Avalanche Forecast

Issued: Mar 2nd, 2023 4:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Deep Persistent Slabs.

Avalanche Canada ahanna, Avalanche Canada

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Friday will be a game of convective precipitation roulette. If it's snowing hard in your local area, treat avalanche danger as HIGH. Regardless of the weather, storm slabs are already deep and will remain reactive. Stick to conservative terrain and avoid overhead hazard.

Summary

Confidence

Moderate

Avalanche Summary

Preliminary observations from the storm include natural size 2-3 south of the Skeena as well as natural and skier triggered loose dry out of steep terrain. Explosive work near Stewart produced up to size 2.5.

Prior to this storm, storm and wind slabs were reactive. In the past few days, we've had reports of naturals size 2-3 and skier triggered storm slabs up to size 2, some remotely triggered from a distance.

Snowpack Summary

40-60 cm of new snow has been loaded into leeward terrain features at wind-exposed elevations, while remaining soft and fluffy in sheltered areas.

A layer of small surface hoar or facets is now buried over 80 cm deep. A facet/crust layer formed in late January exists around 150 cm deep. Large avalanches were suspected to have run on this layer over a week ago.

The lower snowpack is generally well consolidated but as you move further inland where the snowpack is thinner, basal instabilities linger.

The total height of snow in the alpine varies between 450 cm near the coast and 250 cm further inland.

Weather Summary

A cool, unstable airmass produces convective precipitation over the region. This means localized snowfall amounts that can vary widely. This airmass is forecast to migrate south of the region by the end of Friday.

Thursday night

5-20 cm of new snow. Strong southwest wind. Alpine low -10 ºC.

Friday

1-10 cm of new snow. Light to moderate southwest wind. Alpine high -8 ºC.

Saturday

Mostly sunny. Moderate to strong easterly wind. Alpine high -8 ºC.

Sunday

Mostly sunny. Light to moderate easterly wind. Alpine high -12 ºC.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Be careful to keep storm day fever from luring you out into bigger terrain features.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Be aware of the potential for large, destructive avalanches due to the presence of deeply buried weak layers.

Problems

Storm Slabs

An icon showing Storm Slabs

Fresh storm slabs will likely remain reactive. The deepest and touchiest deposits are likely to be found in lee terrain features at wind affected elevations.

Low density snow that hasn't formed a slab will be prone to loose dry sluffing in steep terrain at all elevations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A variety of buried weak layers have been stressed by the sudden hit of new snow load. Very large, destructive avalanches are possible.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2.5 - 4

Valid until: Mar 3rd, 2023 4:00PM