Avoid complex and wind-loaded terrain.
Storm slabs will be building throughout Sunday.
Persistent weak layers of surface hoar/facets or crust remain a concern in the upper 50 - 100 cm. Storm slab avalanches could step down to these layers, forming very large avalanches.
Storm slabs will be building through Sunday and expected to be most reactive on north through east facing wind-loaded slopes at upper elevations.
Fri: A very large size 3 persistent slab occurred near Blue River on a south-facing treeline slope.
Thurs: A very large (size 2.5) dry loose avalanche happened near Blue River on a south-facing alpine slope.
Wed: Two small (size 1) skier-triggered wind slabs occurred at treeline on a northeast-facing slope
With new snow and wind in the forecast, we expect storm slabs to become increasingly reactive on Sunday.
Up to 25 cm of new snow is expected to fall overnight and through Sunday and will build widespread new storm slabs. Due to forecast winds, these slabs are expected to be thickest and most reactive on wind-loaded north and east-facing slopes. Snow may be moist or wet at lower elevations.
Three persistent weak layers consisting of surface hoar, facets, or a crust may be found in the upper to mid-snowpack:
The early March layer down 50 - 100 cm. This is the primary weak layer of concern.
Mid-Feb layer down 70 - 150 cm.
Late-Jan layer down 120 - 180 cm.
The lingering concern for the Feb and Jan weak layers is in shallow or rocky areas, otherwise, these are unlikely to trigger without a significant load.
Saturday Night
Mostly cloudy with 0 to 5 cm of snow. 20 to 30 km/h southwest ridgetop wind. Treeline temperature -8 °C.
Sunday
Cloudy with 10 to 20 cm of snow, up to 15 cm coming Sunday night. 35 to 45 km/h southwest ridgetop winds. Treeline temperature -2 °C. Freezing level rising to 1500 m.
Monday
Cloudy with 0 to 5 cm of snow / light rain below 1500 m. 15 to 30 km/h west ridgetop wind. Treeline temperature 0 °C. Freezing level rising to 1900 m.
Tuesday
Cloudy. 15 to 20 km/h south ridgetop winds. Treeline temperature +2 °C. Freezing level rising to 2100 m.
More details can be found in the Mountain Weather Forecast.
