Avalanche Forecast

Issued: Mar 11th, 2016 4:07PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is low. Known problems include Storm Slabs, Cornices and Loose Wet.

jonas hoke, Parks Canada

Waterton Lakes.

Winter returns at upper elevations, time to get back in the mind set of choosing terrain carefully. JH

Summary

Weather Forecast

Saturday: A cold front passes over the area giving; moderate to strong SW wind; 10-15 cm of snow, and freezing levels spiking to TL as the front approaches then dropping to valley bottom.Sunday-Monday: Unstable air in the wake of the front will give ongoing cool temps, cloudy skies and flurries. Accumulations of up to 10cm are forecast.

Snowpack Summary

Thursdays heavy snowfall and strong SW winds built storm slabs up to 40cm deep over the early March rain crust (present on all aspects into the lower alpine), these remained sensitive to human triggering Friday. The mid and lower snowpack is generally well consolidated, and is made up of a series of crusts at lower elevations and on solar aspects.

Avalanche Summary

Numerous naturally triggered small to large storm slab avalanches occurred on N-E (lee) aspects during Thursdays storm. Ski cutting in a steep lee at treeline produced a small (size 1.5) storm slab avalanche on Friday, this was observed to have run on the early March crust.

Confidence

Forecast snowfall amounts are uncertain

Problems

Storm Slabs

Snow showers through the weekend will continue to add to the load on the early March crust. With this crust as a potential weak interface these storm slabs may be slow to strengthen.

Avoid steep lee and cross-loaded slopesBe careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Expect ongoing cornice development with warm temperatures and snowfall at the start of the weekend. These may become brittle as temperatures cool.

Give cornices a wide berth when traveling on ridges.Minimize exposure to overhead hazard from cornices.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Loose Wet

Use caution above cliffs where small avalanches may have severe consequences.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1

Valid until: Mar 14th, 2016 5:00PM