Avalanche Forecast

Issued: Nov 15th, 2020 4:20PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is below threshold. Known problems include Wind Slabs and Loose Dry.

Tim Haggarty,

Recent winds and snow have increased the hazard with the development of wind slabs extending down to treeline.  After a brief break early Monday another storm arrives that will likely keep hazard elevated.

Summary

Weather Forecast

Alpine winds will diminish to light  Monday and shift W with a bit of clearing.  A warm front will arrive late in the day with winds increasing to strong in the alpine, shifting S,  and temperatures rising. Further warming is expected Tuesday and may include solar influence midday before more precip arrives - some potentially as rain.

Snowpack Summary

Up to 25m of snow in the past 48hrs. Moderate South and West winds are building wind slabs. The early Nov crusts exist up to 2400m in the Icefields Parkway area up to 2700m in the Sunshine area. This crust is up to 10cm thick and found 20-40cm above the ground. At tree line the snowpack is 40-100cm with very little snow found below 2200m.

Avalanche Summary

Snowfall favored the southern areas of the region with SSV reporting rapid loading and wind slab development at treeline. Ski cutting produced sz 1 slabs at treeline and explosive control in the Delirium area triggered fresh cornice growth and likely slabs in the alpine (poor visibility). Lake Louise saw activity diminish today with less snowfall.

Confidence

Due to the number of field observations

Problems

Wind Slabs

An icon showing Wind Slabs

Slab development continued today in the alpine increasing potential size and distribution. Development also crept into treeline where avalanches hold the potential to run faster and farther over the existing crusts.

  • Be careful around wind loaded areas near ridge crests, cross loaded gullies and roll-overs.
  • Be careful with wind loaded pockets while approaching and climbing ice routes.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Dry

An icon showing Loose Dry

Recent snowfall and winds have loaded sheltered faces and gullies. These sluffs are mainly a concern in steep confined terrain that can focus avalanche flow or where a small sluff could push you over a cliff's edge or into a terrain trap.

  • 875
  • If triggered dry loose point releases can form deeper deposits in terrain traps.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Nov 16th, 2020 4:00PM