With clearing skies in the forecast, be cautious of heading out into big terrain too quickly. A persistent weak layer is still problematic, and skier triggering remains likely. Don't forget about deep tree wells and cornices.
Weather Forecast
An arctic front will push through the Columbia's today bringing cooler temperatures. A ridge will build behind this, providing clearing skies for later in the day and into the weekend. Patchy snow flurries are still possible, but very little snow accumulation is expected.
Snowpack Summary
Up to 70 cm of storm snow overlies a weak layer of buried surface hoar and facets. This layer is best developed between 1500 and 2000 meters, but exists at all elevations. This layer is also best developed on the eastern side of the park, where surface hoar grew larger than in the west. This variability will make hazard evaluation tricky.
Avalanche Summary
Avalanche control yesterday produced many avalanches, mostly in the size 2-2.5 range. These avalanches primarily involved storm snow. We have had limited observations In the backcountry, however a widespread natural cycle is suspected. Natural avalanche activity will likely subside today, but human triggering is still likely.
Confidence
Due to the number of field observations
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.