Avalanche Forecast

Issued: Apr 4th, 2021 4:00PM

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

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Watch for cornices and wind slabs near ridgetops and be cautious on sun-exposed slopes. 

Summary

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

SUNDAY NIGHT: Cloudy with isolated flurries bringing 2-5 cm of snow, light northeast wind, freezing level dropping to valley bottom with treeline temperatures dropping to -8 C.

MONDAY: Sunny with a few clouds, light northwest wind, treeline temperatures reach 0 C with freezing level climbing to 2100 m.

TUESDAY: Sunny, 30 km/h southwest wind, treeline temperatures reach 0 C with freezing level climbing to 2200 m.

WEDNESDAY: Increasing cloud and some light afternoon flurries, 40-50 km/h southwest wind, freezing level around 2000 m.

Avalanche Summary

The last reported avalanche activity was on Thursday when some small wet loose avalanches on steep sun-exposed slopes.

Snowpack Summary

5-15 cm of heavy powder is sitting above crusts on all but north facing terrain at upper elevations. Some small wind slabs may be found on lee features below alpine ridgetops. Cornices are large, looming, and capable of triggering avalanches when they fail.

The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack. 

Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.

Terrain and Travel

  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Carefully evaluate steep lines for wind slabs.
  • Be alert to conditions that change with elevation and sun exposure.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Wind Slabs

An icon showing Wind Slabs

Convective flurries and southwesterly winds on Sunday may form small wind slabs sitting on slippery crusts on lee features below alpine ridgetops.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Cornices

An icon showing Cornices

Cornices are large and looming along many ridgelines. They are capable of triggering large avalanches when they fail.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1.5 - 2.5

Valid until: Apr 5th, 2021 4:00PM