Avalanche Forecast

Issued: Nov 13th, 2021 4:00PM

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

Kate Ryan,

Glacier.

Storm Cycle!

Even though below treeline elevations are quite shrubby, don't let that fool you!

Expect avalanches to be running into valley bottoms.

Summary

Weather Forecast

The Atmospheric River is forecast to arrive tonight!

On Sunday we could see ~60cm of new snow, with freezing levels rising to 1900m and strong to extreme winds from the SW.

Monday could see another 48cm with extreme SW gusty winds

Snowpack Summary

Recent strong winds, new snow and warm temperatures has deposited fresh storm slabs in the Alpine and exposed areas of TL. Height of snow varies significantly with elevation from ~30cm @ Rogers Pass to ~175cm in the Alpine. There are 2 prominent crusts to date, the Nov 5th buried ~40cm and the October crust lies near the base of the snowpack.

Avalanche Summary

A natural size 2.0 avalanche was observed off of Mt Cheops today. Natural activity increased Friday in the HWY corridor, and there are several MIN reports about the Cheops North path avalanches reaching down into the bushy run-outs below treeline. Avalanche activity will peak on Sunday and Monday as Rogers Pass gets hammered by the next storm.

Confidence

Freezing levels are uncertain

Problems

Storm Slabs

60cms of new snow, strong wind, and warming temperatures will create storm slabs in the Alpine and exposed areas of Treeline. Expect storm slab size and distribution to increase considerably as the storm progresses.

Use caution in lee and cross-loaded terrain near ridge crests.
Early season hazards such as rocks, trees and stumps are very prevalent

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 3

Loose Dry

Expect fast-moving loose dry in steep, confined terrain features.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Nov 14th, 2021 4:00PM