Observations from the high alpine (above 2300m) have been very limited. Dig down and test for weak layers before committing to steeper, exposed lines.
Weather Forecast
Expect a mix of of sun and cloud for the forecast period. Winds are forecast to remain light to moderate from the northwest, switching to southwest on Thursday and Friday. Freezing levels should hover at 1200m on Wednesday, rise to 1800m on Thursday, and fall back to 1200m on Friday.
Avalanche Summary
On Monday, a size 2 persistent slab avalanche was remotely triggered from a distance of about 100m in the far north of the region (Goldbridge area). The avalanche occurred at about 2300m in a wind-loaded area and failed on surface hoar buried about 70cm below the surface. The remote triggering points to the touchy nature of the instability in this area. No other avalanches were reported.
Snowpack Summary
Up to 50 cm of settled storm snow has been saturated by rain up to about 2100m. With more recent cooling, most surfaces will now be refrozen. At the highest elevations you might find dense, stubborn wind slabs in lee terrain. New cornice development has also been noted. The older storm snow overlies a hard crust and/or surface hoar layer which formed in early January. The bond at this interface will be largely elevation dependant as rain may have penetrated the snowpack enough to dissolve the crust in many areas. In the north of the region, snowpack tests indicate this interface is still sensitive to triggering in some areas.Deeper snowpack weaknesses seem to have become unreactive, and should become even less of a concern if the forecast cooling trend verifies.
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.
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.