Avalanche Forecast

Issued: Feb 10th, 2022 4:00PM

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

Avalanche Canada bchristie, Avalanche Canada

Email

Be conservative with your terrain choices. Recent, warm, stormy weather brought rapid change to the snowpack, and freezing levels are forecasted to rise again. Variable surface conditions have made mountain travel challenging.

Summary

Confidence

Moderate - Uncertainty is due to rapidly fluctuating freezing levels.

Weather Forecast

Warm air from the incoming front will ride on top of colder air, making for a wide variety of freezing levels across the region for Friday.

THURSDAY NIGHT: Mostly clear. No new snow expected. Light to moderate northwest wind. Freezing level rising to 2000 m around Terrace and Kitimat. Staying near valley bottom north of Terrace. 

FRIDAY: Mostly sunny. No new snow expected. Moderate west wind. Freezing levels up to 2000 m around Terrace and Kitimat. Rising to 500 m north of Terrace. 

SATURDAY: Partly cloudy by the afternoon. Light snow/rain expected. Moderate to strong west wind. Freezing levels around 2000 m.

SUNDAY: Mostly cloudy. Light snow/rain expected. Light south wind. Freezing levels falling to 1000 m by the afternoon.

Avalanche Summary

Most new avalanche observations from Thursday likely occured during the storm on Wednesday.

On Wednesday, heavy precipitation, rising freezing levels, and strong wind caused a widespread natural avalanche cycle. The largest reported were size 4 in Bear Pass, with avalanches starting as storm or wind slabs and stepping down to old weak layers from January and December in some cases. Most other avalanches reported were wet loose, or wet slabs. Many professional operators were reporting natural avalanches running full path to valley bottom. An exception is around Shames where avalanches were still large, but stopping mid-track.

Snowpack Summary

A wet, warm, rainy storm on Wednesday soaked the upper snowpack up to mountaintop in the southern half of the region. Freezing levels dropped to around 1000 m on Thursday, and they'll vary across the region on Friday (ranging from valley bottom in the north end of the region, to 2000 m in the south). You may find a solid, supportive crust, a breakable crust over moist snow, or loose, wet snow. Prepare for challenging travel conditions, either slide-for-life, or super grabby.

At higher elevations that did not see much rain, expect the new snow to have formed reactive windslabs in lee terrain due to consistently strong south through west winds. 

Down 60-100 cm, you may find a weak layer of surface hoar crystals, particularly around treeline elevations in terrain features sheltered from the wind. This layer may be found immediately above a hard melt-freeze crust.

Deeper in the snowpack, another surface hoar layer from mid-January may be found around 80 to 120 cm deep at higher elevations in sheltered terrain. This layer is most problematic where it overlies a hard melt-freeze crust.

Terrain and Travel

  • When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
  • A crust on the surface will help bind the snow together, but may make for tough travel conditions.
  • Be alert to conditions that change with elevation and sun exposure.
  • Although their spatial distribution is isolated, wind slabs are reactive.
  • Recent wind has varied in direction so watch for wind slabs on all aspects.

Problems

Wind Slabs

An icon showing Wind Slabs

Terrain that didn't get rained on during Wednesday's storm has the potential to have received large amounts of snow with consistently strong wind. 

If the snow seems soft and dry, watch out for signs of instability like shooting cracks, or hollow, drum-like sounds, and use extra caution around ridge crests and on convex rolls. 

The winds are forecasted to shift to the northwest on friday, so watch for reverse loading.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Loose Wet

An icon showing Loose Wet

Some parts of the region will see clear skies on Friday, and may see above freezing temperatures into the alpine again. Be cautious around steep slopes that are in the sun, unless you are sure the snow surface is a thick, frozen crust.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 11th, 2022 4:00PM