Avalanche Forecast

Fair - Due to variable snopack conditions

A weak system will bring a few cm's to the region Wednesday night into Thursday morning. High pressure then works its way up from the States which will keep things fairly dry Thursday afternoon into Friday. There will be broken clouds as NW flow remains aloft, the occasional flurry may even develop, but we shouldn't see any significant accumulations. Winds will ease up a bit Thursday, but they will still be strong out of the NW at ridgetop. @ 1500m expect a daytime high of -3 with an overnight low of -7 Thursday.

A couple of large natural avalanches in the alpine (to size 3) were reported on NE and SE- E aspects in the Dogtooth range Wednesday. Smaller avalanches of the loose snow & soft slab variety (to size 1.5) were also reported running in the new/old snow interface. Elsewhere in the region a natural avalanche that started in steep un-skiable terrain was observed. All the reported avalanches were running fast and entraining snow as they ran down the slope.

The Purcell’s are one of the more complex snowpacks in the province right now.Tuesday night the region received 30 – 40 cm of new snow accompanied by strong winds out of the SW. Just a few days ago the region received 20 – 40 cm with S & SE winds. A test profile on Tuesday revealed a sudden planer shear down 40 cm failing on surface hoar with a hard trigger. That was before the storm, that layer now has 70+ cm of snow on it and is likely more sensitive. Resistant shears were noted in last weekend’s storm snow yesterday too. The bottom line is that there are a number of different weaknesses/sliding layers in the snowpack which are now under additional strain.The mid-December surface hoar/facet persistent weakness, now down around 70cm on the eastern side of the range and as deep as 230cm on the western side, is still causing operators concern, especially in shallow snowpack areas. Recent snowpack tests show moderate to hard, sudden planar results on this layer. The consequences of a failure on this layer would be large. Facets and depth hoar exist at the base of the snowpack. Cornices are large and weak in some areas.