Avalanche Forecast

Issued: Jan 22nd, 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 kdevine, Avalanche Canada

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Fresh storm slabs will likely be reactive to human triggering, especially in wind loaded areas, and at upper elevations. Watch for signs of instability such as whumphing, cracking and recent avalanches.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

WEDNESDAY NIGHT - Mainly cloudy with scattered flurries / southwest wind, 20-40 km/h / alpine low temperature near -6

THURSDAY - Flurries, 10-15 cm / southwest wind, 30-50 km/h / alpine high temperature near -1 / freezing level 1500 m

FRIDAY - Flurries, 5-10 cm / southwest wind, 20-30 km/h / alpine high temperature near -1 / freezing level 1500 m

SATURDAY - Mainly cloudy with scattered flurries, up to 5 cm / southwest wind, 20-30 km/h / alpine high temperature near -3 / freezing level 1400 m

Avalanche Summary

There have been several reports over the past three days of natural, human and explosives triggered avalanches. Most of these were size 1-1.5 storm and wind slab avalanches, on northerly aspects in the alpine and at treeline.

Two notable persistent slab avalanches were reported on Tuesday, one natural and one explosives triggered, size 2.5 and 3.5 respectively. Both of these avalanches occurred in the alpine, on northerly aspects.

Snowpack Summary

Over the past week there has been about 15 to 30 cm of recent snow, and another 10-15 is forecast for Thursday. This snow will arrive with strong southwest winds and relatively warm temperatures, which will mean that storm slabs will likely be forming in many areas.

A layer of surface hoar may still be found roughly 80-120 cm deep in the Selkirks and 120-160 cm deep in the Monashees. This layer exists primarily at treeline and below treeline and through it appears to be gaining strength, it could still be triggered by a large load in some areas.

A weak facet/crust layer from late November may be found near the bottom of the snowpack.

Terrain and Travel

  • Watch for changing conditions today, storm slabs may become increasingly reactive.
  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.

Problems

Storm Slabs

An icon showing Storm Slabs

With 10-15 cm of snow with strong winds and warm temperatures forecast for Thursday, new storm slabs will be forming in many areas. These slabs may become increasingly reactive throughout the day.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Jan 23rd, 2020 5:00PM