Avalanche Forecast

Issued: Dec 20th, 2018 4:04PM

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

marcus waring, Parks Canada

Waterton Lakes.

Wind Slabs a brewing. 10-15 cm overnight tonight with strong SW winds gusting to 110km/h.

Summary

Weather Forecast

10mm of precipitation is expected overnight with the current high freezing levels dropping to valley bottom around midnight. Strong SW winds with gusts up to 110 km/h will continue until Saturday morning. Trace precipitation over the weekend with Moderate SW winds and average alpine temperatures around -10°c.

Snowpack Summary

Warm temperatures today. Moist surface snow to 1800m. Variable Snowpack depth 20-160cm. Tree line average snowpack 80cm. Windslabs will continue to build with the incoming storm cycle. There is potential for windslabs to step down to weak layers within the lower snowpack.

Avalanche Summary

No avalanches observed at Cameron Lakes. One Natural Size 1 Windslab observed on a West Aspect of the Akamina Parkway.

Confidence

Wind effect is extremely variable on Friday.

Problems

Wind Slabs

Use caution in lee areas. Recent wind loading have created wind slabs.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

caution shallow trigger locations

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Valid until: Dec 23rd, 2018 4:00PM