Avalanche Forecast

Issued: Jan 23rd, 2020 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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Another storm pulse will keep storm slab problems active on Friday. Expect avalanche danger to increase over the day as new snow accumulates.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Thursday night: Cloudy with continuing flurries bringing 5-10 cm of new snow. Light to moderate southwest winds. Freezing levels remaining near 1300 metres.

Friday: Cloudy with increasing flurries bringing about 15 cm of new snow. Light to moderate southwest winds. Alpine high temperatures around -3 with freezing levels to 1400 metres.

Saturday: Mainly cloudy with isolated flurries and a trace of new snow. Light southeast winds. Alpine high temperatures around -4 with freezing levels to 1300 metres.

Sunday: Broken skies, becoming cloudy with isolated flurries and a trace of new snow. Light southeast winds. Alpine high temperatures around -5. 

Avalanche Summary

There have been several reports over the last three days of natural, human and explosives triggered avalanches on all aspects and at all elevation bands. Most of these were size 1-1.5 storm and wind slab avalanches, with a few larger (2-2.5) cornice and explosives triggered storm slab avalanches.

On Thursday, up to 15 cm of new snow (paired with warm temperatures and strong southerly winds) likely led to touchy storm slabs forming in many areas. Similar conditions are expected for Friday.

Snowpack Summary

Regular snowfall over the past week brought around 25-50 cm of snow to the region. Elevated winds and warm temperatures on Thursday mean that touchy new storm slabs were likely forming at higher elevations while melting of surface snow occurred below about 1500 metres. A similar picture is expected for Friday.

A layer of surface hoar buried 80 to 150 cm deep could still be a concern in certain parts of the Selkriks and the northern end of the Monashees. It exists primarily at treeline and below treeline, and though it appears to be gaining strength, it could still be triggered by a large load in some areas.

Terrain and Travel

  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Avoid freshly wind loaded terrain features.

Problems

Storm Slabs

An icon showing Storm Slabs

Another period of snowfall overnight and through the day will keep storm slab problems active on Friday. Warm temperatures will likely promote slab formation in the new snow below treeline while thicker, wind-stiffened slabs continue to build at higher elevations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Jan 24th, 2020 5:00PM