Avalanche Forecast
Issued: Dec 23rd, 2017 4:24PM
The alpine rating is Wind Slabs and Loose Dry.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
SUNDAY: Cloudy, flurries. Accumulation 2-5 cm. Ridge wind moderate from the west. Temperature -9. Freezing level surface. Strong outflow winds near coastal valleys.MONDAY: Mostly cloudy, flurries. Accumulation trace. Ridge wind light from the north. Temperature -9. Freezing level surface.TUESDAY: Mostly sunny. Ridge wind light. Temperature -10. Freezing level surface.
Avalanche Summary
There were no new reports of avalanches on Thursday although whumpfing in hard wind slabs on cross-loaded features at treeline was observed in the northern part of the region. On Wednesday the Coquihalla and Allison Pass areas saw numerous loose dry to Size 1.5, as well as slab and glide avalanches to Size 2 on steep, leeward terrain and smooth rock slabs. Reports from the northern part of the region indicated wind slab activity up to size 2 on north and west aspects in the alpine.In the southern part of the region classic signs of instability such as whumpfing and shooting cracks have also been reported here in the MIN.
Snowpack Summary
The recent storm snow has been redistributed by moderate to strong northerly winds in the alpine and exposed treeline areas, creating wind slabs in some areas and scouring others (particularly in the northern part of the region).The southern part of the region has seen impressive storm snow totals (80-100cm) since Sunday night, compared to northern areas of the region, which received 25-35cm. This new snow sits on crusts of variable thickness that formed on almost all aspects in mid-December (December 15th layer). On steep southerly aspects the crust is supportive, whereas on northerly aspects the crust is quite thin and variable. Beneath the December 15th layer the snowpack is well settled. The late November rain crust is now buried 50-80 cm in the northern part of the region and well over 1 m in the south. Great conditions reports from the north of the region on the Mountain Information Network (MIN) here, as well as from the southern part of the region, here.
Problems
Wind Slabs
Aspects: North, North East, East, South East, South.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 24th, 2017 2:00PM