW to SE during storm, diminishing to 10 SECayoosh Summit (1350m):30mm Rain on Sunday with 2cm snow at end of storm.Blowdown Mid (1890m):32mm precip/8cm snow; TPres -7Blowdown Peak (2320m): During storm 30-50 S and SW; Recent 20-25 W

Avalanche Summary

There was a natural avalanche cycle on Sunday. On Monday no activity was reported. On Tuesday, I'm expecting mostly small wind slab avalanches in exposed terrain.

Snowpack Summary

Recent heavy rain saturated the upper snowpack at all elevations before depositing 10-20 cm of new snow at higher elevations on Sunday morning. Below any new snow accumulations, the previously rain-soaked upper snow has formed a crust, reported to be thick (15 cm) below treeline and thin (2cm) in the alpine. Treeline snow depths are approximately 90 cm throughout the region.

Problems

Wind Slabs

Wind slab avalanches are expected to form in response to loading from new snow and wind. The new snow may not bond well to the underlying crust.

Use increased caution in lee areas. Recent snowfall and wind loading have created wind slabs.The new snow will require several days to settle and stabilize.

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

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Nov 28th, 2017 2:00PM