Regions
Northwest Coastal.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
Tuesday: Light precipitation. Freezing level around 1600 m. Light southerly winds.Wednesday/Thursday: Light precipitation. Freezing level around 1900 m on Wednesday and 1500 m on Thursday. Light southerly winds.
Avalanche Summary
Recent reports include wet loose avalanches up to size 2.5 in response to warming and sunshine. Large glide avalanches also continued. On Saturday, a size 3 glide release removed trees and left a 4-5 m deep deposit near Shames.
Snowpack Summary
A melt-freeze crust exists on solar aspects and at low elevations. In some areas, limited overnight cooling has kept surface snow from re-freezing, leaving it loose and cohesionless. Surface hoar exists on shady slopes up into the alpine. Dry settling or faceting snow can be found on high north aspects. Pockets of wind slab formed with recent easterly outflow winds. Glide cracks have opened up and pose the threat of full-depth releases, especially on steep rocky terrain features.
Problems
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
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.