Avalanche Forecast

Issued: Apr 9th, 2018 3:24PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

The snowpack is not likely to get a good freeze overnight, so loose wet avalanches at lower elevations may be a problem in addition to those already identified in the "Avalanche Problem" section.

Summary

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Tuesday will bring light flurries with accumulations between 5 and 10cm.Â Alpine temperature will reach a high of 0 Â°C with freezing levels near 2400m or higher. Ridge-top winds will be from the southwest at 30 km/h gusting to 60 km/h. Long term forecasts have a significant snowstorm arriving on Thursday will accumulations near 25cm. Apparently it's not yet Spring!

Avalanche Summary

A few naturally triggered slabs have been observed in very steep Alpine terrain on solar aspects in the past 24 to 48hrs. These slides were up to size 2.0 and were 50cm deep on average.

Snowpack Summary

Moist snow on all aspects up to 2300m and higher on solar aspects, butÂ moderate winds kept the upper Alpine cooler. Both surface and buried wind slabs are found in wind prone areas in the Alpine and these have been building more into the Treeline with the persistent winds. The March 15th crust down 30 to 50cm on solar aspects has been active in recent days in isolated terrain (see avalanche summary). Cornices are large, are feeling the heat of the April sun, and should be avoided.

Problems

Wind Slabs

Watch for wind slabs in Alpine and Treeline terrain in wind prone areas such as cross-loaded gullies and immediately below ridge-lines. These slabs may become more sensitive to triggering as the temperatures rise during the day.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Evaluate unsupported slopes critically.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Cornices are large and looming. When the solar radiation is strong and/or the air temperature rises, cornice collapses could be a major concern.

Give cornices a wide berth when travelling on or below ridges.Pay attention to overhead hazards like cornices which could easily trigger persistent slabs.Cornices become weak with daytime heating.

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2.5

Persistent Slabs

The March 15th melt-freeze crust, buried 30-50cm on solar aspects, could be an issue on bigger slopes, particularly in the Alpine. Evaluate the snowpack for the presence/absence of this problem layer before committing to a terrain feature.

Avoid steep Southerly aspects.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Apr 10th, 2018 2:00PM