Avalanche Forecast

Issued: Mar 22nd, 2023 4:00PM

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

Avalanche Canada isnowsell, Avalanche Canada

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While avalanche activity is generally unlikely due to a supportive melt-freeze crust, continue to use caution in areas where a weak basal facet layer exists - steep, rocky terrain with variable snow depths.

Summary

Confidence

High

Avalanche Summary

A large (size 2.5) deep persistent slab avalanche was reported yesterday in the South Chilcotin range. It was triggered naturally at roughly 2200 m on a south-facing slope.

Wet-loose avalanches up to size 1.5 have been reported daily during the recent warm, sunny weather.

If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.

Snowpack Summary

On the surface is a widespread melt-freeze crust existing on all aspects at treeline and below, along with solar aspects at all elevations. This crust is unlikely to breakdown Thursday with cooler temperatures and cloud cover forecast. The surface snow in northerly-facing alpine terrain remains generally cold and dry.

The middle of the snowpack is generally settled and bonding, with no current concerns.

At the base of the snowpack is a layer of weak, sugary facets, reportedly up to 50 cm thick.

Weather Summary

Wednesday night

Clear with cloudy periods. Treeline temperatures 0 to -5 C. Light southwest ridgetop winds. Freezing level 500 m.

Thursday

Mostly cloudy, with isolated flurries. Treeline temperatures 0 to -5 C. Light south ridgetop winds. Freezing level 1500 m.

Friday

Cloudy, with flurries. Treeline temperatures -5 to -10 C. Light south ridgetop winds. Freezing level 1300 m.

Saturday

Mix of sun and cloud. Treeline temperatures -5 to -10 C. Light south ridgetop winds. Freezing level 1200 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • A crust on the surface will help bind the snow together, but may make for tough travel conditions.
  • In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.

Problems

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A layer of weak facets sits near the base of the snowpack. This layer is most likely to be problematic in steep, wind-loaded terrain where the snowpack depth varies from thick to thin. Especially in the northern part of the region around the Chilcotins, Birkenhead, and Hurley.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 3.5

Valid until: Mar 23rd, 2023 4:00PM