Avalanche Forecast

Issued: Apr 5th, 2017 4:00PM

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

jonas hoke, Parks Canada

Waterton Lakes.

Be aware of what is above you, and minimize exposure to avalanche terrain during periods of rainfall.

Summary

Weather Forecast

Thursday: Cloudy, PM flurries. Ridge wind strong SW. Alpine temps, Low 1, High 3. Freezing level 2500m.Friday: Cloudy, snow/rain starts mid-day (10-20cm). Ridge wind mod-strong SW. Alpine temps, Low -3, High 1. Freezing level 2300m.Saturday: Cloudy, PM flurries. Ridge wind mod-light SW. Alpine temps, Low -8, High -1. Freezing level 2100m.

Snowpack Summary

Moderate to strong SW winds are building isolated pockets of wind slab. Incoming snow Friday will not likely bond well to previous crusty surfaces, as the snow transitions to rain expect the upper snowpack to lose cohesion quickly. The midpack is well settled and strong. Basal facets persist in some areas, but have been unreactive since mid-March.

Avalanche Summary

Numerous natural loose wet avalanches were observed on solar aspects Tuesday. Ski cutting on Tuesday also produced loose dry avalanches on North aspects at Treeline.

Confidence

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

Problems

Wind Slabs

Expect fresh slab development with snow and wind forecast for Friday.

Use caution in lee areas. Recent wind loading has created fresh slabs.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Loose Wet

New snow over old crusty surfaces will likely produce small natural avalanches with daytime warming or when rainfall commences.

Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely

Expected Size

1 - 2

Cornices

Cornices are large and continue to build with warm temps and wind. Incoming rain on Friday may be the trigger that causes cornices to fail. These will have plenty of new snow to entrain and may trigger wind slabs. Be aware of what is above you.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Dry

Dry snow persists on north aspects at upper elevations, watch for loose dry avalanches in steep north facing terrain.

Avoid terrain traps, such as gullies, where the consequences of a small avalanche could be serious.Be cautious of sluffing in steep terrain.

Aspects: North, North East, East.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1

Valid until: Apr 8th, 2017 4:00PM