Avalanche Forecast

Issued: Jan 4th, 2019 4:00PM

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

Marcus Waring, Parks Canada

Waterton Lakes.

There has been significant Wind Slab development with the recent extreme wind event. Expect these new Wind Slabs to become more reactive with the rising freezing level on Saturday.

Summary

Weather Forecast

FRIDAY 10-15 cm of precipitation with strong SW winds and gusts up to 90km/h SATURDAY Freezing Levels rising to 1900m with winds easing to 40 km/h. Sunny.SUNDAY 5-10 cm precipitation with a 1200m freezing Level and Moderate SW winds.

Snowpack Summary

15-20cm of storm snow with Extreme SW winds has led to significant Wind Slab development in lee terrain. Expect these wind Slabs to become more reactive as the freezing level rises to 1900m on Saturday. The mid snowpack is generally well settled but there is potential for avalanches to step down to deeper weak layers.Surface Snow is moist to 1550m.

Avalanche Summary

Limited visibility during this storm cycle.

Confidence

Freezing levels are uncertain on Saturday

Problems

Storm Slabs

If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Use caution in lee areas. Wind loading could create slabs.

Aspects: North, North East, East, West, North West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Persistent Slabs

Avoid convexities and thin snowpack locations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Jan 7th, 2019 4:00PM