Avalanche Forecast

Issued: Mar 14th, 2017 3:00PM

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

michael.olsthoorn, Alberta Parks

Kananaskis.

Avoid overhead exposure. Strong solar radiation and warming a real concern for avalanches to release into the deeper basal weak layer.

Summary

Confidence

Weather Forecast

Wednesday will bring 6cm of snow and an alpine temperature of -1c. Ridge winds are forecast for 30-40km/h from the SW. Freezing level could reach 2200m and higher on solar aspects. Overnight low temperatures of -1c are expected.

Avalanche Summary

No new avalanches were observed in our region but the visibility was poor. Our neighbours in Banff Park have reported a large avalanche cycle going into the weak basal layer. The forecasters suspect that we will see some large avalanches with the warming and strong solar radiation.

Snowpack Summary

Up to 4 cm of snow in the past 24hrs. Wind slabs are present at tree line and above on all aspects and are primed for human triggering. A large recent avalanche cycle in Banff National Park with avalanches going to the deeper layers have the forecasters concerned with the warming temperatures and strong solar radiation. The deeper layer of concern is the bottom 90cm of the snowpack which is comprised of depth hoar and facets.

Problems

Wind Slabs

Wind slabs are widespread in Alpine and Treeline terrain on all aspects, but expect deeper slabs on lee and cross-loaded features.

Avoid freshly wind loaded features.Caution in lee and cross-loaded terrain near ridge crests.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

2 - 3

Deep Persistent Slabs

Any avalanche initiated in the upper snowpack could step down to the weak basal layers resulting in a very large avalanche.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 4

Cornices

Cornice collapses are triggering slabs up to size 3.5 on underlying slopes waking up the basal layers.

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine.

Likelihood

Likely

Expected Size

2 - 4

Valid until: Mar 15th, 2017 2:00PM