Avalanche Forecast

Issued: Jan 24th, 2023 4:00PM

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

Avalanche Canada jpercival, Avalanche Canada

Email

Strong winds and new snow available for wind transport maintain the current avalanche danger rating and will continue to build upon already reactive wind slabs.

Adopt a conservative terrain travel strategy that avoids steep north aspect terrain and seeks out low-angle well supported terrain.

Expected warming and the potential sun effect will encourage the surface snow to become unconsolidated, especially on steep south-aspect terrain.

Summary

Confidence

Moderate

Avalanche Summary

Monday: The south klondike highway operation reports a naturally occurring large (size 2) avalanche cycle on E through to Ne aspects in the alpine.

Sunday, A mountain information network report outlines both conditions and the observation of a naturally occurring small (size 1) avalanche. This avalanche appears to have failed near the ground and was reported to have occurred on a northeast aspect in the Fraser lakes area. See embedded MIN for pictures and review.

Saturday reports provided by the Skagway white pass avalanche control program, indicate that utilizing explosives 26kg or greater initiated numerous large avalanches (size 2 to 2.5).

Snowpack Summary

A strong southerly wind has continued to transport available new snow that has cross-loaded and created wind slabs at depths reported between 60 to 70 cm.

These new accumulations overlie an upper snowpack consisting of 15 to 30 cm of both new storm snow and unconsolidated faceted snow. The midpack presents as very dense with a reactive mid-December layer buried down between 40 to 55 cm.

Snowpack depths vary due to wind transport with averages at treeline reported as 125 cm and 200 cm in the alpine. In areas where the snowpack is less than 1 meter in depth, it is reported to be quite faceted and unconsolidated.

Weather Summary

Tuesday night

Cloudy with light snowfall, 1 to 5 cm of accumulation. Alpine temperatures are 1 °C. Ridge wind west 70 km/h. The freezing level rises to 1500 m.

Wednesday

Cloudy with light snowfall, 5 to 10 cm of accumulation. Alpine temperatures are 0 °C. Ridge wind southwest 60 km/h. The freezing level rises to 1200 m.

Thursday

Cloudy with very light snowfall, trace amounts of accumulation. Alpine temperatures drop to -2 °C. Ridge wind west becoming northwest 30 km/h. The freezing level beginning to descend from 1200 m to 0 meters by day's end.

Friday

Clearing with no new precipitation. Alpine temperatures -8 °C. Ridge wind northwest 10 km/h. The freezing level 0 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
  • Wind slabs are most reactive during their formation.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Watch for unstable snow on specific terrain features, especially when the snow is moist or wet.

Problems

Wind Slabs

An icon showing Wind Slabs

Past and continued strong southwesterly winds have encouraged rapid wind slab formation in lee areas. Assess for changing conditions throughout the day and as you gain elevation or change aspects.

Use extra caution in leeward terrain features.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

An icon showing Loose Wet

Most likely to occur on steep south-aspect terrain.

Expect even wet loose avalanches to have the potential to push a rider into or over terrain traps such as cliffs and gulley features.

Aspects: All aspects.

Elevations: Below Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Jan 25th, 2023 4:00PM