New snow & wind may form reactive wind slabs near ridgetops.
Remain especially cautious on high northerly slopes & areas without a thick supportive crust under the new snow.
New snow and wind may be forming fresh wind slabs on lee features. Keep in mind that wind slab may step down to deeper weak layers resulting in larger avalanches.
The persistent weak layer has produced several large to very large avalanches in recent days. It remains a concern where there is no thick, supportive crust under the new snow.
Sun: Several small loose wet avalanches were ski cut and one size 2 natural avalanche occurred near Castle Mtn.
Fri /Sat: Naturally triggered size 2.5 persistent slabs occurred near Castle Mtn. They ran on the persistent weak layer, approximately 50 cm deep.
Looking forward: Fresh wind slabs may be reactive and have potential to step down to deeper layers on Wednesday.
Up to 15 cm of new snow is expected to fall overnight and through Wednesday. Southwesterly winds may build fresh and reactive wind slabs on lee north and easterly slopes. The new snow will be falling on a widespread melt-freeze crust that exists everywhere but high north-facing slopes. The main feature of the region's overall shallow snowpack is a persistent weak layer of surface hoar or facets from late January now buried 40 to 60 cm deep (see photo below). This layer was active during the warm-up and remains a concern where a thick and supportive crust under the new snow hasn't stabilized the snowpack.
Tuesday Night
Cloudy with 2 to 5 cm of snow. 25 km/h southwest ridgetop wind. Treeline temperature around -6 °C. Freezing level 1600 m, then falling to valley bottom.
Wednesday
Cloudy with 2 to 10 cm of snow. 10 to 25 km/h west ridgetop wind. Treeline temperature around -3 °C. Freezing level rising to 1600 m.
Thursday
Mostly sunny. 10 to 15 km/h northeast ridgetop wind. Treeline temperature around -1 °C. Freezing level rising to 1800 m.
Friday
Sunny. 20 km/h west ridgetop wind. Treeline temperature around 1 °C. Freezing level rising to 2000 m.
More details can be found in the Mountain Weather Forecast.
