Regions
Northwest Coastal.
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain on Friday
Weather Forecast
Wednesday: Freezing Level: 500m Wind: SW, initially moderate increasing to strong by sundown. 10 - 15 expected during the day.Thursday: Freezing Level: 500m Wind: Strong SW backing off of to moderate SW in the evening. 10 - 20 cm expected during the day.Friday: Freezing Level: 500m Wind: Strong S decreasing to light W after dark. 15 -30 cm expected during the day.
Avalanche Summary
Avalanche activity on Monday was limited to small soft slabs to size 1.5 on both East and West facing aspects. Sluffing continues to occur in steep terrain too.
Snowpack Summary
The most recent storm impacted the region on Friday Feb. 19th with totals in the north averaging around 70 cm, while the south picked up about 20cm. The storm snow has settled out for the most part, and now wind slabs are the main problem. Winds were previously out of the NW, W & SW, and there were even moderate localized winds out of the SE on Monday. As a result, wind exposed slopes in both the treeline and alpine elevation bands feature a wide variety of wind slabs. These slabs have grown less reactive over the last few days, but I suspect you could still find a skier triggerable slab near ridge crest. Cornices that now loom over many features may become weak with continued growth and/or daytime warming.The mid and lower snowpack layers are generally well settled.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.