Avalanche Forecast

Issued: Mar 1st, 2016 7:14AM

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

mike.koppang, Alberta Parks

Kananaskis.

Windslabs will very likely be quite touchy for the next few days. These slabs are sitting over a variety of crusts buried in the upper snowpack at treeline. We are expecting natural avalanche activity and a high likelihood for human triggered slides.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

A low pressure system will be moving through the Rockies tonight bringing light snowfall amounts (up to 10cm) and strong southwesterly winds.Â Tomorrow will see partly cloudy skies, the winds will be moderate out of the southwest and gusting to 60km/h.Â Temperatures in the alpine around -6.0.Â Freezing levels will rise to 1400 meters.

Avalanche Summary

A few loose dry avalanches released out of north facing steep, rocky & unskiable faces and flushed out in the fans to size 1.0. On Mt. Buller in the northeastern corner of our forecast region, a cornice triggered wind slab scrubbed to ground and ran almost to the full run-out, size 2.5.

Snowpack Summary

10-25cm of storm snow exists over a new melt-freeze / suncrust layer that was buried on February 27th. This new soft slab over these crusts are not reactive at the moment but with additional load and winds which are forecast for tonight, we anticipate this interface will be reactive to skier traffic. The other layers of concern are the February 11th melt-freeze / suncrust (30-50cm deep) and the January 11th facets (60-100cm deep). These crusts will be most problematic at treeline elevations, snowpack tests revealed sudden collapses below these crusts on facets so exercise caution as you work through terrain and pay particular attention to the solar aspects where the crusts are strong and intact and remember that crusts are generally never trustworthy in the presence of wind slabs. The mid pack and basal layers are strengthening and generally well settled.

Problems

Storm Slabs

The new storm slab is a soft slab which overlies the recently buried Feb 27th meltfreeze / suncrust. Tonight we are expecting 10cm of new snow and strong winds from the southwest. This crust interface will be very touchy to a skier's weight.

Be cautious of sluffing in steep terrain.>Good day to make conservative terrain choices.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Wind Slabs

As previously discussed, windslabs are going to be primary issue and we are expecting an avalanche cycle with the new snow and strong winds. These windslabs will be highly reactive, especially in the immediate lee at treeline and alpine ridges.

Avoid cross loaded slopes at or above treeline.>Avoid freshly wind loaded features.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Persistent Slabs

Forecasters today investigated the Jan 6th Facet layer and in a deep tap test, a sudden collapse result was found. This layer although showing signs of deteriorating and becoming dormant, it is still responsible for the odd large (size 3) avalanche.

Be aware of the potential for large, deep avalanches.>Pay attention to overhead hazards like cornices.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely

Expected Size

2 - 5

Valid until: Mar 2nd, 2016 2:00PM