Avalanche Forecast

Issued: Mar 18th, 2021 4:00PM

The alpine rating is low, the treeline rating is low, and the below treeline rating is low.

Avalanche Canada cgarritty, Avalanche Canada

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A cooling trend should have a strong stabilizing effect on the snowpack in the coming days. 

Summary

Confidence

Moderate -

Weather Forecast

Thursday night: Becoming cloudy. Moderate to strong southwest winds, potentially extreme in the alpine. Freezing levels remaining near 2000 metres.

Friday: Mainly cloudy with scattered wet flurries with a trace to 5 cm of new snow at higher elevations. Light rain below around 1700 metres. Moderate to strong southwest winds, potentially extreme in the alpine. Alpine high temperatures around 0 with freezing levels to 2000 metres.

Saturday: Mainly cloudy with isolated flurries. Moderate to strong southwest winds. Alpine high temperatures around -4 with freezing levels to 1700 metres.

Sunday: Cloudy with isolated flurries. Light to moderate southwest winds. Alpine high temperatures around -4.

Avalanche Summary

No new avalanches were reported on Tuesday or Wednesday.

On Monday there were size 1 wet loose avalanches reported in the backcountry near Castle. There were wet loose avalanches size 1-2 from throughout the region out of southerly alpine terrain reported over the weekend. 

Looking forward, light forecast snow amounts are not expected to be sufficient to form a new wind slab problem. Small wet loose avalanches may be an issue in the limited areas rain falls on dry snow that hasn't already experienced multiple melt-freeze cycles.

Snowpack Summary

Forecast snow and rain will bring a bit of elevation-dependent change to the snow surface on Friday, with a dusting of new snow over wind-affected surfaces expected in the alpine, transitioning to wet flurries and a rain-wetted surface below about 1700 metres.

Reports in advance of our forecast precipitation suggest snow on northerly terrain above 1600 m has so far remained dry. Cornices are large and looming, and glide cracks are increasing in size. Both should be considered unpredictable and given a wide berth.

Around 30 to 60 cm of snow sits above a layer of sugary faceted grains that were buried in mid-February. In some areas, there may be an old layer of feathery surface hoar or facets from late January down 50 to 80 cm deep. There have been no reported avalanches on either of these layers in the region since March 9th in the Crowsnest, but there is always lingering concern that heat added to the snowpack (now from forecast rain) could increase the reactivity of deeper weak layers in isolated areas.

The mid pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack. 

Terrain and Travel

  • Be alert to conditions that change with elevation.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Valid until: Mar 19th, 2021 4:00PM