Avalanche Forecast

Issued: Jan 25th, 2023 4:00PM

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

Avalanche Canada PW, Avalanche Canada

Email

Strong winds Thursday will create fresh windslabs at alpine and treeline locations.

Summary

Confidence

Moderate

Avalanche Summary

Sunshine and Lake Louise ski hill reported isolated, small skier controlled avalanches in wind loaded alpine terrain features.

Snowpack Summary

Recent moderate to strong winds have created windslabs in the alpine. Below this, the upper snowpack contains weak layers 10-30 cm deep (Jan. 4th) and 25-50 cm deep (Dec. 17th) that are generally unreactive. The Nov 16 deep persistent layer is down 40-90 cm and continues to produce sudden results in test profiles. In areas west of the divide, these layers are generally deeper and more spread apart in the snowpack.

Weather Summary

A NW flow will bring windy conditions with light flurries and warm temps on Thursday. Friday could see upwards of 10cm of snow and cooling temps as a NE flow arrives. Winds will taper and Saturday will be cold and slightly overcast.

Thurs: Alpine winds extreme from the NW. Alpine high temp ~ -4, low -8.

Fri: 5-10 cm of snow through the day. Alpine winds moderate to strong, switching to NE. Temperatures cooling to -15.

Sat: Cold and partially cloudy, daytime high of -25 in the alpine.

Terrain and Travel Advice

  • Uncertainty is best managed through conservative terrain choices at this time.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

The lower snowpack is comprised of weak facets and depth hoar with the upper snowpack forming a 40 to 90 cm thick slab above. This weak basal layer is uniform across most of the forecast region and has been responsible for most of the larger avalanche activity this season.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Wind Slabs

An icon showing Wind Slabs

Strong to extreme NW winds on Thursday have formed wind slabs in lees features of the alpine and treeline elevations.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 1.5

Valid until: Jan 26th, 2023 4:00PM