Avalanche Forecast

Issued: Jan 18th, 2015 4:10PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Parks Canada will be conducting control work on Mt. Bourgeau along the Sunshine access road Monday January 19. No climbing or travel in this area. TH.

Summary

Weather Forecast

The remains of Sunday's storm should play out by early Monday morning and bring another 5 to 10 cm as temperatures start to cool. Winds should also diminish around midnight but will likely remain in the moderate range at the treeline level. Expect a light snowfall 5 to 10 cm Monday with continued cooling into Tuesday before we may see some clearing

Snowpack Summary

10 to 20cm recent snow sits on facets, surface hoar, sun crust on steep South slopes, and hard windslabs along ridge crests at Treeline and above. Wind slabs are rapidly building in many open areas above tree line. In general the snowpack is weak with well developed faceting at the Dec 18 interface and depth hoar commonly seen at the base.

Avalanche Summary

Although visibility was too poor to see any natural activity, skiers were able to easily trigger freshly formed windslabs today in any open lee features at Treeline and above.

Confidence

Intensity of incoming weather systems is uncertain on Sunday

Problems

Wind Slabs

New windslabs 10 to 40cm deep can be found in almost any lee areas including crossloaded features. These slabs will continue to build Sunday night and Monday with continued precipitation and winds.

Avoid freshly wind loaded features.Minimize overhead exposure during periods of heavy loading from new snow, wind.

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

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2

Persistent Slabs

With fresh slabs forming above this weak layer down 25 to 50cm it is possible that it becomes active. In shallower snowpack areas this layer has been facetting out. In deeper areas where a stronger slab exists above this layer it is more of a concern

Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

In shallower snowpack areas (most of the region) the weak base of the snowpack persists and could be triggered in steep, rocky terrain features. This problem will persist for some time, give it careful consideration before entering serious terrain.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 19th, 2015 4:00PM