Avalanche Forecast

Fair - Due to variable snowpack conditions

Synopsis:  Precip amps up Tuesday night but should taper off by Wednesday morning in the northern half of the region.  The southern portion of the region should see significant precip through most of the day Wednesday. The trailing cold front brings freezing levels down slightly with no significant precipitation expected through the duration of the forecast period. Wednesday: Freezing Level: 1300m (North) Precip: 2/5mm – 2/8cm. (South) Precip 15-20mm – 15 -35cm  Wind: Strong, WThursday: Freezing Level: 1000m Precip: Nil Wind: Strong, W/SWFriday: Freezing Level: 1000m Precip: Trace Wind: Mod, SW.

A couple of notable small avalanches were triggered on a large alpine feature in the Pemberton area Monday.  A skier remote triggered a size 1.5 avalanche from 50m away on a NW facing slope that sympathetically triggered another size 1 avalanche.  These are small avalanches, but it's the mechanics that are interesting.  A few small skier controlled avalanches were reported on Sunday. These events occurred in steep terrain at or above treeline and failed within the storm snow just above the recently buried crust/ moist snow.

Recent snowfall amounts vary significantly within the region from north to south. In the Duffy Lake area and north expect to find 20-25 cm of fresh snow, while Coquihalla and Allison Pass areas have seen 50 cm or more. Moderate or strong south or westerly winds left variable snow distribution in exposed areas near ridgetop with dense wind slabs forming in lee and cross-loaded features. The new snow is sitting on moist snow or a melt-freeze crust depending on elevation. Weaknesses exist within the storm snow and the bond between the new snow and crust is questionable. A frontal system passes over the region Tuesday evening which should bring snow above 1500m.  Rain falling below treeline is unlikely to have much affect. Cornices are very large and looming over many ridgelines.