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Avalanche Forecast

Apr 2nd, 2022–Apr 3rd, 2022
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate

Regions: South Columbia.

Westerly wind created wind slabs in lee terrain features in the alpine and treeline. These slabs are especially reactive where they overlie a crust. 

Confidence

High -

Weather Forecast

Saturday night: Clear with cloudy periods, trace of new snow, moderate southwest wind, alpine low -5 °C, freezing level at 600 m.

Sunday: Cloudy, up to 4 cm snow, moderate to strong southwest wind, alpine high -4 °C, freezing level at 1500 m. 

Monday: Cloudy, 20-25 cm snow, moderate to strong southwest wind, alpine high -4 °C, freezing level at 1500 m. 

Tuesday: Mainly cloudy, 5-10 cm snow, moderate westerly wind, alpine high -6 °C, freezing level at 1500 m.

Avalanche Summary

On Friday, small natural wet loose avalanches were observed. Skiers triggered small wind/storm slab and wet loose avalanches, as well as a large (size 2) wind slab avalanche. 

On Thursday, a few natural wind slabs up to size 2 were reported from the alpine on northeasterly slopes. Skier triggered dry loose and small storm slabs were easily triggered within the new storm snow up to size 1.5. 

On Wednesday, the recent storm snow was reactive to skier triggering, especially where it sat above a crust. Reports showed numerous dry loose and wind/storm slab avalanches size 1-2.

Snowpack Summary

15-35 cm of new snow overlies up to 20 cm of denser snow above 2100 m and tapers rapidly at lower elevations. 50-60 cm of snow now sits over the mid-March interface at upper elevations.

A melt-freeze crust exists on all aspects as high as 2100 m and to mountain top on solar aspects. Below the crust, the top 10-30 cm of the snowpack is moist. 

The early-December rain crust is approximately a metre off the ground. Reports have recently indicated that large slab avalanches have failed on this interface earlier this week following a rain and warming event. This layer may be dormant now due to colder weather, however, it may appear again during the next big warm-up or with increased load from wind, snow, and/or rain. 

Terrain and Travel

  • 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.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.

Avalanche Problems

Wind Slabs

Northwest winds have redistributed snow and formed wind slabs in lee terrain features in the alpine and treeline. 

On Sunday, moderate to strong southwest wind will form fresh wind slabs in leeward (N-NE-E) terrain features in the alpine and exposed treeline. These slabs will be most reactive where they overlie a slick crust.

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

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2