Avalanche Forecast

Issued: Feb 15th, 2021 8:00AM

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

Chris Gooliaff,

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Continued faceting of surface snow and reverse-loading by N'ly winds has kept the danger rating elevated in the Alpine.

Summary

Weather Forecast

Continuing cool weather with isolated flurries the next couple of days.

Today: Cloudy with sunny periods, Alp high -10*C, light ridge winds

Tues: Cloudy with sun and isolated flurries, trace amounts, Alp high -11*C, mod W winds

Wed: Cloudy with sun and isolated flurries, trace amounts, Alp high -15*C, mod W winds

Snowpack Summary

The cold has weakened cornices and the upper snowpack. Widespread wind effect in the alpine has made for variable travel. The January 24th weak interface down 70-100 is reducing in strength with facetting due to the cold. The mid and lower snowpack are still relatively strong having rounded under previous mild temperatures and snow load.

Avalanche Summary

Numerous skier triggered and natural windslabs were observed from both lee and crossloaded features over the last few days to sz 2.5.

A group of skiers had a close call Wed on the S face of Corbin Peak, triggering a couple of large avalanches on the Jan 24th persistent weak layer. This problem hasn't gone away and still lurks on big alpine faces.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Variable mod-strong winds have changed the usual wind-loading pattern across various drainages. Look for signs of the recent local wind direction. Features can be crossloaded where terrain is bowled or gullied containing multiple aspects.

  • Watch for reverse loading created by N-NE winds.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Persistent Slabs

An icon showing Persistent Slabs

The January 24th weak interface may be triggerable on solar aspects, where facets and/or surface hoar is sitting on a suncrust.

The bond at this interface may be weakening with facets having grown under recent cold temperatures.

  • Dig down to find and test weak layers before committing to a line.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 3

Valid until: Feb 16th, 2021 8:00AM