Avalanche Forecast

Moderate -

Tuesday: Cloudy with continuing flurries bringing approximately 5 cm of new snow. Moderate southwest winds. Freezing level to 900 metres with alpine high temperatures of -6.Wednesday: Mainly cloudy with isolated flurries and a trace of new snow. Light west winds. Freezing level to 700 metres with alpine high temperatures of -7.Thursday: Cloudy with isolated flurries and a trace of new snow, increasing overnight. Light west winds, increasing overnight. Freezing level to 600 metres with alpine temperatures of -8.

Reports from Saturday and Sunday showed ski cutting as well as explosives control in the Whistler area producing numerous storm slab results from Size 1-2, as well as several Size 1.5 cornice releases. The most recent storm interface (down about 15 cm at the time) was noted becoming touchy on Sunday afternoon as temperatures rose and winds increased.Throughout this region there has been evidence of a natural avalanche cycle up to size 3 that occurred within the storm snow on Wednesday. More notable are the numerous explosive triggered, very large avalanches up to size 3.5 that where reported near Whistler on Thursday. Two additional explosive triggered 3.5's were reported Friday. These avalanches started in the storm snow and then stepped down to the early January and even the mid-December crusts which resulted in very large avalanches running full path. They occurred on northwesterly aspects below rocky ridgetops between 1950-2200 m.

Another 30-40 cm of new snow from Sunday through Monday brings recent storm totals to around 110-160 cm. This snow continues to be redistributed by extreme southeasterly winds, creating dense storm slabs in lee and cross-loaded features. Impressive cornice growth has also been observed on the lee side of ridgetops. A crust that was buried in early January is buried 230-280cm below the surface at all elevations. Below this there is another crust which was buried in mid-December. Recent explosive control work has triggered storm slab avalanches that have "stepped down" to both of these crusts, resulting in very large avalanches running full path. Although these layers are over 200 cm beneath the snow surface, large triggers such as a falling cornice or a smaller human triggered avalanche do carry a risk of "stepping-down" to these layers. This risk should be diminishing as temperatures cool over the coming days.