Avalanche Forecast

Issued: Nov 25th, 2020 4:00PM

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

Avalanche Canada kdevine, Avalanche Canada

Welcome to the winter 2020/2021 forecast season! Watch for reactive storm slabs at upper elevations, and be aware of the potential for larger avalanches due to a crust that was buried in early November. 

Summary

Confidence

Low - Uncertainty is due to the limited number of field observations.

Weather Forecast

 WEDNESDAY NIGHT- Mainly cloudy with scattered flurries / southwest wind, 30-40 km/h / alpine low temperature near -9

THURSDAY- Increasing cloud, snow beginning in the afternoon / southwest wind, 20-40 km/h / alpine high temperature near -7 / Freezing level 1000 m 

FRIDAY- Snow, 10-15 cm / southwest wind, 30-50 km/h / alpine high temperature near -5 / Freezing level 1000 m

SATURDAY- A mix of sun and cloud / west wind, 15-20 km/h / alpine high temperature near -8 / Freezing level 900 m 

Avalanche Summary

There have been very few reports of avalanches in the region, however observations are limited at this time. 

In the past week there have been a few size 2-3 avalanches reported on the early November crust in both the North Columbia and neighbouring Glacier National Park region.  

If you get out into the mountains, please consider sharing your observations on the Mountain Information Network!

Snowpack Summary

Up to 25 cm of recent fresh snow brings recent storm snow totals to anywhere between 20-50 cm. A crust from early November exists down approximately 80-100 cm. This crust has been observed to have weak, sugary facets above and below it. Recent tests on this layer indicate that it may be bonding poorly, and has the potential to be triggered by humans. 

Terrain and Travel

  • Avoid freshly wind loaded terrain features.
  • In times of uncertainty conservative terrain choices are our best defense.
  • If it's deep enough to ride, it's deep enough to slide (avalanche).

Problems

Storm Slabs

An icon showing Storm Slabs

Recent fresh snow has likely formed storm slabs that may be reactive to human triggering, especially in wind loaded areas.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

A crust from early November exists down about 80-100 cm. This layer has weak, sugary facets above and below it. There are limited observations on this layer right now, however some recent test results suggest that it has the potential to be triggered by humans.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Nov 26th, 2020 4:00PM