Avalanche Forecast

Issued: Mar 22nd, 2020 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

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Human triggered avalanches will be likely on Monday with new snow and wind in the forecast. Keep your risk tolerance to a minimum while public health resources are strained.

Summary

Confidence

Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather. Forecast snowfall amounts are uncertain.

Weather Forecast

A cold front crosses the region Monday morning.

SUNDAY NIGHT: 5-10 cm of new snow, moderate southwest wind, freezing level drops to 700 m, treeline temperatures drop to -3 C.

MONDAY: Another 10-15 cm of snow throughout the day, light to moderate southwest wind, freezing level around 700 m, treeline temperatures reach -1 C.

TUESDAY: Mix of sun and cloud, light wind, freezing level around 700 m, treeline temperatures reach -1 C.

WEDNESDAY: Mix of sun and clouds, light northwest wind, freezing level around 900 m, treeline temperatures reach 0 C.

Avalanche Summary

Human triggered slab avalanches will be a concern on slopes that accumulate new snow, especially in wind loaded terrain.

No avalanches have been reported the past few days, although warm temperatures have likely resulted in natural wet loose avalanches in steep south-facing terrain. We have a preliminary report of a snowshoer who was recently fatally involved in an avalanche in the Mt. Brunswick area. The individual was recovered on March 20, three days after being reported missing and six days after beginning their trip. The avalanche was a 45-100 cm deep wind slab release on steep terrain and it buried a trail 50-60 m below it. Given snowpack changes since the likely date of this incident, similar avalanches are not expected to occur going forward.

Snowpack Summary

The past week of warm weather has formed moist and crusty surfaces which will be buried by 15-30 cm of new snow by Monday afternoon. There is some uncertainty about how well the new snow will bond to these interfaces. A few high elevation, shaded slopes may still hold dry, previously wind-affected snow.

The snowpack is well-settled. Snowpack depths diminish rapidly with elevation, with 300-400 cm at treeline and no snow below 700 m.

Terrain and Travel

  • Watch for fresh storm slabs building throughout the day.
  • Stick to well supported, lower angle terrain.

Problems

Wind Slabs

An icon showing Wind Slabs

New snow will form reactive slabs on steep terrain throughout the region. There is uncertainty about how well these slabs will bond to underlying interfaces.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Mar 23rd, 2020 4:00PM