Avalanche Forecast

Issued: Dec 28th, 2019 4:30PM

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

Avalanche Canada astclair, Avalanche Canada

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20-30 cm of new snow in the last 48 hours has created a storm slab problem to manage on Sunday. The recent snow is not expected to bond well with pre-existing snow surfaces, and thicker, more reactive slabs may form as temperatures increase.

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

Saturday night: Cloudy with scattered wet flurries accumulating 5-10 cm. Light southwest winds. Alpine temperatures near 0 C with freezing level rising to 1500 meters overnight.

Sunday: Mostly cloudy with scattered wet flurries with a trace of accumulation or possible light rain. Light southeast winds. Alpine high temperatures around 4 C with freezing level to 1900 meters.

Monday: Mostly cloudy, light southwest winds, alpine high temperatures around 3 C with freezing level dropping from 1800 meters.

Tuesday: Cloudy, 15-30 cm of snow, moderate southwest winds, alpine high temperatures near 2 C with freezing level around 1000 meters.

Avalanche Summary

No new avalanches have been reported in the region since the widespread natural avalanche cycle brought on by last weekend's storm.

The recent snow and warming temperatures present a storm slab problem to manage on Sunday, as warmer temperatures increase slab properties.

Snowpack Summary

20-25 cm of recent snow fell on a mix of crusts or old snow surfaces that are not likely to bond well. In areas where snow accumulations are deeper, this new layer may form a cohesive slab with the potential to slide.

Above 1200 meters, 50-100 cm of snow from last weekend comprises the upper snowpack. This storm snow is well settled with a strong bond to the previous surface. Below 1200 meters, the snowpack diminishes rapidly with elevation.

Terrain and Travel

  • Use small low consequence slopes to test the bond of the new snow.
  • Dial back your terrain choices if you are seeing more than 20 cm of new snow.
  • The more the snowpack warms-up and weakens, the more conservative you`ll want to be with your terrain selection.

Problems

Storm Slabs

An icon showing Storm Slabs

20-30 cm of new snow presents a storm slab problem to manage on Sunday, as the latest snow is not expected to bond well with the pre-existing snow surfaces. Thicker, more reactive slabs are expected to form as temperatures increase.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Loose Wet

An icon showing Loose Wet

Warming temperatures and light rain at lower elevations are likely to produce wet loose activity in the surface snow. These point releases are expected to be small but could have greater consequences in areas where terrain traps exist.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Dec 29th, 2019 5:00PM