Avalanche Forecast

Issued: Jan 3rd, 2019 4:00PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is considerable. Known problems include 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

10-15 cm of recent 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 the weekend. The Surface Snow is moist to 1550m.

Avalanche Summary

Lim observations today due to Extreme Wind event.

Confidence

Due to the number of field observations on Thursday

Problems

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

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Jan 6th, 2019 4:00PM