Avalanche Forecast

Issued: Jan 25th, 2020 4:00PM

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

Avalanche Canada cgarritty, Avalanche Canada

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Light new snow amounts and increasing winds will refresh our wind slab problem on Sunday. Keep seeking out sheltered snow for the safest, best quality skiing and riding.

Summary

Confidence

Moderate - Uncertainty is due to the speed, direction, or duration of the wind and its effect on the snowpack.

Weather Forecast

Saturday night: Cloudy with isolated flurries and a trace of new snow. Light south winds, increasing in the morning.

Sunday: Mainly cloudy with light flurries bringing up to 5 cm of new snow by end of day, continuing overnight. Light to moderate south or southwest winds, becoming strong at ridgetop. Alpine high temperatures around -4 with freezing levels to 1400 metres.

Monday: Cloudy with scattered flurries bringing up to 5 cm of new snow. Light south winds. Alpine high temperatures around -5.

Tuesday: Mainly cloudy with scattered flurries bringing up to 5 cm of new snow. Light south winds shifting west. Alpine high temperatures around -6.

Avalanche Summary

Reports from Friday included several new, small (size 1) storm slab releases triggered with skier traffic and ski cutting. A couple of larger (size 2) recent natural storm slabs were also noted. North aspects figured most prominently in reports. Wet loose debris from one very large (size 3.5) avalanche was also observed in the northern Monashees. It scrubbed to ground and may have started as a slab release at around 1800 metres.

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

Looking forward, now that our recent snow has formed a more reliable bond with the old surface, areas of unstable snow should become increasingly limited to recently wind loaded pockets at higher elevations.

Snowpack Summary

Regular snowfall over the past week brought about 40-80 cm of snow to the region, with the greatest accumulations focused in the Monashees. 

Elevated, mainly south winds over the same period redistributed much of this snow in the alpine and upper treeline. Warm temperatures promoted slab formation with each snowfall as well as fairly quick transitions to settlement and bonding of the new snow. Surface snow is now moist or wet from warm temperatures, wet flurries, or rain up to at least 1500 metres.

The layer of surface hoar we have been tracking since late December, now buried 90 to 170 cm deep, has gained considerable strength and is now considered dormant by professionals in the region. It remains a limited concern, potentially triggerable by large loads, in isolated areas of the Selkriks and the northern end of the Monashees. It exists primarily at treeline and just below treeline.

Terrain and Travel

  • Avoid freshly wind loaded terrain features.
  • Be alert to conditions that change with elevation, aspect and exposure to wind.

Problems

Wind Slabs

An icon showing Wind Slabs

Warm temperatures have likely helped our recent storm snow settle and bond to the surface, however thicker, more reactive wind slabs are likely to be found at higher elevations. Light flurries and moderate to strong southwest winds should give this problem a refresh on Sunday.    

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 26th, 2020 5:00PM