Avalanche Forecast

Issued: Jan 17th, 2016 4:00PM

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

Ruari Macfarlane, Parks Canada

Waterton Lakes.

The good skiing is currently in sheltered trees. This terrain is also less likely to have Wind Slab sitting on the widespread early January weak layer - a no-brainer! Avoid areas where the snow feels grabby, stiff, or slab- like.

Summary

Weather Forecast

Temperatures rose sharply Saturday night, but should cool slightly to hover around -5 at Treeline the next few days. Expect variable cloudiness, with occasional light snowfall, but nothing significant until Tuesday night, when we could see 5-10cm of new snow. Winds Strong from the SW on Sunday night and Tuesday night, otherwise Moderate.

Snowpack Summary

25cm of recent snowfall has made for good skiing below treeline, and sluffing in steep terrain. Strong SW winds are blowing this around to form Wind slabs in lee areas, and warm temperatures may be turning unconsolidated recent snow into storm slabs. These sit on a weak layer of Facets and Surface Hoar, or sun crust, down 25-50cm.

Avalanche Summary

Several Size 1 Loose Dry avalanches were artificially triggered by parks forecasters in steep trees near Cameron Lake on Friday, and numerous natural Size 1 Loose Dry avalanches were observed today from steep terrain at all elevations. One natural Size 1.5 Wind Slab was observed today in alpine terrain, triggered by sluffing from cliffs above.

Confidence

Due to the number of field observations

Problems

Wind Slabs

These may lie on a weak layer formed in dry weather during early January - suncrust on solar aspects, and facets / surface hoar all other aspects. Dig to see if this layer exists before committing to open slopes, as it may allow wide propagations.

Assess start zones carefully and use safe travel techniques.Use caution in lee areas. Recent wind loading has created wind slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Dry

Soft surface snow will readily sluff from any steep terrain not already scoured by wind. Wind gusts or skier traffic may trigger these.

The volume of sluffing could knock you over; choose your climb carefully and belay when exposed.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 1

Valid until: Jan 20th, 2016 4:00PM