Avalanche Forecast

Issued: Jan 24th, 2023 4:00PM

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

lbaker, Avalanche Canada

Coquihalla, Harrison-Fraser, Manning, Skagit.

An above freezing layer develops in the alpine on Wednesday promoting settlement in storm snow. Watch for slab development and increasing signs of instability as temperatures penetrate the upper snowpack through the day.

Summary

Confidence

Moderate

Avalanche Summary

A few size 1 avalanches were reported within the storm snow. They were suspected to be wind triggered. Backcountry users should expect to see evidence of a natural storm slab avalanche cycle from Tuesday's surprise storm.

Please continue to share any observations or photos on the Mountain Information Network.

Snowpack Summary

30 cm of light unconsolidated snow fell Monday evening. In wind-exposed features at alpine and treeline, new snow covers old wind slabs. 30-50 cm of snow over overlies a thick supportive crust found below 2000 m.

Below this, the snowpack is considered settled. Weak layers exist within the mid and lower snowpack but the thick crusts sitting above them make triggering avalanches on these layers unlikely.

Snowpack depths are roughly 150 cm at treeline and taper rapidly below 1500 m.

Weather Summary

Tuesday Night

Cloudy with isolated flurries, trace accumulation. Westerly ridge top winds 20 km/h gusting 40 km/h. 1500m temperature high of -2C. Freezing levels of 600 m.

Wednesday

Cloudy with sunny periods. Light northwesterly winds occasionally gusting to 30 km/h. 1500m temperature high of +1C. An above freezing layer is present between 1500-2500m.

Thursday

Cloudy with sunny periods. Light northwesterly winds occasionally gusting to 40 km/h. 1500m temperature high of 0C. An above freezing layer is present between 1500-2500m during the day dropping to 800 m overnight.

5 cm of snow is forecast overnight.

Friday

Mix of sun and cloud. Light northwesterly winds occasionally gusting to 30 km/h. 1500m temperature high of -4C. Freezing levels of 1000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.
Watch for signs of slab formation throughout the day.
Watch for changing conditions today, storm slabs may become increasingly reactive.

Problems

Storm Slabs

Up to 30 cm of light unconsolidated snow fell Monday night and covered old wind slabs. Rising freezing levels Wednesday will promote cohesion in the surface snow and encourage slab development.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

30-50 cm of snow sits above a thick crust. With freezing levels well into the alpine, brief periods of direct sun could produce natural avalanches cycle on surface layers.