Avalanche Forecast

Issued: Dec 4th, 2021 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

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Be alert as you transition into wind-affected elevations, and stay off of recently wind loaded slopes until they've had a chance to stabilize. 

Watch for reactive slabs on all aspects, yesterday's storm snow is still settling, and changing winds may load unexpected features.

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

Saturday Night: Scattered cloud. No new snow expected. Moderate to strong northwest wind. Alpine temperature around -14 C.

Sunday: Mostly cloudy by the afternoon. No new snow expected. Moderate northwest wind. Alpine temperature around -12 C.

Monday: Clear morning, cloudy afternoon. No new snow expected. Light northeast wind, becoming moderate southwest by the evening. Alpine temperature above -10 C with a possible temperature inversion

Tuesday: Overcast. 5-20 cm snow expected. Extreme southwest winds expected at higher elevations. Freezing level rising to 250 m. Alpine temperature around -5.

Avalanche Summary

No new avalanches observed.

The few avalanches reported on Thursday in the south of the region seemed to only move the recent storm snow.

Snowpack Summary

Check out our forecaster blog here for the big picture.

The upper snowpack is variable, depending on exposure to recent strong winds. Some exposed areas may be stripped back to the Nov 30/Dec 1 Crust. 

A change in wind directions means that you may find wind slabs on many aspects, and on both sides of ridges. Late in the week, wind slabs were built by strong winds that were blowing mostly from the southwest. This weekend, the moderate to strong winds are forecast to be from the northwest.

The Nov 30/Dec 1 crust exists up to 2000 m in the southwest of the region, and may only be found up to 1200 m in areas east of Terrace.

At higher elevations where this crust is not present, the storm snow overlies old wind slab or wind stripped ridge tops.

Treeline snowpack depths are estimated to be around 2-3 m, and a prominent crust can be found near the base of the snowpack.

Terrain and Travel

  • Be alert to conditions that change with elevation and wind exposure.
  • Avoid lee and cross-loaded slopes at and above treeline.
  • Keep in mind the crust offers an excellent bed surface for avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Wind loaded features are the bigger concern right now, but lingering storm slabs may still need a day or two to settle and bond.

Slabs may be especially reactive where they sit on top of a slick crust.

Watch for wind loading on all aspects as the winds have changed directions this weekend.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Dec 5th, 2021 4:00PM