Avalanche Forecast

Issued: Nov 26th, 2020 4:00PM

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

kdevine, Avalanche Canada

Cariboos.

A big storm is hitting the Cariboos with heavy snowfall and strong winds. Avoid avalanche terrain and overhead hazard.

Summary

Confidence

Moderate - We are confident the likelihood of avalanche will increase with the arrival of the forecast weather.

Weather Forecast

THURSDAY NIGHT - Snow, 15-25 cm / southwest wind, 40-60 km/h, gusting to 80 km/h / alpine low temperature near -7 / Freezing level 1000 m

FRIDAY - Snow 10-20 cm / southwest wind, 40-60 km/h, gusting to 80 km / alpine high temperature near -6 / Freezing level 1100 m

SATURDAY - A mix of sun and cloud with isolated flurries / west wind, 30-50 km/h, easing in the afternoon / alpine high temperature near -8

SUNDAY - Cloudy with sunny periods / south wind, 20-30 km/h / alpine high temperature near -6

Avalanche Summary

A natural avalanche cycle is expected for Friday with the arrival of forecast weather.

Snowpack Summary

15-25 cm of new snow on Thursday night with another 10-20 cm expected during the day will arrive with strong southwest winds. Storm slabs will likely be widespread in the region. There is a crust from early November now down approximately 75-125 cm. This crust has been observed with sugary facets above and below it. There are limited observations on this layer, but some test results indicate that it has the potential to be reactive to human triggering. Total snowpack depths are an average of 90-180 cm at upper elevations, tapering quickly at lower elevations.

Terrain and Travel

Storm slab size and sensitivity to triggering will likely increase through the day.
Avoid all avalanche terrain during periods of heavy loading from new snow and wind.
Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

25-45 cm is expected by Friday afternoon with strong southwest winds. Touchy storm slabs are anticipated to be widespread.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1.5 - 2.5

Deep Persistent Slabs

A crust from early November exists down about 75-125 cm, and may have weak sugary facets above and below it. Storm slab avalanches may step down and trigger this layer, resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 27th, 2020 4:00PM