Avalanche Forecast

Issued: Mar 20th, 2022 4:00PM

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

Avalanche Canada TRettie, Avalanche Canada

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Carefully assess the wind slab hazard as you move through terrain. New wind slabs could build through the day.

Summary

Confidence

Moderate - The snowpack structure is generally well understood.

Weather Forecast

Sunday night: 5 to 15 cm of new snow expected with strong southwest winds. Low of -2 at 1500 m.

Monday: cloudy with 5 to 10 cm of new snow expected. Moderate to strong southwest winds and freezing levels rising to 1500 m. 

Tuesday: cloudy with flurries bringing 5 cm of new snow with strong southwest winds. Freezing levels rising to 2000 m.

Wednesday: cloudy with around 5 cm of new snow expected. Strong southwest winds in the morning and light in the evening. Freezing level aaround 1900 m.

Avalanche Summary

On Saturday ski cutting and explosive control produced storm and wind slab avalanches up to size 1.5. These avalanches were generally in the immediate lee of ridge features at treeline and above. Several small cornice failures were also reported.

Snowpack Summary

Wind slabs can be found on north and east aspects at treeline and above. south facing slopes are pressed or scoured in the alpine. Moist snow could be observed at lower elevations.

30 to 90 cm overlies the mid March layer. This layer presents as surface hoar in shady, wind-sheltered areas and a hard melt-freeze crust on all aspects below 1700 m and on sun-exposed slopes into the alpine.  

Over one meter deep, a layer of facets may be found above a melt-freeze crust that formed in February. This layer had been most reactive on north and northeast aspects between 1600 and 2100 m. This layer is currently considered dormant. 

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Problems

Wind Slabs

An icon showing Wind Slabs

New wind slabs can be found on North and East aspects in exposed treeline and alpine terrain. Strong winds in the alpine mean that wind slab could be found further down slope than expected.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Cornices

An icon showing Cornices

Fragile cornices have been reported recently. Give cornices a wide berth when traveling on or below ridges. 

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Mar 21st, 2022 4:00PM