Avalanche Forecast

Issued: Feb 1st, 2023 4:00PM

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

Avalanche Canada lbaker, Avalanche Canada

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Watch for isolated pockets of fresh windslab on north and east facing slopes in the alpine, especially just below ridgetops and in extreme and steep terrain.

Summary

Confidence

High

Avalanche Summary

No significant avalanches were reported over the last few days. The last notable avalanche activity was at the end of last week, when several wind slabs avalanches were reported during a period of northerly wind. Riders should continue to be cautious around isolated pockets of wind slabs at treeline and alpine elevations.

If you head to the backcountry please post your reports and photos to the Mountain Information Network, the information is very helpful to forecasters.

Snowpack Summary

5 to 15 cm of soft snow overlies a mix of crusts and hard wind-affected snow. This week variable winds have affected all exposed areas at alpine and treeline, scouring slopes and creating pockets of stiff wind slabs. A thin breakable crust can be found at or near the surface on all aspects at treeline and above. This crust is thick and supportive below treeline and on steep solar aspects.

A crust from mid-January can be found down 40 to 70 cm deep. A number of weak layers exist within the middle and lower snowpack, but the thick crusts sitting above them make triggering avalanches on these layers unlikely. The areas of concern in terms of triggering a deeper layer are shallow rocky areas.

Weather Summary

Wednesday night

Cloudy with isolated flurries, trace accumulation. Southwest ridgetop winds 30 to 40 km/h. Treeline temperatures -5 ˚C. Freezing levels 700 m.

Thursday

Mix of sun and cloud with cloud increasing in the afternoon. Southerly ridgetop winds 30 to 50 km/h. Treeline temperatures -3 ˚C. Freezing levels 1200 m.

Isolated flurries overnight 2-5 cm.

Friday

Mainly cloudy with flurries, 10 cm accumulation. Southerly ridgetop winds 40 to 60 km/h. Treeline temperatures -2 ˚C. Freezing levels 1400 m.

Overnight storm increases in intensity. 15 to 30 cm of snow is expected overnight. 40 to 70 km/h south wind, treeline temperatures warm to -3 ˚C.

Saturday

The storm continues with cloudy skies and flurries, 10-15 cm accumulation. 40 to 60 km/h south wind, treeline temperatures warm to -2 ˚C. Freezing levels 1400 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
  • Although their spatial distribution is isolated, wind slabs are reactive.
  • Approach lee and cross-loaded slopes with caution.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Wind Slabs

An icon showing Wind Slabs

Moderate gusting to strong southwesterly winds are forming new wind slabs on north and east-facing slopes, while previous outflow winds have left stiff wind slabs on south and west-facing slopes. These slabs may be more reactive where they overlie a hard crust layer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2023 4:00PM