Recent snow, since Christmas, may not be bonding well to the underlying crust in some areas.
Significant amounts of snow have accumulated since Christmas and may not be bonding well to an underlying crust in areas. Wind-loaded terrain at treeline and above is the most likely place to trigger a slab avalanche.
Explosive control work on Wednesday produced mostly small slab avalanches (size 1–1.5) in alpine terrain. Despite a strong, artificial trigger (explosives), these avalanches showed minimal propagation.
Numerous small skier-triggered avalanches occurred on Monday, failing on the Dec. 25 crust. Most of these avalanches occurred on northerly terrain around treeline elevations.
Light snow on Friday will begin to bury a variety of old surfaces, including surface hoar in wind-sheltered terrain and a sun crust on south-facing slopes at treeline and above.
Since Christmas, approximately 30 to 50 cm of snow has accumulated over a melt-freeze crust that is thin or absent in alpine terrain but thicker and more widespread at treeline and below.
The mid and lower snowpack is generally well bonded and consolidated, with multiple crust layers present.
Thursday Night
Mostly cloudy. Trace amounts of snow. 30 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Friday
Cloudy. 2 to 5 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -4 °C.
Saturday
Cloudy. 15 to 30 cm of snow. 40 km/h south ridgetop wind. Treeline temperature -2 °C.
Sunday
Mostly cloudy. 10 to 20 cm of snow. 40 km/h south ridgetop wind. Treeline temperature -2 °C.
More details can be found in the Mountain Weather Forecast.
