Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain for the entire period
Weather Forecast
Friday: Light to moderate S/SW winds. Treeline temp -10. Occasional flurries. Freezing Level: Valley bottom.Saturday: Light to moderate S/SE winds. Treeline temp -12. Occasional flurries increasing to light snow around sunset. Freezing Level: Valley bottom.Sunday: Light west winds. Treeline temp -8. No snow. Freezing Level: Valley bottom.
Avalanche Summary
Avalanche observations from Wednesday were limited to isolated sluffing from north facing alpine terrain in the Southern Purcells.
Snowpack Summary
The recent storm deposited 15-20 cms in the North of the region near Golden, and 20-50 cms further South near the Purcell Wilderness Conservancy. Moderate to strong winds Wednesday/Thursday created windslabs 20 - 60 cm in depth at and above treeline. Windslab distribution and size is wildly inconsistent across the region, but it feels like they grow in size as you travel further south. There is some talk about a December 16th surface hoar layer, but it's distribution is *very* spotty.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.