Avalanche Forecast

Issued: Jan 24th, 2016 7:48AM

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

Avalanche Canada pmarshall, Avalanche Canada

It's uncertain how much precipitation will make it inland on Tuesday/Wednesday. We could enough snow, combined with warming, to cause avalanche danger to rise again this week.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Monday: Cloudy with sunny breaks and a chance of flurries. The freezing level rises to 1000-1200 m and winds are light or moderate from the S-SW. Tuesday: Light snow 5-10 cm. The freezing level is around 1400-1600 m. Winds increase to moderate or strong from the SW. Wednesday: Cloudy with showers or flurries. The freezing level spikes to around 1600-2000 m and winds remain strong from the S-SW.

Avalanche Summary

There were no new reports of natural or human triggered avalanches on Saturday. Improved visibility on Saturday gave us a better picture of the extent of the avalanche cycle on Thursday and Friday. Most observers reported very widespread activity with numerous slab avalanches up to size 3 from all aspects and at all elevations. The common theme was that many slides showed very wide propagation, and quite a few released on surprisingly low angle slopes (25-35 degrees).

Snowpack Summary

This weeks "Pineapple Express Light" brought an average of 60-70 cm of new snow to the region. The snow line may have gone up to ridge top in the south, but only 1400-1600 m in the north. Expect dense new wind and storm slabs, and fresh cornice growth at upper elevations. Heavy loading from snow and rain, and the resulting avalanche cycle, has helped flush-out the mid- and early-January surface hoar/facet layers now down 80-120 cm deep. However, these layers are likely still intact and reactive in places and it may still be possible to trigger large slabs. The mid and lower snowpack is generally strong, with the exception of shallower snowpack areas that may be more faceted.

Problems

Persistent Slabs

An icon showing Persistent Slabs
Buried surface hoar remains primed for rider triggering, especially in the Northern part of the region where the snow line stayed below treeline during the recent storm. 
Whumpfing, shooting cracks and recent avalanches are all strong inicators of unstable snowpack.>Be wary of slopes that did not previously avalanche - even on low angle terrain.>Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Wind Slabs

An icon showing Wind Slabs
Previous strong southerly winds created deep and dense wind slabs in exposed lee and cross-loaded terrain. 
Use ridges or ribs to avoid pockets of wind loaded snow.>Choose well supported terrain without convexities.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 4

Valid until: Jan 25th, 2016 2:00PM