Still waiting for spring conditions! Unfortunately this leaves us in a low probability, high consequence conditions.
Weather Forecast
An unorganized weather pattern is upon us We could see 1cm to 10cm of snow above 1900m, winds are currently mod-gusting to strong from the NE, but are forecasted to switch to the SW today and stay in the Mod range. FL may hover near 1900m or could start cooling after lunch depending which forecast to believe.
Snowpack Summary
5cm of new snow overlies a series of crusts on most asp up to 1900m. Polar asp will be holding the best quality snow @ upper treeline and above. A snow profile on Mt Fidelity yesterday showed a HS of 325cm, snow was dry throughout and little to no results on snow pack tests.
Avalanche Summary
No new avalanche activity observed in the highway corridor yesterday (but we had poor visibility). TRU observed a natural cornice to size 2 in the Perley area and our neighbors are still observing large natural avalanches. Earlier in the week cornices were failing and a few storm slabs and loose wet slides to size 2.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
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.