Avalanche Forecast
Issued: Dec 25th, 2016 4:07PM
The alpine rating is Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Timing of incoming weather systems is uncertain on Monday
Weather Forecast
Monday: Periods of snow delivering 10-20cm with greater depths in the south of the region. Winds will be moderate gusting to strong from the southwest. Freezing level to approximately 700 metres with alpine temperatures of -8 in the north and closer to -2 in the south.Tuesday: Flurries in the north of the region delivering 5-10cm of new snow with 25cm of new snow expected in the south. Winds moderate gusting to strong from the southwest. Freezing levels to about 900 metres with alpine temperatures of -7 in the north and -2 in the south.Wednesday: Flurries delivering a trace of new snow in the north of the region and up to 10 in the south. Winds moderate gusting to strong from the southwest. Freezing levels to approximately 600 metres with alpine temperatures to -9 in the north and -5 in the south.
Avalanche Summary
Continued potential exists for skier and rider triggering of wind slabs at upper elevations. The possibility of buried surface hoar in isolated sheltered areas and a possible weak bond at the storm/old snow interface also demand careful evaluation. A MIN report from Saturday in the Pemberton Icefield area neatly demonstrates the potential for wide slab propagations on wind loaded features.
Snowpack Summary
A layer of 3-5mm surface hoar has grown on the surface in the Duffey Lake area. Below this, 10-20cm of new snow fell over Thursday and Friday. This new snow has been redistributed in some exposed areas and added to the 30-60cm of storm snow the region has seen since Sunday. In higher elevation and exposed areas, this storm snow formed wind slabs in response to southwest winds. The new snow and wind slabs overlie a variable snow surface from last week that includes hard wind pressed or scoured areas, old wind slabs, weak faceted snow, or surface hoar. In the Duffey Lake area, recent snowpack tests gave hard sudden results down 60 cm at the interface between the recent storm snow and old snow on rounding faceted crystals. The widespread mid-November crust is typically down approximately 1-1.5m. Recent snowpack tests have shown the crust to be unreactive, but it could become a problem in shallow alpine start zones.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 26th, 2016 2:00PM