Avalanche Forecast

Issued: Mar 16th, 2020 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 Loose Wet.

Avalanche Canada JSmith, Avalanche Canada

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Lingering wind slabs below ridgetops may remain reactive to human triggers. Strong solar radiation weakens cornices and often causes them to fall onto slopes and trigger large avalanches. Pay attention to what's above your head if the sun is out.

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

Monday night: Clear, Moderate west winds, alpine low -13 C, freezing level valley bottom.

Tuesday: Sunny, light northeast winds, alpine high 2 C, freezing level 1600 m.

Wednesday: Sunny, light to moderate northwest winds, alpine high -3 C, freezing level valley bottom.

Thursday: Sunny, light west winds, alpine high -6 C, freezing level valley bottom.

Avalanche Summary

Check out this MIN of a notable avalanche reported on Monday.

Several large (size 2) wind slabs were reported on Saturday releasing naturally on lee slopes above 1700 m. 

Snowpack Summary

Strong easterly winds have drifted recent snow into wind slabs on lee terrain features in a reverse-loading pattern. 

A total of 30 to 60 cm of snow from the previous storm has been redistributed by wind or is well-settled. This snow sits over another layer of buried wind slabs in exposed areas and a sun crust on solar aspects (south through west facing slopes). Melt-freeze crusts extend up to 1900 m on other aspects. 

A thick crust/facet layer currently sits 30-60 cm below the surface. There has been only one avalanche reported on this layer since February 17th. The middle of the snowpack is generally strong, but the base of the snowpack contains weak basal facets that are most prominent in shallow rocky start zones.

Terrain and Travel

  • Stay off recently wind loaded slopes until they have had a chance to stabilize.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.

Problems

Wind Slabs

An icon showing Wind Slabs

Strong easterly winds have drifted the 10-20 cm of new snow into wind slabs on lee terrain features in a reverse loading pattern. These wind slabs may be possible to human trigger. Cornices may also be reaching their breaking point.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Rising temperatures and intense solar radiation may initiate wet loose avalanches and weaken cornices. Minimize exposure to steep, sun-exposed slopes and cornices.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Mar 17th, 2020 5:00PM