Avalanche Forecast

Issued: Jan 21st, 2018 3:55PM

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

Avalanche Canada jlammers, Avalanche Canada

In the south and western parts of the region, heavy snowfall is expected to continue and keep the avalanche danger at HIGH.

Summary

Confidence

Moderate - Due to the number of field observations

Weather Forecast

Monday: 5-10cm of new snow / Moderate westerly winds / Freezing level at 700mTuesday: 8-15cm of new snow / Moderate southerly winds / Freezing level at 400mWednesday: 7-15cm of new snow / Moderate southerly winds / Freezing level at 1000m

Avalanche Summary

An impressive natural storm slab avalanche cycle is expected to have occurred in response to new snow and wind on Monday. On Tuesday, natural avalanche activity is expected to continue, particularly in direct coastal areas where heavy snowfall is forecast to persist.

Snowpack Summary

The region has been pummeled by heavy snowfall and extreme southerly winds. By Monday morning expect about a metre of snow to have fallen in the past 48 hours. Thanks to the winds, I would anticipate extensive scouring and redistribution of the recent storm snow at all elevation bands with dense storm slabs lurking in lee and cross-loaded features. Impressive cornice growth is also expected to have occurred.About 150cm below the surface you'll find a crust that was buried mid-January and is present at all elevations. This crust is thin on northerly aspects and up to 3 cm thick on solar aspects. Most reports suggest an improving bond at this interface, but the load of the new snow may tip the balance and reactivate this layer in isolated terrain. Below this, the snowpack is generally strong and well-settled.

Problems

Storm Slabs

An icon showing Storm Slabs
An impressive storm has just occurred, and deep and dense storm slabs lurk in lee and cross-loaded terrain. This isn't the sort of avalanche problem you manage with a ski cut. Only time will help the snowpack adjust to the weight of the new snow.
The new snow will take time to settle and stabilize.Be aware of the potential for wide propagations due to the presence of hard windslabs.Be cautious as you transition into wind affected terrain.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Valid until: Jan 22nd, 2018 2:00PM