Avalanche Forecast

Moderate -

Thursday night: Periods of snow bringing 15-20 cm of new snow. Moderate to strong south winds. Friday: Continuing flurries bringing another 5-10 cm of new snow. Moderate to strong southwest winds. Freezing level to 1300 metres with alpine temperatures of -3. Saturday: Periods of snow bringing 15-20 cm of new snow. Moderate to strong south winds. Freezing level to 1300 metres with alpine temperatures of -3. Sunday: Flurries bringing 10-15 cm of new snow. Moderate to strong southwest winds. Freezing level to 1500 metres with alpine temperatures of -1.

Reports from Thursday included further observations of reactive wind slabs in immediate lee terrain occasionally releasing to Size 1 under skier traffic and with ski cutting.Reports from Wednesday revealed widespread natural avalanche activity, with Size 1-2.5 releases noted throughout the region. North aspects were most active. Ski cutting and explosives control in the Whistler area yielded numerous results with crown fractures ranging from 20-40 cm deep. Loose snow sluffing from steep terrain was noted on both days. Looking forward to Friday, expect a return to natural storm slab activity and increased human triggering potential. Also, while the bond at mid-February interface remains questionable, the likelihood of large persistent slab avalanches will also increase as forecast snowfall and wind add load to the snowpack.

Moderate to strong southwest wind over Tuesday and Wednesday have redistributed the most recent storm snow and formed new wind slabs in leeward terrain at higher elevations. Another 10-15 cm on Tuesday brought the typical storm accumulation in the past week to 60-100 cm. This snow has settled into a slab that sits over the mid-February weak layer which consists of facets and/or surface hoar overlying a thick crust. In wind loaded terrain, this layer may be down 150 cm or more. Recent observations suggest this layer is still reactive and capable of producing wide propagations if triggered. We have been in an incremental loading scenario over the past week and this layer has not yet been fully tested. Expect it to wake up during the storm on Friday. Below the crust layer, the mid and lower snowpack are well settled and strong.