Avalanche Forecast

Issued: Feb 24th, 2021 4:00PM

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

Avalanche Canada JSmith, Avalanche Canada

Overnight snow and wind will form fresh storm slabs that are expected to become increasingly reactive throughout the day; especially in wind affected terrain. Choose very conservative terrain away from overhead hazard.

Summary

Confidence

Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system. Forecast snowfall amounts are uncertain.

Weather Forecast

  

WEDNESDAY NIGHT: Snow; 15-20 cm. / Strong, southwest ridgetop wind / Alpine low -9 / Freezing level 500 m.

THURSDAY: Snow; 10-20 cm, with another 5-10 cm. overnight / Moderate, west ridgetop wind / Alpine high -5 / Freezing level 900 m.

FRIDAY: Mostly cloudy / Light, northwest ridgetop wind / Alpine high -4 / Freezing level 1000 m.

SATURDAY: Mix of sun and cloud / Moderate, northwest ridgetop wind / Alpine high -6 / Freezing level 700 m.

Avalanche Summary

On Tuesday, a cornice fall triggered a size 2 wind slab near Whistler. Strong southwest winds have created thick wind slabs at upper elevations that may remain reactive to human triggers.

The incoming snow and strong southwest winds Wednesday night are expected to form storm slabs reactive to human triggers.

Snowpack Summary

The incoming snow and strong southwest winds Wednesday night are expected to form storm slabs reactive to human triggers on Thursday; especially in wind affected terrain.

Last weekend's storm delivered around 30 cm to the Whistler area and up to 60 cm in areas further west and south. Continued strong southwest winds have formed reactive wind slabs at treeline and above, while a rain crust has formed below 1300 m. 

The recent snow buried a variety of snow surfaces including wind pressed snow in the alpine, sun crusts on solar aspects, and a spotty layer surface hoar in some sheltered treeline areas. The kind of surface the recent snow buried will effect how long the recently formed slabs will remain reactive to human triggers.

The mid/lower snowpack is well settled and strong in most areas.

Terrain and Travel

  • Avoid all avalanche terrain during periods of heavy snowfall.
  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Expect slab conditions to change drastically as you move into wind exposed terrain.
  • Be careful to keep storm day fever from luring you out into bigger terrain features.

Problems

Storm Slabs

An icon showing Storm Slabs

New snow and wind are expected to form touchy storm slabs reactive to human triggers; especially in wind affected terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1.5 - 2.5

Valid until: Feb 25th, 2021 4:00PM