Avalanche Forecast

Issued: Mar 29th, 2013 4:00PM

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

tim haggarty, Parks Canada

Waterton Lakes.

Fairly difficult skiing conditions right now will make longer tours with mild descents more appealing. Plan your trips to take advantage of the overnight freezing to allow for fast travel and be cautious on slopes where the slope is moist or wet.

Summary

Weather Forecast

Saturday: Convective clouds with moderate west winds, freezing level 2200m Sunday: Increased cloud cover with the potential for some light precip as a cold front pushes in from the Prairies. Winds shifting N and temperatures cooler with invading polar air. Freezing level 1900m Monday: Clear skies and warmer temperatures freezing level 2400m

Snowpack Summary

A trace of new snow fell above 1900m last night. This will overly Sun Crust on steep East through West aspects and Temperature or Rain Crusts as high as 2200m on all aspects. Winds have created thin windslabs over these crusts in open areas Treeline and above.

Avalanche Summary

We are into a predictable pattern of daily heating that produces wet loose avalanches especially as the sun exerts it's effect on Solar Slopes. Several Cornice failures have been observed as a result of this heating as well and these should remain a concern for skiers seeking dry snow on NW to E aspects.

Confidence

Timing or intensity of solar radiation is uncertain

Problems

Loose Wet

As the daytime temperatures rise we may see loose wet avalanches on steep solar aspects especially if dark objects like rocks and trees are present on the slopes. Travel early on steep solar aspects and pay close attention to daytime temperatures.

Make your travel plans to take advantage of overnight freezing.Minimize exposure to sun exposed slopes when the solar radiation is strong.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Cornices

With warm temperatures and clear skies in the forecast, expect continued cornice failures. These are large triggers and have the potential to create larger avalanches. Minimize your exposure especially during rapid warming as the sun comes out.

Give cornices a wide berth when travelling on or below ridges.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

Wind slabs have developed in most open areas tree line and above. In most places these wind slabs are bonding well to the surfaces below but assess this bond carefully before entering steep or committing terrain.

Make observations and assess conditions continually as you travel.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Apr 1st, 2013 4:00PM