Parks Canada conrad janzen, Parks Canada

Waterton Lakes National Park Avalanche Forecast

Dec 20th, 2012 4:00PM

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

Good skiing in sheltered locations.  Watch for early season hazards like rocks and stumps at lower elevations.  Pay close attention to localized wind effect.

Summary

Weather Forecast

A cold front will bring moderate precip until it clears the area on Friday afternoon. The arctic high over the prairies will cause an overall drop in temperatures to near -25'C by mid-weekend, but this should trap moist air against the divide and allow for light accumulations through Sunday.  Moderate SW will continue through the forecast period.

Snowpack Summary

Windslabs at ridge crests and in the alpine with recent SW winds.  25-30cm of storm snow bonding well to previous surfaces.  The Nov 29/Dec 3 crust down 60 to 70cm is producing broken shears in facets below the crust.  This crust disappears above 2000m.  Snowpack depth at treeline is 170cm but varies widely due to previous strong winds

Avalanche Summary

No new avalanches observed over the past several days.

Confidence

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

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible - Unlikely

Expected Size

1 - 2
Wind slabs forming near ridge crests and open areas due to strong SW winds over the last couple of days.  Use your poles and skis to probe/feel for wind slabs. 
Be careful with wind loaded pockets while approaching and climbing ice routes.Caution in lee and cross-loaded terrain near ridge crests.

Aspects:

North, North East, East, South East.

Elevations:

Alpine, Treeline.

Valid until: Dec 23rd, 2012 4:00PM