Avalanche Forecast

Issued: Mar 20th, 2021 4:00PM

The alpine rating is high, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs.

Avalanche Canada shorton, Avalanche Canada

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Avalanche danger will increase throughout the day as snow continually accumulates. Stick to mellower terrain and back off when the storm intensifies.

Summary

Confidence

Moderate - Uncertainty is due to the timing of the incoming weather system.

Weather Forecast

A cold front crossing the region Sunday will bring heavy snowfall with freezing levels staying below 1000 m.

SATURDAY NIGHT: Cloudy, light west wind, treeline temperatures drop to -4 C. 

SUNDAY: Heavy snowfall starting in the morning with 20-35 cm by the evening, 40-60 km/h south wind, treeline temperatures reach -2 C.

MONDAY: Another 15-20 cm of snow by the morning then sunny in the afternoon, 20-30 km/h west wind, treeline temperatures around -3 C.

TUESDAY: Mostly cloudy, 20-30 km/h southwest wind, treeline temperatures around -3 C.

Avalanche Summary

Avalanche control on Saturday morning produced a few small (size 1) storm slabs, but for the most part the recent snow was unreactive to ski cutting. On Sunday fresh storm slabs will grow as snow accumulates throughout the day, with natural avalanches possible during the peak of the storm in the late afternoon.

Snowpack Summary

By Sunday evening there will be another 20-35 cm of fresh snow accompanied with strong southwest wind. This will bring storm totals since Thursday to 40-70 cm, creating thick slabs. North facing slopes will have the thickest slabs due to wind loading.

Along ridgelines, cornices are large and always have the potential of failing or being triggered from the weight of a human.

Terrain and Travel

  • Travel in alpine terrain is not recommended.
  • Storm slab size and sensitivity to triggering will likely increase through the day.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Storm Slabs

An icon showing Storm Slabs

New storm slabs will rapidly grow with 20-35 cm of new snow expected to fall by Sunday evening. Human triggered avalanches will be concern on steep or wind affected slopes.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Mar 21st, 2021 4:00PM