Wind slabs in the alpine remain the dominant concern. Cornices have grown large in recent days, and may be the prime trigger for slab avalanches.
Weather Forecast
A frontal system moving across the interior today will produce light precipitation, while winds ease off. Up to 5cm could accumulate over higher areas. Skies will be mostly overcast with some sunny breaks. A ridge will move in on Friday, bringing drier conditions and a bit more sun.
Snowpack Summary
Soft and hard slabs have formed in the alpine and treeline, mostly on lee aspects (N and E), from wind transported storm snow. On solar aspects, these slabs overly a sun crust (formed on Feb. 3rd) and overlies firm old snow elsewhere. The mid-pack is generally strong, but has become weaker in shallow areas and around trees and rocks.
Avalanche Summary
Avalanche control operations in the park yesterday produced 30+ avalanches on all aspects. Most of these involved surface soft slabs, running to end path or the top of the fans. Two larger avalanches ran to the highway. There were no recent reports of avalanches in the back country, and permit areas were closed yesterday for control work.
Confidence
Due to the number of field observations
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.