Avalanche Forecast

Issued: Apr 7th, 2018 3:00PM

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

jeremy.mackenzie, Alberta Parks

Kananaskis.

Spring weather conditions are slowly starting to transform the snowpack. Avalanche danger will rise rapidly during periods of intense solar radiation and rising freezing levels.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

The region could see 5cm of new snow overnight, with Sunday bringing a mix of sun and cloud and isolated flurries. Temperatures are a bit milder than we have had recently with highs in the Alpine of -4 Â°C and the freezing level near 2200m. Winds will be moderate from the west. Conditions will remain unsettled into the early part of the week.

Avalanche Summary

A few loose wet avalanches up to size 1.5 occurred this afternoon on steep solar aspects.

Snowpack Summary

Warm temperatures and mostly sunny skies on Saturday led to moist snow on solar aspects at all elevations and at lower elevations on polar aspects. Wind slabs in the Alpine are highly variable in distribution and density, but are most commonly found near ridgelines in lee and cross-loaded terrain. On steep solar aspects in the Alpine there is a 30 to 50cm thick slab overlying the March 15th crust, and though this condition is not widespread there has been some avalanche activity associated to this problem recently. Cornices are large, are feeling the heat of the April sun, and should be avoided.

Problems

Wind Slabs

Wind slabs are being encountered along ridgelines in alpine terrain. Watch for surface and near-surface slabs in lee and cross-loaded features. Incoming snow, wind and warm temps will add to this problem.

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.

Likelihood

Possible

Expected Size

1 - 2

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

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

Expected Size

1 - 2.5

Valid until: Apr 8th, 2018 2:00PM