Avalanche Forecast

Issued: Jan 20th, 2016 8:37AM

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

Avalanche Canada pgoddard, Avalanche Canada

Touchy persistent slab + new snow + rising temps + strong winds = a good recipe for avalanches

Summary

Confidence

Moderate - Intensity of incoming weather systems is uncertain

Weather Forecast

A Pacific front embedded in a southerly flow brings snow (10-40 cm total), strong S to SW winds and freezing levels rising to around 1600 m on Thursday and Friday. Precipitation and winds ease and temperatures drop on Saturday.For more details check out http://www.avalanche.ca/weather.

Avalanche Summary

Numerous large (size 2-3) persistent slabs failed naturally or with human triggers on Tuesday. Many of these were remotely triggered, highlighting the extreme sensitivity of the buried weak layer. This activity has been creeping up in size and frequency over the last few days and now seems fairly widespread, apart from in isolated parts of the region where there is insufficient snow or cohesion for a slab.

Snowpack Summary

20-50 cm of recent storm snow has formed a reactive slab over a volatile layer of buried surface hoar in many places. The buried surface hoar may be most prevalent at and below treeline. At higher elevations, this interface may exist as a crust/facet combo, which is also highly reactive. Incoming snow, with warming and strong winds, will increase the size and likelihood of the persistent slab problem, as well as adding new storm slab problems. The mid and lower snowpack are generally strong with any weak layers considered dormant for now. Snowpack depths are variable and shallow snowpack areas may have weak facetted crystals near the ground.

Problems

Persistent Slabs

An icon showing Persistent Slabs
A volatile persistent slab has been failing with light triggers.
Use conservative route selection and be aware of the potential for remote triggering. >Extra caution required in open terrain features at and below treeline.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Storm Slabs

An icon showing Storm Slabs
New snow, rising temps and strong southerly winds are expected to create a storm slab problem. Storm slabs/ wind slabs may pick up a surprising amount of mass due to the existence of a persistent weak layer.
Travel on ridgetops to avoid wind slabs on slopes below.>Avoid lee and cross-loaded terrain near ridge crests.>

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 5

Valid until: Jan 21st, 2016 2:00PM

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