Avalanche Forecast

Issued: Jan 18th, 2022 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

Email

Avalanches are possible at upper elevations where wind slabs are forming.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

TUESDAY NIGHT: Clear skies, light wind from the west, treeline temperatures around -18 C.

WEDNESDAY: Increasing cloud with some light snow starting in the evening, moderate to strong wind from the southwest, treeline temperatures warming to -10 C.

THURSDAY: Moderate snowfall with 20-30 cm around Pine Pass and Torpy, 10-15 cm around McBride and Kakwa, and 5-10 cm along the eastern slopes, strong wind from the southwest, treeline temperatures warming to -3 with freezing level reaching 1300 m.

FRIDAY: Mostly cloudy, strong wind from the west, treeline temperatures around -2 C with freezing level reaching 1400 m.

Avalanche Summary

Monday's storm resulted in a natural avalanche cycle. There were numerous reports of size 1-2 storm slabs in the top 20-50 cm of new snow above 1500 m and some large size 2-3 wet loose avalanches below 1500 m. 

Snowpack Summary

Cold windy weather will blow snow into unstable slabs in lee terrain. Above 1500 m you can find 20-40 cm of settling storm snow while lower elevations will likely have crusts on the surface. The storm snow has been rapidly settling, but could potentially be slower to bond to isolated surface hoar layers in some sheltered areas, and/or thin breakable crusts below 1700 m.

A layer of faceted snow can likely be found down around 60-120 cm from the cold period at the end of December, but it has not been reactive recently and does not seem to be creating an avalanche problem in most of the region. 

The early-December crust/facet interface can typically be found down around 1 m, but has been dormant and is no longer expected to be creating an avalanche problem in the region. The base of the snowpack is composed of crusts and weak faceted grains, particularly in thin snowpack areas east of the divide. 

Terrain and Travel

  • Stay off recently wind loaded slopes until they have had a chance to stabilize.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Closely monitor how the new snow is bonding to the old surface.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent snow is stabilizing quickly in most areas, however cold windy weather will likely leave unstable wind slabs at upper elevations, especially along ridgetops.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Jan 19th, 2022 4:00PM