Avalanche Forecast

Issued: Jan 28th, 2024 4:00PM

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

Avalanche Canada mhalik, Avalanche Canada

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Avoid avalanche terrain today. Heavy snow/rain, extreme wind and warm temperatures have made an unstable snowpack, with potential for widespread large avalanches.

Summary

Confidence

Moderate

Avalanche Summary

Saturday: A naturally triggered avalanche cycle consisting of both slab and loose wet avalanches to size 2.5 was observed along the highway corridor between White Pass and Skagway. These avalanches all occurred on northerly aspects.

We suspect a widespread natural avalanche cycle is ongoing across the region.

Snowpack Summary

Around 25-30 cm of storm snow has fallen recently, with more set to fall overnight Sunday and throughout the day Monday.

At lower elevations, some of this precipitation fell as rain. The new snow is likely to be dense and settling rapidly with the warm temperatures and may be moist or wet below 1700m.

At upper elevations, strong southerly alpine winds have likely formed touchy slabs on lee northerly and easterly slopes.

A buried weak layer of surface hoar and facets has been found in isolated locations 45-70 cm below the surface. There is potential for the new precipitation and warm temperatures to overload this layer triggering large avalanches.

Weather Summary

Sunday Night

Cloudy with 15-30 cm of new snow / heavy rain, southeast alpine wind 60 km/h, treeline temperature 4°C, freezing levels potentially rising to 1700 m

Monday

Cloudy with 10-20 cm of new snow / moderate to heavy rain, south alpine wind 70 km/h, treeline temperature 2°C, freezing level 1500 m.

Tuesday

Cloudy with 5-10 cm of new snow, southwest alpine wind 40 km/h, treeline temperature 0°C dropping to -10°C, freezing levels dropping from 1000 m back to 0 m

Wednesday

Mostly sunny, with no new snow, northeast alpine wind 20-40 km/h, treeline temperature -10°C

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid all avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • Use increased caution at all elevations. Storm snow is forming touchy slabs.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Storm slabs have built up throughout the storm and are primed to be very reactive to natural and human triggers.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2.5

Valid until: Jan 29th, 2024 4:00PM