Avalanche Forecast

Issued: Feb 18th, 2013 5:34PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Loose Dry.

tim haggarty, Parks Canada

Waterton Lakes.

New windslabs and surface sluffing are the main avalanche concerns right now. Hopefully the light winds forecast for the period will delay further slab growth. Good skiing remains in shaded areas following intense radiation today.

Summary

Weather Forecast

Tuesday- Light S-SW winds. Sunny periods in the AM with freeze level to 1700. Cloudy with Flurries afternoon.Wednesday- Light W winds. Mainly cloudy with flurries. Freeze level 1300m.Thursday-Â Light to Moderate W winds. Cooler temperatures with some clearing.

Snowpack Summary

20cm on Feb 16 interface comprised of suncrust steep solar aspects, rain crust to 1900m and windslab in open areas. New windslabs forming in exposed terrain TL and above with SW winds. New suncrusts forming today with strong solar input steep East and South slopes. Profiles today BTL showed weakening of the mid and lower snowpack with faceting.

Avalanche Summary

Widespread Loose Dry avalanches have been seen failing within the storm snow in mainly extreme terrain. Although most of these events could be called surface sluffs one notable event today ran a considerable distance and reached class 2 in size.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

New slabs forming in exposed areas with SW winds. These are spotty and small right now but will grow in size and thickness with time. Monitor the texture of the snow as you move into open areas and avoid steep terrain where these slabs are present.

Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Loose Dry

Sluffing occurs easily given terrain over 40 degrees. This will diminish as the storm snow settles and is likely to occur only on shaded slopes following the solar heating on Feb 18. Manage your sluff and your group carefully.

Be aware of party members below you that may be exposed to your sluffs.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 21st, 2013 4:00PM