Avalanche Forecast

Issued: Dec 16th, 2017 5:33PM

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

mgrist, Avalanche Canada

Kootenay Boundary.

A thin cover of new snow overlies a wide variety of old surfaces. As more snow starts to accumulate, investigate how well it's bonding to the old surface before committing yourself.

Summary

Confidence

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

Weather Forecast

We'll see modest amounts of snow on Sunday, with significant wind transport from the southwest. SUNDAY: Cloudy, flurries. Accumulation 5-15 cm. Ridge wind moderate from the southwest. Temperature -6. Freezing level 600 m.MONDAY: Mostly cloudy, flurries. Accumulation 2-5 cm. Ridge wind moderate from the west. Temperature -3. Freezing level 1000 m.TUESDAY: Snow. Accumulation 15-25 cm. Ridge wind moderate southerly. Freezing level 500 m.

Avalanche Summary

No new avalanches reported.

Snowpack Summary

Approximately 5 cm of new snow has fallen on a variety of old snow surfaces, depending on aspect and elevation. On solar aspects a thin melt-freeze crust has been buried. On northerly aspects, feathery, surface hoar crystals (10-30 mm in length) have been buried below treeline as well as protected areas at treeline. In the alpine the old surface consisted of sugary snow (facets) and hard, wind scoured snow. Below the snow surface the upper snowpack is well settled and overlies a series of late-November crusts, now buried 20-50 cm and 15-25 cm thick. Recent snowpack tests have produced hard, resistant compression test results within the layers of this crust. Below the crust layer the lower snowpack is moist and well settled.

Problems

Wind Slabs

The new storm snow may be easily triggered, especially in areas where there has been additional loading from wind.

Be careful with wind loaded pockets in leeward areas, especially near ridge crests and roll-overs.Be cautious as you transition into wind affected terrain.Watch for signs of instability such as whumpfing, shooting cracks or recent natural avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Dec 17th, 2017 2:00PM