Avalanche Forecast

Issued: Mar 9th, 2013 4:13PM

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

conrad janzen, Parks Canada

Waterton Lakes.

Spring conditions today with good skiing on N aspects! Caution for loose wet slides on solar aspects and increased cornice failures with daytime warming! Hazard will increase with warming temperatures and decrease as things cool off.

Summary

Weather Forecast

A sunny day is forecast for Sunday with thin cloud later in the day, moderate W winds, mild temperatures and freezing levels up to 1800m. For Monday and Tuesday things are uncertain. If the system stays on track we may see up to 25mm of precipitation, but if it gets pushed S things will be cloudy, fairly dry, moderate W winds and mild temperatures

Snowpack Summary

Surface hoar forming overnight. Moist snow on all solar aspects with freezing levels up to 1900m. Light wind transport at ridge crests in the alpine. The recent storm snow appears to be bonding well to the March 3 rain crust and other surfaces. This March 3 crust is present up to 2000m and is buried 10 to 45cm depending on aspect and elevation.

Avalanche Summary

A size 3 natural cornice triggered avalanche occurred near Wall Lake in the last 24hrs out of steep rocky North facing terrain and stepped down to some deeper layers in the snowpack. Today numerous loose wet avalanches on steep solar aspects up to size 2 were observed at all elevations.

Confidence

Track of incoming weather systems is uncertain on Monday

Problems

Loose Wet

Expect loose wet avalanches to occur with daytime heating. Caution on or below any steep solar aspects as temperatures warm up during the day.

Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. Travel early before the heat of the day, and avoid big slopes in the afternoon.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Cornices

With the recent snow, increasing winds and mild temperatures cornice failures are a greater concern right now. Avoid exposure to cornice threatened slopes especially with warm daytime temperatures.

Extra caution needed around cornices with current conditions.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

With increasing W winds over the next few days we can expect more wind slabs near ridge crests and in open areas above tree line. Use caution when entering wind affected areas and evaluate the snowpack carefully before committing to steep terrain.

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

Valid until: Mar 12th, 2013 5:00PM