Regions
Northwest Inland.
Confidence
Fair - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
Friday: Continued light snowfall / Strong southwest winds / Freezing level at 800mSaturday: Light snowfall becoming moderate overnight / Strong southwest winds / Freezing level at 900mSunday: Light snowfall / Moderate to strong southwest winds / Freezing level at surface
Avalanche Summary
No new avalanches were reported. Activity in neighboring regions suggests there may have been a round of storm slab activity to size 2 in deeper snowpack areas in response to recent wind and snow.
Snowpack Summary
Between 20 and 45cm of recent storm snow overlies a medley of old surfaces which include: weak surface facets, surface hoar, a scoured crust, or any combination thereof. Reports from the field indicate a poor bond between the new snow and these old surfaces. I would expect the developing storm slab to be mostly reactive in the deeper snowpack areas, or in exposed terrain where the new snow has been shifted into wind slabs. Forecast warming may also add cohesion to the slab contributing to its reactivity.The mid snowpack is generally strong and well-settled. Basal facets and depth hoar are likely to exist in some areas, but triggering is only a concern in thin and variable snowpack areas with large triggers.
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.