Avalanche Canada cgarritty, Avalanche Canada

Lizard Range and Flathead Avalanche Forecast

Jan 12th, 2020 4:00PM

More low density snow in the forecast means that dry loose avalanches are an increasing concern. Danger will be greatest in areas where winds move new snow into cohesive slabs. Seek sheltered snow and keep aware of wind in overhead terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Sunday night: Cloudy with increasing snowfall bringing 20-30 cm of low density new snow. Moderate south winds.

Monday: Mainly cloudy with easing flurries bringing about 5 cm of new snow. Light to moderate southwest winds. Alpine high temperatures to about -16.

Tuesday: Cloudy with scattered flurries bringing about 5 cm of new snow, increasing a bit overnight. Light to moderate southwest winds. Alpine temperatures around -18

Wednesday: Clearing. Light southwest winds. Alpine temperatures around -17.

Avalanche Summary

Reports from Saturday in the Fernie area describe widespread avalanche activity overnight and during the day, generally characterized by natural and skier triggered soft storm slabs and dry loose releases and occasionally reaching size 2.5 (large). Natural wind slab releases were suspected to be occurring at higher elevations where observations were limited by snowfall and wind.

Reports of avalanche activity over the week have been steady, with each substantial snowfall accompanied by observations of natural, skier triggered, and explosives controlled storm slabs generally reaching size 2 (large) with a few examples up to size 3 (very large). North to east aspects and higher elevations have figured most prominently in reports as a result of recent southwest winds.

Looking forward, a continuing supply of low density snow and elevated winds are expected to maintain active avalanche conditions. Avalanche danger is expected to continue to be particularly heightened in exposed areas where wind redistributes new snow into deeper and more reactive slabs.

Snowpack Summary

30-40 cm of low density new snow fell in the region over Friday night, bringing storm snow totals from last week to 70-110 cm.

This recent snow is reportedly settling rapidly, with surface instabilities generally limited to the most recent accumulations, especially where winds have redistributed snow into reactive slabs in leeward features.

Several crusts layers exist in the mid to upper snowpack as a result of recent warming and rain events. These have not been identified as bed surfaces or failure planes in recent avalanche activity.

The bottom 10-20 cm of the snowpack consists of faceted snow and decomposing crusts. Although inherently weak, this basal layer has not been an active avalanche problem in our region for several weeks.

Terrain and Travel

  • Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
  • Be alert to conditions that change with elevation and wind exposure.
  • Choose low-angled, sheltered terrain where new snow hasn't been wind-affected.

Valid until: Jan 13th, 2020 5:00PM