Avoid avalanche terrain during periods of heavy loading from new snow and wind.
Weather Forecast
Light snow is forecast today, with around 5 cm of accumulation. Freezing levels will rise to around 1300m. Ridge top winds continue to be SW 40 gusting to 70. Only trace amounts of snow are forecast for tomorrow, with a return to light snow on Tuesday. Temperatures will slowly fall over the forecast period.
Snowpack Summary
40-50cm of storm snow sits over the December 8 surface hoar layer at lower elevations and over variable wind slabs up high. The storm snow is rapidly settling into a slab with warm temperatures and moderate to strong winds. The November 28 surface hoar is down around 60-80cm.
Avalanche Summary
We observed a small natural avalanche cycle along the highway corridor yesterday. The majority of the avalanches were size 1.5 to 2.5 from all aspects depositing snow into runnouts. Two size 3.0 avalanches were observed both east and west of Rogers Pass.
Confidence
Due to the number of field observations
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.