Avalanche Forecast

Issued: Mar 13th, 2021 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 mconlan, Avalanche Canada

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Wind slabs are expected to develop over the day from new snow and strong wind.

Summary

Confidence

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

Weather Forecast

SATURDAY NIGHT: Increasing clouds, 40 to 60 km/h southwest wind, alpine temperature -2 C, freezing level dropping to 1500 m.

SUNDAY: Cloudy with snowfall, accumulation 5 to 15 cm with the most in the north of the region, 40 to 60 km/h southwest wind, alpine temperature -5 C, freezing level 1300 m.

MONDAY: Mix of sun and cloud, 20 km/h southeast wind, alpine temperature -5 C.

TUESDAY: Mix of sun and cloud, 20 km/h southwest wind, alpine temperature -4 C.

Avalanche Summary

A skier triggered a small wind slab in northerly terrain around 2000 m on Saturday, suspected to have formed from katabatic wind. Otherwise, loose wet activity and some cornice failures have likely occurred in the past few days from spring-like conditions. 

Looking forward, wind slabs are likely to be triggerable on Sunday as they build during the storm. Loose wet avalanche activity may continue below the rain-snow line.

Snowpack Summary

A storm will impact the region on Sunday, bringing snow above around 1300 m, and rain below. The current forecast is around 5 to 15 cm of snow with the most in the north of the region. Thicker deposits are expected in lee terrain features, as the snow will fall with strong wind. The snow will fall onto previously wet or crusty snow except at high elevation northerly aspects, where it should fall onto wind-affected snow in exposed terrain or perhaps small surface hoar crystals in sheltered terrain. Cornices have been reported as being massive and fragile.

Terrain and Travel

  • Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Extra caution is needed around cornices under the current conditions.
  • Wind slabs are most reactive during their formation.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs may form over the day from snow and strong wind. The most likely terrain to find them is on leeward, steep slopes adjacent to ridges.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

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