Snowfall totals by Thursday midday were less than forecast and with calm wind conditions little redistribution of snow was occurring. Watch for rising temps and the influences of daytime heating over the next few days as warmer weather moves in.
Weather Forecast
Barometric pressure will rise steadily on Friday as a ridge of HIGH pressure moves into the area. Light flurries over Thursday night tapering off Friday AM with skies expected to clear as the day progresses. Light to moderate NW winds and alpine temps ranging from -8 to -12. Valley bottom temps a few degrees warmer and winds generally light from the West.
Avalanche Summary
Widespread sluffing of loose dry storm snow on steep lee aspects in the alpine elevation zone through the day on Thursday. No other avalanche activity observed or reported.
Snowpack Summary
8cm of new snow by Thursday morning at treeline with an additional 3-5cm through the day. Winds generally calm all day with brief sunny periods depending upon location. The storm slabs are slowly settling and bonding to previous surfaces and the lack of wind is slowing the pace of softslab formation and cornice growth.
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.
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.