Avalanche Forecast

Issued: Feb 28th, 2022 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

Triggering avalanches is likely on freshly wind loaded slopes. Seek out sheltered terrain.

Summary

Confidence

Moderate - Uncertainty is due to the track & intensity of the incoming weather system.

Weather Forecast

MONDAY NIGHT: Cloudy with isolated flurries and up to 5 cm of new snow, moderate wind from the southwest, treeline temperatures around -6 C.

TUESDAY: Cloudy with scattered flurries bringing 5 cm of snow to most parts of the region but up to 15 cm in localized areas, light to moderate wind from the southwest, treeline temperatures around -6 C with freezing level climbing to 1200 m around the McGregors (and cooler elsewhere).

WEDNESDAY: Mix of sun and cloud with some isolated flurries bringing trace amounts of snow, light wind from the south, treeline temperatures around -6 C.

THURSDAY: Mix of sun and cloud, light wind from the northwest, treeline temperatures around -8 C.

Avalanche Summary

Over the weekend there were a few small (size 1) human triggered wind slab avalanches. These were roughly 20 cm thick and ran on crust layers. See the avalanche photo from the North Rockies field team at Hasler. The addition of more snow since then has increased the potential size of wind slab avalanches.

Snowpack Summary

Flurries throughout the day on Tuesday will bring recent storm totals to 15 to 25 cm of fresh snow. This snow covers a wide variety of hard surfaces, including heavily wind-affected snow on alpine slopes and a sun crust on steep south-facing slopes. These hard layers remain on the surface on some wind exposed features. There have been some isolated observations of weak faceted snow or surface hoar crystals buried 50 to 100 cm deep, but they have not been a concern due to the several crusts and hard layers above them. The base of the snowpack could be weak and faceted in shallow, rocky slopes east of the divide.

Terrain and Travel

  • Be carefull around freshly wind loaded features.
  • Wind slabs are most reactive during their formation.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Closely monitor how the new snow is bonding to the crust.

Problems

Wind Slabs

An icon showing Wind Slabs

Steady wind will redistribute fresh snow (15-25 cm) and build reactive wind slabs on any exposed terrain, lee features, and around ridgelines. Use increased caution around treeline or alpine features where these slabs may overlay weak snow, sun crusts, or hard wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 1st, 2022 4:00PM