Avalanche Forecast

Issued: Jan 29th, 2016 4:00PM

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

jonas hoke, Parks Canada

Waterton Lakes.

Last weeks Chinooks decimated the snowpack in much of our forecast area. The new snow is being accompanied by strong westerly winds, but should provide for some good skiing in sheltered areas near the divide.

Summary

Weather Forecast

A couple of weak fronts (warm followed by cold) will bring snowfall of up to 10cm Friday night into Saturday morning accompanied by cooling temperatures. Unsettled conditions will persist through the weekend in the wake of these fronts, with cloudy skies, cool temps, variable light to moderate winds and scattered flurries through Monday.

Snowpack Summary

Up to 12mm of precip fell Thursday, accompanied by freezing levels dropping from 2200m to valley bottom and strong westerly winds. This over firm surfaces previously affected by Strong to Extreme Chinook winds and warm temperatures. Two PWLs linger as a concern; a layer of crust or surface hoar down 40-70cm, and a crust facet layer down 70-120cm.

Avalanche Summary

Several loose wet avalanches up to size 1.5 were observed on Thursday below 2200m. An isolated size 2.0 natural slab avalanche (likely a fresh windslab) was observed Friday morning from a steep Easterly alpine slope. Neighboring ski operations have reported isolated large deep persistent slab avalanches failing on the Dec. 9th crust recently.

Confidence

Problems

Wind Slabs

Be cautious as you transition into wind affected terrain.Sheltered slopes at lower elevations will offer the best skiing.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

If triggered the wind slabs may step down to deeper layers resulting in large avalanches.Carefully evaluate terrain features by digging and testing on adjacent, safe slopes.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

1 - 3

Deep Persistent Slabs

Carefully evaluate big terrain features by digging and testing on adjacent, safe slopes.If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 3

Valid until: Feb 1st, 2016 4:00PM