Avalanche Forecast

Issued: Feb 14th, 2023 4:00PM

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

Avalanche Canada jminifie, Avalanche Canada

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The best way to manage a complex snowpack like the one in this region is to stick to smaller, low consequence terrain. Don't let your guard down as large persistent and deep persistent slab avalanches are still being reported every two or three days.

Summary

Confidence

Moderate

Avalanche Summary

A number of new natural wind slab and storm slab avalanches up to size 2 were reported from the Purcells in the last 48hrs.

Also of note from last weekend.

  • On Saturday, skiers at Quartz Creek remotely-triggered a size 3 avalanche on a northwest-facing alpine slope at 2300 m. It failed on a 40 to 80 cm deep weak layer.

  • On Friday, skiers near Invermere remotely-triggered a size 2 on a north aspect at 2400 m. The avalanche started on a 30 cm deep surface hoar layer and stepped down to the deep persistent weak layer.

Snowpack Summary

15-40 cm of of recent storm snow has been variably distributed by winds and is settling above a layer of surface hoar, facets, and/or crust. This layer has become reactive in the southern and western parts of the Purcells, where it is more deeply buried.

The lower snowpack contains a widespread layer of large, weak facets that is typically 80 to 150 cm deep. Snowpack depths at treeline range between 80 and 200 cm, with the shallowest depths found on the eastern edge of the Purcells.

Weather Summary

Tuesday night

Mostly clear. Winds from the west and southwest 10 km/h. Temperature -12˚C in the alpine.

Wednesday

A mix of sun and clouds. No precipitation. Winds from the southwest 20 km/h. Temperature -12˚C to -5˚C.

Thursday

A mix of sun and clouds. Possible flurries in the afternoon. Winds from the southwest 10 km/h. Temperature -14˚C in the morning rising to -7˚C in the afternoon.

Friday

Cloudy. Flurries delivering up to 7 cm of new snow. Winds from the southwest 10 km/h. Temperature -8˚C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Use careful route-finding and stick to moderate slope angles with low consequences.
  • Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
  • Avoid steep convex slopes.
  • Be especially cautious as you transition into wind affected terrain.

Problems

Persistent Slabs

An icon showing Persistent Slabs

Large avalanches have been triggered on a 40 to 80 cm deep layer of surface hoar and facets that was buried in late January. This problem seems most concerning in the western and southern Purcells, where the layer is more deeply buried and primed for human triggering. Steep open slopes should be avoided.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 2.5

Wind Slabs

An icon showing Wind Slabs

Wind slab avalanches are possible to trigger in lee terrain after recent snow has been redistributed by southwest wind. The bond of this snow to underlying layers is suspect.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

It remains possible for riders to trigger a weak layer of facets near the base of the snowpack. The most likely area to trigger it is in shallow areas with variable snow depths. Avoid thin and rocky start zones and select routes that avoid travelling through or under large avalanche paths.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2.5 - 4

Valid until: Feb 15th, 2023 4:00PM