Conditions are changing quickly. With heavy snowfall expected today, storm slabs will become touchy!
Weather Forecast
Snow is on the way!! Today we can expect 10cm with another 10-15 tonight. Ridgetop wind will be from the SW at 20kph with freezing level up to 800m. Monday we will see the precipitation ease before another weather system brings moderate precip to Rogers Pass Tuesday.
Snowpack Summary
15cm of new snow fell in the last 48 hrs burying the Dec15th interface. This layer is the one to watch develop. It is widespread surface hoar found at all elevations and is LARGE (30-40mm) in sheltered areas at treeline. The new snow also buries crusts on S & W aspects and windslab in the alpine. The Nov crusts, buried down ~70cm are bonding well.
Avalanche Summary
Reports yesterday came in of a skier triggered sz 1 storm slab on the fan of Cheops North 5. It propagated 50m wide and was up to 30 cm deep. Expect to see more avalanches like this but larger as we get more snow or the new settles into a slab on the Dec 15th surface hoar.
Confidence
Intensity of incoming weather systems is uncertain on Sunday
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.