Avalanche Forecast

Issued: Mar 8th, 2021 4:00PM

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

Avalanche Canada jfloyer, Avalanche Canada

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Watch out on recently wind affected slopes and slopes experiencing direct sunshine. Buried weak layers could still be reactive, especially on slopes exposed to direct sun.

Summary

Confidence

Moderate - Uncertainty is due to how buried persistent weak layers will react with the forecast incoming weather.

Weather Forecast

MONDAY NIGHT: Clear and cold, with alpine temperatures dipping to around -11 C.

TUESDAY: Clear through most of the day, some clouds in the late afternoon. Light variable winds becoming southwesterly in the afternoon. Alpine high temperature -3 C. Freezing level 1300 m.

WEDNESDAY: Light snow, 2-5 cm. Light southwesterly winds. Alpine high temperature -5 C. Freezing level 500 m.

THURSDAY: Mostly dry with a mix of sun and cloud. Light to moderate southwesterly winds. Alpine High temperature -6C. Freezing level 700 m.

Avalanche Summary

No avalanches were reported in this region on Sunday or Monday.

A widespread avalanche cycle occurred in this region at the end of last week (around March 4-5) in response to intense wind loading and rapid warming.

Snowpack Summary

Crusty snow surfaces exist up to around 1600 m and even higher on slopes that have been exposed to direct sunshine. Cornices are present along ridgelines.

In the last week of February and the first week of March, a number of large avalanches were reported on persistent weak layers in the Cariboos. The layers of primary concern are a 50-100 cm deep layer of facets that was buried in mid-February, a 50-150 cm deep layer of surface hoar from early February that was most prevalent at treeline (and existed as a facet/crust combination on steep south-facing terrain), and finally another persistent weak layer from late January that is now roughly 100-150 cm deep. Evidence suggests these weak layers have become hard to trigger, particularly in areas to the south and east, but it's too early to write these off completely.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Minimize exposure to sun-exposed slopes when the solar radiation is strong.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Problems

Wind Slabs

An icon showing Wind Slabs

You may find pockets of wind slab behind exposed ridgelines in the alpine. Cornices may be present as well.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Uncertainty about buried weak layers warrants conservative terrain choices. There are several persistent weak layers 50-150 cm below the surface that have produced large natural and human triggered avalanches in the last week of February and first week of March. It is too soon to write these layers off and they could still be reactive, especially on south-facing slopes when the sun is out.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 9th, 2021 4:00PM