The first major avalanche cycle of the season peaked yesterday, please remember to use caution on this first blue sky day and ride safely.
Weather Forecast
Temperatures in the alpine starting at -21 rising to -14 with light to moderate ridgetop winds which are forecast to be gusty this evening. There is no snow in the forecast for the foreseeable future and temperatures are on a steady rise towards the weekend with daytime highs forecast to be -5 for Friday.
Snowpack Summary
Heavy snow fall and strong winds have rapidly loaded the snowpack. Snowpack tests yesterday found several reactive storm snow instabilities in the easy range in the top 75cm. The Nov 12 surface hoar layer, now down ~1m, gave sudden planar results on an E aspect at 1980m. All reports from the field indicated slabby conditions.
Avalanche Summary
A widespread natural avalanche cycle started overnight on the 19th. Numerous size 2.5-3 avalanches occurred in paths along the highway east and west of Rogers Pass. Most notably, Laurie, Junction E, and Crossover slidepaths had size 3 avalanches running into the fans with some running right into the creek in the valley bottom.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.