Summary
Confidence
Fair - Intensity of incoming weather is uncertain on Monday
Weather Forecast
Sunday: a mix of sun and cloud with light snowfall - moderate southwest winds - freezing level at 950m Monday: heavy snowfall continuing overnight - strong to extreme southwest winds - freezing level between 1000 and 1500m Tuesday: light snowfall with possible clearing - moderate southwest winds - freezing level at 700m
Avalanche Summary
Numerous natural and human-triggered slabs to size 2.5 were observed in the Duffey lake area over the last few days. The suspected sliding layer has consistently been the March 26th interface. On Face Mountain in the Railroad Pass area 2 sledders triggered a size 2 avalanche while riding the slope at the same time. The slide was 60m wide and 50cm deep and was most likely triggered on the March 26 layer. The sledders escaped without injury.
Snowpack Summary
40-60cm of new snow now overlies an interface that was buried on March 26. This interface consists of a crust that exists on all aspects and elevations except north facing slopes at treeline and above where small surface hoar (5mm) may be found in sheltered areas. This week's snowfall has been accompanied by consistently moderate and at times gusty southerly winds forming windslabs in lee locations. The bonds between the new snow and this buried interface have been weak, especially in locations where the surface hoar is present. Easy planar results have been observed in testing at treeline on surface hoar size 2-4mm. At lower elevations, the consistent high freezing levels have kept the new snow moist and heavy. The deep, persistent early February layers linger in the snowpack and remain a concern with heavy triggers and rapid loading. Cornices are huge, and have continued to grow with this weather pattern.
jlammers,
Avalanche Canada
