Avalanche Forecast

Issued: Jan 29th, 2018 4:08PM

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

max darrah, Parks Canada

Jasper.

Rapid loading on top of persistent weak layers is expected to create dangerous avalanche conditions over the next few days.Closures of HW 93 (Icefield Parkway) will be in effect starting Jan 29 for control work. 511.Alberta.ca for updated info.

Summary

Weather Forecast

Heavy snowfall Monday night, with amounts between 20-40cm possible for the Columbia Icefields area. Moderate SW winds to accompany this snowfall. Pressure rising mid-week as precipitation tapers. Temperatures will drop later in the week as an Arctic ridge establishes itself along the Eastern slopes of the Rockies.

Snowpack Summary

Incoming new snow is building fresh storm slabs and is falling on a persistent slab made up of 3 weak interfaces in the top 30 to 50cm of the snowpack. Depth and distribution of these weak surface hoar/facet layers varies within the terrain; although buried surface hoar has consistently been found in sheltered features at TL.

Avalanche Summary

Avalanche control on Parkers Ridge Friday produced 2 large avalanches, size 2 and 3 on a NE aspect running as a persistent slab. Numerous sloughs observed today from steep rocky terrain.

Confidence

Forecast snowfall amounts are uncertain

Problems

Storm Slabs

Incoming new snow and wind will build fresh storm slabs.

Minimize overhead exposure during periods of heavy loading from new snow, wind.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

This problem is made up of 3 significant interfaces in the upper snowpack. Incoming new snow may overload these layers, which have recently been reactive to skier testing and explosive control work, producing a few very significant results.

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.Be aware of the potential for large, deep avalanches due to the presence of buried surface hoar.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

Watch for sluffing in steep terrain.

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 1.5

Valid until: Jan 30th, 2018 4:00PM