Avalanche Forecast

Good

A light Northwesterly flow will persist through the region Saturday. A “dirty ridge” of high pressure sets up and slowly pushes through Sunday and into the outlook. Saturday: Snow amounts near 5 cm accompanied by light NW ridgetop winds. Alpine temperatures near -10 and freezing levels at valley bottom through the forecast period.Sunday: Mainly sunny with some scattered clouds. Alpine temperatures near -13 accompanied by light-moderate NW ridgetop winds.Monday: A mix of sun and cloud. Alpine temperatures near -12 accompanied by light West ridgetop winds.

Last Sunday afternoon, skiers triggered a size 3.0 slab avalanche from the ridgeline off Mt. Fernie. The initial trigger was a smaller wind slab which then stepped down to a deeply buried rain crust. There were no human involvements. For further details, please visit the Incident report here:  http://www.avalanche.ca/cac/library/incident-report-database/view.No new avalanche observations reported on Friday.

The recent storm snow seems to be settling out with no significant layers. Moderate winds from the SW-NE have built wind slabs that may be sensitive to rider triggers. Areas that may host a wind slab problem are lee slopes and behind terrain features (spines, gullies, ridgelines). Two crusts have been identified in the snowpack: one close to the ground that formed in early November down 170-200 cm and one around 90-140 cm below the surface, which formed in early December. Recent snowpack tests done on the December crust from the Harvey Pass Riding Area showed a moderate compression test failure, with a sudden collapse characteristic but inconsistent results. Testing done in the Crowsnest South Riding Area showed compression tests in the moderate range with non planar breaks. Its important to dig down and test the reactiveness of these layers in your local riding areas. This layer may be difficult to trigger, however typical trigger points are thin-thick snowpack areas, cross loaded gullies or around rocky outcrops. If triggered a large destructive avalanche may occur. The mid pack is generally well settled throughout the region.