Avalanche Forecast

High - The weather pattern is stable

Thursday: Mainly cloudy with isolated flurries and a trace of new snow. Winds light from the west. Freezing level to 1000 metres and alpine temperatures of -5. Friday: Mainly cloudy with isolated flurries and a trace of new snow. Winds moderate from the southwest. Freezing level to 1100 metres and alpine temperatures of -3 Saturday: Cloudy with sunny periods. Winds moderate gusting to extreme from the southwest. Freezing level to 1200 metres with alpine temperatures of -1.

Some successful explosives cornice control took place in the Whistler area on Tuesday. A few of the resulting large chunks of cornice did manage to trigger slabs below to the full depth of our storm snow, giving an idea of the reactivity that still exists in the snowpack when a big trigger is in play. With that said, failures at this layer could be described as 'low probability, high consequence' and wind slabs still form our primary avalanche hazard over the near term. A MIN report from Tuesday additionally highlights the tendency for unconsolidated storm snow to sluff easily in steep terrain, entraining loose snow into dangerous flows that require careful management.

A highly variable 70-140 cm of storm snow now forms our upper snowpack, the product of a storm that rapidly blanketed the region late last week. Wind slabs developed on a range of aspects at exposed higher elevations in the days after the storm and these wind slabs remain our primary avalanche hazard. Aside from wind slabs, the storm snow has been described as 'right side up' (lower density at the top) and is settling quickly with the aid of continued mild temperatures. While this inspires some confidence, a number of easy sudden planar results on density changes in the storm snow were observed in the Spearhead range as recently as Monday, suggesting that investigation of the storm snow is still called for in bigger terrain. The bond of our storm snow to the varied surfaces below it has been improving, with this interface producing moderate to hard and generally resistant snowpack test results. The mid and lower snowpack are generally well settled but still feature a number of facet and crust layers that warrant long term monitoring.