Avalanche Forecast

Issued: Jan 28th, 2016 8:14AM

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

ccampbell, Avalanche Canada

Purcells.

Continued conservative decision making is recommended as the snowpack settles and adjusts to the recent load and warming.

Summary

Confidence

High

Weather Forecast

FRIDAY: A mix on sun and cloud with isolated light flurries possible. Freezing levels dropping to 1200m and light southwesterly winds. SATURDAY: A mix of sun and cloud but mainly dry. Freezing levels dropping to 1000m and light northwesterly winds. SUNDAY: A mix of sun and cloud and mainly dry with freezing levels dropping below valley bottoms and light northwesterly winds.

Avalanche Summary

Reports from Wednesday include several natural wind slab avalanches up to Size 2 predominately on north through east aspects and on cross-loaded features in steep aline terrain. On Thursday, explosives control produced relatively harmless loose wet and storm slab avalanches as well as 30-50cm deep persistent slab avalanches up to Size 1.5 running on surface hoar buried early January.

Snowpack Summary

Most areas are reporting 10-25 cm deep fresh wind slabs that were loaded from moderate to strong southwest winds. Weakness linger within and under the 30-60cm of recent storm snow with reports of moderate sudden results in snowpack tests. The persistent weak layer of surface hoar buried early-January is now typically down 40-70 cm and appears to be quite touchy in some parts of the region. In general, the lower snowpack is well settled and strong.

Problems

Wind Slabs

Fresh wind slabs lurking below ridge crests and behind terrain features are sensitive to human triggers. Cornices are also large and fragile.

Avoid freshly wind loaded features. >Use ridges or ribs to avoid pockets of wind loaded snow. >Be cautious as you transition into wind affected terrain. >

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Surface hoar buried at the beginning on January remains a concern for human triggers. The potential for widespread propagation and remote triggering makes this persistent slab particularly tricky to manage.

Avoid open slopes and convex rolls at and below treeline, and north-facing alpine slopes, where buried surface hoar may be preserved. >Be aware of the potential for remote triggers and wide propagations due to a layer of buried surface hoar. >

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 5

Valid until: Jan 29th, 2016 2:00PM