Avalanche Forecast

Issued: Mar 15th, 2017 3:14PM

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

Alberta Parks jeremy.mackenzie, Alberta Parks

Avoid all avalanche terrain. A widespread avalanche cycle is on-going.

Summary

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

Another 5cm of snow is expected tonight before Thursday brings a cloudy day with sunny periods and isolated flurries. Alpine temperatures will reach a high of -8 °C with the freezing level at 1400m. Winds will be out of the west at 40-55 km/h. A storm is approaching on Friday and Saturday possibly bringing significant snowfalls, warm temperatures and strong winds.

Avalanche Summary

A widespread natural avalanche cycle up to size 3.0 is occurring on all aspects at all elevations with many slides reaching the end of their run-outs. Many avalanches are stepping down to the basal weak layers with fractures as deep as 2 metres.

Snowpack Summary

10 to 15cm of new snow above 2300m and rain below this elevation. The snowpack is settling rapidly. A widespread natural avalanche cycle is on-going (see Avalanche Activity Discussion). The mid-pack remains dense and the basal layers remain weak. Up to 100cm of depth hoar and facets make up the base of the snowpack.

Problems

Wind Slabs

An icon showing Wind Slabs
Wind slabs are widespread in Alpine and Treeline terrain on all aspects, but expect deeper slabs on lee and cross-loaded features. Wet slabs at lower elevations are occurring due to the recent rain.
Caution in lee and cross-loaded terrain near ridge crests.Avoid freshly wind loaded features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

2 - 3

Deep Persistent Slabs

An icon showing Deep Persistent Slabs
Any avalanche initiated in the upper snowpack could step down to the weak basal layers resulting in a very large avalanche. Recent wet snow has overloaded this layer resulting in large avalanches.
Be aware of the potential for wide propagations.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 4

Cornices

An icon showing Cornices
Cornice collapses are triggering slabs up to size 3.5 on underlying slopes waking up the basal layers.
Extra caution needed around cornices with current conditions.Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

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

Elevations: Alpine.

Likelihood

Very Likely

Expected Size

2 - 4

Valid until: Mar 16th, 2017 2:00PM