Eaglecrest had numerous small slab avalanches today, all soft slabs,both explosive and human triggered, and all in the smallest relative size 1 and destructive size 1 categories. Though many were 50 cm thick and easily released, the fractures were not propagating beyond 5 to 20 m wide.

The likely reason for the small size of the slabs today is that the underlying bed surface and the windloading of the slab both had high spatial variability. Some areas were scoured to the December 23 to 24 thaw crust, while others had deep heavy drifts.

The most sensitive slabs were in protected areas where facets and surface hoar remained to function as weak layers.

Areas underlain by the December 23 to 24 faceted melt freeze also released, but the rough, eroded ice surface provided more mechanical keying than melt freeze crusts often do. Faceted melt freeze crusts tend toward high spatial variability, being hard and rough in places, slick in others, and sugary in others.

The old windslabs from clear weather Northeasterlies a week ago seemed to be the least sensitive bed surface.

We also did the standard observation rounds of the Juneau area urban paths today and were surprised to find no visible debris at all despite some 50 cm of new snow on a weak snowpack in the last 24 hours, accompanied by strong SE winds to 15 m/sec. This strongly suggests that the higher elevation starting zones of the larger paths have a bed surface of rough faceted melt freeze and old windslab that will hold the slabs until there is additional load. Observations of strong wind transport and erosion on the mainland ridges during the last cold clear period suggest that any facets and surface hoar would have been eliminated by the persistent winds.

The weather forecast calls for additional heavy snow and winds over the next week, and some rising temperatures. Snow levels are expected to remain below starting zone elevations, so rain triggered cycles are unlikely, but warmer denser snow on top of the current dry snow may tip the balance if windloading and rapid loading of dry new snow do not do it sooner.

It is difficult to predict how long it will be before a rapid change will initiate the expected avalanche cycle under these conditions, but the longer the cycle delays the more snow accumulates, and the more snow there is the bigger the slides will be.

The Juneau area mainland paths should not be trusted this week, especially during periods of heavier snowfall, wind, or rising temperatures, and the starting zones that form bowls to catch drifting snow are likely to release first.

Backcountry travelers and ski area hikers during these closed days should be extra cautious. Slopes over 35° will probably release when ridden. Keep your slope angles low and beware if the slabs start becoming continuous over larger areas, or if loading increases.

The recent rash of avalanche accidents in the other states is due to snowpacks much like ours, with ice crusts from thaws and layers weakened and faceted from long cold periods, being loaded by big dumps. People with pent-up powder longings are easily tempted into unstable conditions when the riding is good after a long dry spell. Take care with your timing, terrain choices, and travel procedures.