Sea To Sky

Two incidents Saturday remind us that a potentially dangerous storm/wind slab remains sensitive to human triggering. Caution and restraint is urged at this time. Take a conservative approach as you travel in the mountains Sunday.

Moderate - Wind effect is extremely variable

An unsettled pattern opens the door to a string of relatively small low-pressure systems that should deliver modest snowfall to the region throughout the forecast period. Cold air currently in place will help to keep freezing levels low, at least through Tuesday. All bets are off Wednesday, when the weather models show an influx of moist warm air that will likely push the freezing level up towards 1800m and deliver 20 to 40mm of precipitation. SUNDAY: Overcast skies, freezing level near valley bottom rising to 500m in the afternoon, light SW wind, 1 to 5cm of snow. MONDAY: Overcast skies, freezing level around 500m, moderate SW wind, 1 to 5cm of snow. TUESDAY: Overcast skies, freezing level rising to about 700m in the afternoon, strong SW wind, 10 to 20mm of precipitation expected. Visit avalanche.ca/weather for a more detailed mountain weather forecast.

There were two significant avalanche accidents on the South Coast Saturday. Please recognize that at the time of writing, details are sparse, and in an evolving situation like this some information may prove to be incorrect. The first incident occurred west of Whistler in the Sea-to-Sky region. Initial details suggest the avalanche occurred on a west-facing feature. Size is estimated to be 2 to 2.5, approximately 80m in width with a 100cm crown. One critical burial was reported. The second incident occurred in the South Coast region where one person was reported to be fully buried in a feature called the Tony Baker Gully near Cypress Mountain. North Shore SAR has removed the person from the scene with reportedly serious injuries.These incidents serve as reminders that dangerous conditions still exist and caution is required when planning and carrying out trips in the region.On Saturday control work produced avalanches to size 2.5 on a variety of aspects with crowns averaging 20 to 40cm in depth. One natural size 2.5 avalanche was reported on a NE facing feature between 1900 and 2450m. Widespread sluffing was also reported.

Strong winds out of the south/southwest have taken the 20 to 70cm of recent storm snow and formed it into a reactive slab. Recent observations suggest this slab ranges from 20 to 100cm in depth throughout the region, but it could easily be twice that deep on lee features at and above treeline. This slab is currently bonding poorly to the old surface which includes scoured crust, hard sastrugi, stubborn wind slabs and up to 20cm of facets in sheltered areas. Just below this interface is the mid-February crust which remains active. This crust is 50 to 80cm below the surface on average, it should be easy to find and test in your profiles. Recent snowpack tests continue to show sudden results in facets above this crust. The mid and lower snowpack are well settled and strong.