Avalanche Forecast

Issued: Apr 2nd, 2021 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

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High elevation north aspects hold the best snow but are also the most likely place to encounter wind slabs. Be ready to back off slopes as warm temperatures moisten and weaken the upper snowpack. Check out our latest blog post on managing these not-quite-yet-spring conditions.

Summary

Confidence

High -

Weather Forecast

Friday night: Partly cloudy. Light west wind. Alpine temperature -8. Freezing level valley bottom.

Saturday: Cloudy with continuing scattered flurries with up to 10 cm of new snow. Moderate to strong south winds. Alpine high temperatures around -4. Freezing levels 1600 m.

Sunday: 10-15 cm new snow overnight then clearing. Light southwest wind shifting northwest over the day. Alpine high temperatures around -5. Freezing level 1500 m.

Monday: Sunny. Light to moderate west wind. Alpine high temperatures around -2. Freezing level 1900 m.

Avalanche Summary

No new avalanches were reported in the region over the past couple of days, but reports from the neighboring North Columbias on Wednesday included small (size 1) natural and skier triggered loose wet and slab avalanches on south aspects, running on a recent crust layer. One recent natural size 2 cornice failure was also noted.

A couple of avalanche involvements were reported on Monday. We really appreciate this MIN report of a size 1.5 skier triggered storm slab on a northeast aspect around treeline. Thankfully no one was injured. 

We regret to report a fatality on Eureka Peak, east of Williams Lake on March 29. A human-triggered cornice failure resulted in a size 2.5 slab avalanche. It is important to remember to stay well back from ridgetops that might be corniced and to avoid slopes with overhead cornice exposure especially under the current conditions where recent rapid growth has made them large and fragile.

Snowpack Summary

Light accumulations of new snow have added to wind affected surfaces and cornices in alpine areas and to settled dry snow on more sheltered, shaded aspects above about 1900 metres. Below this elevation and on solar aspects it buries crusty surfaces. Crusty and/or moist surfaces exist atop the diminishing snowpack below about 1500 metres.

Recent warm weather is expected to have helped old persistent weak layers heal, including a few crusts buried over the last month as well as a facet layer 150 cm deep from the mid-February cold snap.

Terrain and Travel

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Extra caution is needed around cornices under the current conditions.
  • A moist or wet snow surface, pinwheeling and natural avalanches are all indicators of a weakening snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs

More recent wind slabs could be reactive in wind loaded terrain features at upper elevations on Friday. Light new snow in the forecast may add to this problem, forming small new slabs and obscuring recent ones.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Cornices

An icon showing Cornices

Cornices become weak with daytime warming. Cornice falls are dangerous in their own right and they can also trigger slabs on slopes below.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Apr 3rd, 2021 4:00PM