Avalanche Forecast

Issued: Dec 20th, 2016 5:25PM

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

mbender, Avalanche Canada

Kootenay Boundary.

The wind is forecast to be strong Tuesday night into Wednesday. Plenty of new snow to redistribute into new wind slabs at tree line and alpine elevations

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Wednesday: Isolated flurriesÂ / Moderate southwest wind / Alpine temperature -7Thursday: Scattered Flurries, accumulation 5cm / Moderate southwest wind / Alpine temperature -6 Friday: Flurries, accumulation 5-10cm / Light to moderate south wind / Alpine temperature -6

Avalanche Summary

Recent reports indicate avalanche activity from explosives control running on the storm snow old snow interface to size 2 at treeline and above. These are reported as both storm slab and wind slab avalanches.

Snowpack Summary

20-40 cm of new snow has buried previously formed windslabs, facets and surface hoar. Moderate to strong winds have loaded leeward features with new touchy wind slabs. A widespread crust that was buried in November is typically down 80-100cm. Recent tests show variable results with this persistent weakness. Some show results as hard and resistant and other show it may have the propensity to propagate large avalanches if triggered from thin rocky areas.

Problems

Storm Slabs

20-40 cm of new snow sits on top of a variety of potential weak sliding surfaces

Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.Use caution above cliffs and terrain traps where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

New snow combined with moderate to strong southwest winds have created slabs in the lee of terrain features

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 21st, 2016 2:00PM