Avalanche Forecast

Issued: Dec 20th, 2015 4:00PM

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

jonas hoke, Parks Canada

Waterton Lakes.

The skiing may have been ruined by the wind to some degree today. Hopefully it will recover on Monday night.

Summary

Weather Forecast

A weak upper front passing the region tonight will bring light snowfall (up to 5cm) and continued strong SW wind. Some models are forecasting a brief upslope flow Monday evening, with the most optimistic predicting 15 cm of snow - this accompanied by light winds from the NE. Conditions remain cool and unsettled through Wed, with the odd flurry.

Snowpack Summary

10-15cm of dense new snow is being redistributed into wind slabs by strong (gusting extreme) SW winds. A rain crust from Dec. 9th is buried 40-55cm down at tree line and below, and a widespread mid-November crust (buried down at least 60cm) is sandwiched within a strong lower snowpack.

Avalanche Summary

No new avalanche activity. A size 1.5 avalanche was observed out of the extreme terrain on the East face of Forum peak yesterday.

Confidence

Timing, track, or intensity of incoming weather system is uncertain

Problems

Wind Slabs

These may be hidden under light new snow by Tuesday.

Use caution in lee areas. Recent wind loading have created wind slabs.Avoid freshly wind loaded features.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Storm Slabs

May be building Monday night.

The new snow will require several days to settle and stabilize.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Dec 23rd, 2015 4:00PM