Strong winds and rising freezing levels are keeping the danger elevated. Start simple and continually assess wind-drifted areas and monitor the bond of the recent snow.
Strong southwest wind has drifted recent snow into reactive wind slabs on lee terrain features. These wind slabs will be likely to trigger on Sunday, particularly in areas where they formed over a crust, facets, or surface hoar.
Rising freezing levels may bring rain rather than snow at lower elevations. Wet loose avalanches may be widespread, especially from steeper slopes with an underlying crust.
Saturday night: Cloudy, isolated flurries with trace accumulations, strong southwest wind with extreme gusts in the alpine, treeline temperatures near -4 C, freezing level near 1000 m.
Sunday: Cloudy with sunny breaks, isolated flurries with trace accumulations, strong southwest wind with extreme gusts in the alpine, treeline high temperatures near -1 C, freezing level rising to 1400 m.
Monday: Mainly cloudy, 5-15 cm of snow, moderate west winds increasing to strong in the alpine, treeline temperatures dropping from -3 C to -5 C, freezing level dropping to 1000 m.
Tuesday: Mainly cloudy, scattered flurries with up to 5 cm of snow, strong southwest winds, treeline high temperatures near -2 C, freezing level rising to 1300 m.
On Saturday, operators in the south of the region reported large (size 2-2.5) avalanches releasing naturally in wind-loaded areas.
Earlier in the week, there were reports of natural and skier triggered loose dry sluffing and a few small soft wind slabs (up to size 1.5). On Thursday, small (size 1) loose wet avalanches were observed below 1300 m in the west of the region.
A substantial wind event took place Friday night. Strong southwest winds have drifted 30-45 cm of recent snow into slabs that will be likely to trigger. These slabs formed over a variety of surfaces including facets, surface hoar, hard slab and in the southwest part of the region, a rain crust up to 1500 m. Investigate these underlying surfaces for a poor bond. In exposed alpine areas in the Telkwas, extensive wind effect has created supportive, hard surfaces.
Freezing levels are forecast to rise on Sunday. Use extra caution around treeline areas experiencing above freezing temperatures for the first time.
Deeper in the snowpack, we are still tracking two persistent weak layers. The first is a surface hoar layer from mid-January buried down 50 to 70 cm. The second is a layer of facets from early January that can found down 70 to 90cm. This layer has been most reactive where wind slabs have formed above, and a large load will likely be necessary to trigger it.
