While it feels like spring in the valley, the alpine has returned to winter. Stay on your toes as a potentially touchy storm/wind slab likely exists at upper elevations.
Weather Forecast
SUNDAY: Freezing level starting at 1000m rising to 1700m. Light W/SW winds at treeline, Moderate W winds at ridge-crest. Scattered cloud. Isolated flurries, no significant precipitation expected.MONDAY: Freezing level starting around 1300m, rising to 2000m. Light SW winds at treeline, moderate SW winds at ridge-crest. Few clouds in the morning building to overcast in the afternoon. Scattered afternoon flurries with 2 to 10cm of snow possible Monday night.TUESDAY: Freezing level around 1400m. Light W/NW winds at treeline, moderate NW winds at ridge-crest. 1 to 5cm of snow possible during the day. Broken cloud cover.
Avalanche Summary
Several cornice falls have been reported in the last few days, some of which have triggered slabs on slopes below, some which have not.
Snowpack Summary
The region picked up around 5 to 15cm of snow Friday night accompanied by strong SW winds burying the old surface which consists of facets, surface hoar and crust. Prior to Friday nights storm the 10 to 25cm that fell the weekend of April 4th remained dry on north facing features above 2300m while corn was starting to form to ridge top on south facing aspects. East and west facing features had turned moist.Down 15 to 40cm you will find the supportive late-March crust that is thought to exist up to around 2100m. Moist snow underneath the late-March crust is ubiquitous in most of the region.Persistent weak layers in the mid-pack remain a lingering concern, although they seem to have gone dormant for the time being. In the north of the region, the mid-March crust/facet layer is down 45 to 75cm and the mid-February crust/facet/surface hoar layer is down 80 to 90cm. While weak layers formed earlier in the winter remain intact, they too are dormant at this time.
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 Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.