Avalanche Forecast

Issued: Mar 29th, 2022 4:00PM

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

Avalanche Canada zryan, Avalanche Canada

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Fresh wind slabs are expected to form throughout the day. These slabs will be most reactive where they overlie a slick crust.

Loose wet avalanches are possible at lower elevations if the surface remains wet and unconsolidated.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

TUESDAY NIGHT: Increasing cloud cover. 20-40 km/h southwest winds. Freezing level dropping to 1000 m.

WEDNESDAY: Snowing, 5-10 cm of accumulation. 25-40 km/h southwest winds. Freezing level around 1500 m.

THURSDAY: Cloudy with light snowfall. 15-40 km/h west winds. Freezing level around 1400 m.

FRIDAY: Cloudy with light flurries. 20-40 km/h southwest winds. Freezing level around 1500 m.

Avalanche Summary

A widespread wet loose natural avalanche cycle up to size 3 occurred on Monday on all aspects and elevations. The most activity occurred below treeline. Similar activity is not expected on Wednesday with cooling temperatures and cloud cover.

Several natural and human-triggered storm slabs were reported in the north of the region on Monday. These slabs occurred on northeast aspects in the alpine and treeline (size 1-2).

The last persistent slab avalanche in the region was on March 26th. This size 2 avalanche was remote-triggered, meaning the skier was a distance away from where the avalanche failed. It was in a wind-loaded area at treeline on a southeast aspect. This layer is expected to become dormant after being tested by significant warming followed by cooling temperatures. 

Snowpack Summary

5-15 cm of new snow overlies up to 30 cm of heavier snow that tapers rapidly with elevation. Westerly wind may form pockets of windslab in the alpine and exposed treeline. A refrozen crust can be found below the new snow on all aspects as high as 2300 m. This crust is expected to break down throughout the day at low elevations with rain and warm temperatures. Below the crust, the top 10-30 cm of the snowpack is moist.

Several other crust layers exist in the upper snowpack, that have shown no recent reactivity. The remainder of the snowpack is well-bonded.

Terrain and Travel

  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Wind slabs may be poorly bonded to the underlying crust.
  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

Wind slabs may be found in steep, lee terrain features in the alpine and exposed treeline. These wind slabs will be most reactive where they overlie a slick crust.  

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

A poor overnight crust recovery followed by above freezing temperatures and rain at lower elevations may cause wet loose avalanches out of steep terrain. Watch for wet and heavy surface conditions. 

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Mar 30th, 2022 4:00PM