Regions
Northwest Inland.
Cornices remain the primary concern. Solar radiation is a common cornice trigger. Limit your exposure when it's cloudy and completely avoid cornices when it's sunny.
Confidence
Moderate - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
Unsettled weather continues throughout the forecast period. MONDAY: Mix of sun and cloud with isolated flurries (2-5cm). Light southeasterly ridgetop winds. Freezing level around 1500 m.TUESDAY: Scattered flurries (5-10cm). Light northerly ridgetop winds. Freezing level around 1400 m.WEDNESDAY: Mix of sun and cloud with isolated flurries (2-5cm). Strong easterly ridgetop winds. Freezing level around 1400 m.
Avalanche Summary
No new reported on Friday or Saturday.On Thursday several natural cornice releases (to Size 2.5) were reported in the north of the region.
Snowpack Summary
Small amounts of new snow (3-5cm) fell on Saturday. Winds were light to moderate (south through northeast) and may have created small wind slabs on lee features below alpine ridgetops. The new snow will likely be sitting on hard surfaces created by strong winds earlier in the week. Elevations below roughly 1300 m are experiencing a daily melt-freeze cycle and the snowpack is likely isothermal. The February crust and facet layer is 70-90 cm deep in the Houston Telkwas sled area and a deep persistent faceted weak layer is still lingering near the bottom of the snowpack in all areas.
Problems
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.
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.