Warm air and rain may destabilize the snowpack at lower elevations, with new wind slabs potentially forming up high.
Watch for changing conditions throughout the day and as you move through elevation bands.
Wind slabs may be found in wind-loaded terrain in the alpine and treeline, formed by recent snowfall and westerly winds. These wind slabs will be most reactive where they overlie a slick crust.
Warm temperatures may cause cornices to become weak. Cornice failures are dangerous on their own, but also have the potential to trigger larger avalanches on the slopes below.
Rain and warm temperatures may cause the surface crust to break down at lower elevations. Pay attention to how thick and supportive the crust is, and avoid steep slopes when the crust starts to weaken and become unsupportive to your weight.
SUNDAY NIGHT: Cloudy with snow/rain, 10 cm of accumulation above the rain-snow line. Alpine temperature around -2 C. Ridge winds 10-30km/h northeast. Freezing level 1100m.
MONDAY: Cloudy with sunny periods and flurries, up to 5 cm of accumulation above the rain-snow line. Alpine temperature around -3 C. Ridge winds 15-30 km/h northwest. Freezing level 1500 m.
TUESDAY: Mainly sunny. Alpine high of 3 C. Ridge winds 15-40 km/h southwest. Freezing level rising to 2500 m.
WEDNESDAY: Mainly cloudy with flurries. Alpine temperatures around -3 C. Ridge winds 15-40 km/h southwest. Freezing level rising to 1600 m.
On Saturday, a few small (size 1) natural wet loose avalanches were observed from steep terrain below treeline. Several natural cornice failures occurred that did not pull slabs on the slopes below.
Looking forward, riders may be able to trigger wind slabs in lee terrain features in the alpine and exposed treeline, and wet loose avalanches in steep terrain at treeline and below.
Up to 20 cm of recent snowfall tapers rapidly with elevation. Southwest winds may have formed small pockets of windslab in the alpine and exposed treeline. A refrozen crust can be found below the new snow on all aspects as high as 2400 m. This crust is expected to break down throughout the day at low elevations with rain and warm temperatures. Below the crust, the top 10-30 cm of the snowpack is moist. At very low elevations, the snowpack may become wet and isothermal.
There are no deeper concerns at this time.
