Wind slab reactivity may increase during periods of strong solar effect and mild alpine temperatures.
Wind slab sensitivity may increase with warming alpine temperatures.
Surface slabs may sit above layers of weak surface hoar, prolonging their reactivity.
Widespread sluffing in steep, south-facing, high alpine terrain was reported on Sunday, during periods of direct sun.
Several wind slab avalanches have been reported in recent days, triggered by a variety of factors. Most of the avalanches have occurred around ridge crests and on multiple aspects. Notably, some slabs failed on a buried surface hoar layer, located 30 to 40 cm deep.
Surface hoar growth continues on north-facing and shaded slopes, with conditions on south-facing or sun-exposed slopes varying from crusty to moist, depending on the time of day.
The upper snowpack is largely low-density and faceted with variable old wind-affect in exposed terrain.
Multiple layers of surface hoar, buried throughout January exist, approximately 20 to 50 cm deep. These layers have begun to show signs of reactivity, particularly in areas where a cohesive slab has formed above.
The mid and lower snowpack remains generally well-settled and strong, with no current concerns or significant instability noted.
Monday Night
Clear skies. 30 to 40 km/h northwest ridgetop wind. Treeline temperature -6 °C and a chance of above-freezing alpine temperatures.
Tuesday
Mostly sunny. 30 to 40 km/h northwest ridgetop wind. Treeline temperature -5 °C and a chance of above-freezing alpine temperatures.
Wednesday
Cloud building with 0 to 2 cm of snow. 40 to 50 km/h southwest ridgetop wind. Treeline temperature -5 °C.
Thursday
Mostly cloudy with up to 10 cm of snow. 40 to 50 km/h southwest ridgetop wind. Treeline temperature -7 °C.
More details can be found in the Mountain Weather Forecast.
