Avalanche Forecast
Issued: Dec 20th, 2013 8:38AM
The alpine rating is Wind Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Due to the number of field observations
Weather Forecast
Saturday: Mainly cloudy with a chance of flurries. The freezing level could jump to 700 m and moderate gusty west-northwest winds continue. Sunday: Possible sunny breaks and flurries. The freezing level could climb to 1000 m and the upper flow continues to be northwesterly. Monday: Cloudy, light flurries, with freezing level rising to 1200 m in some parts of the forecast area. Winds from the west.
Avalanche Summary
Several natural and skier accidental . There was also a report of a size 3 natural slab avalanche from a southwest-facing alpine slope that ran full path.
Snowpack Summary
Wide variation in snow depths between north and south in the South Columbias. 5-10 cm of dry new snow covers the previous storm snow and wind slabs in higher exposed terrain. Dense wind slabs are most likely on exposed north through southeast facing slopes. A weak layer of surface hoar, facetted snow, and/or a crust is now down around 40 cm in the south and up to 60 cm further north. This layer has recently been reactive to riders and natural triggers and both cracking and whumpfing have been noted. The late-November interface, which consists of a sun crust on steep south facing slopes and surface hoar in sheltered areas, is buried 60-90cm below the surface and is generally considered to be "stubborn" to trigger. At the base of the snowpack the October crust is lurking in specific terrain, like north-facing alpine slopes with smooth ground cover. Triggering this weakness is unlikely, but if triggered the resulting avalanche would be very large and dangerous.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 21st, 2013 2:00PM