Tenki and Yuki Diary 31 Jan 08

Steep Deep Japan Hakuaba  weather data for the 24 hours to 7am for 860m asl Max temp +5C, min temp -5C. Barometer 911mbar and steady.  8cm new snow with a higher density of 88kg/m³ (9.6% water). Wind is light in the valley, but most likely moderate in the peaks.

Field observations in the Goryu area for the last 24 hours: my JAN report can be found here.  I encourage people to use the valuable resource provided by JAN.  Between 1900m and 1600m asl we experienced 30cm of dry snow sitting on a thick freeze thaw base.  This new snow was loose and sluffing easily.  Below 1600m the new snow depth was 20-30cm and warmer, thus forming more cohesive soft slab avalanches up to size 2 (enough to bury a person).  Every convex roll above 30 degrees would slide.  In fact, anything above 30 degrees would slide, however typically only 10cm of surface snow, size 1 avalanches.  It was a bad day to be in the backcountry and we remained carefully on a ridge line for almost the entire descent.  The top 100cm of north facing snowpack seemed to be made up of 30-40cm new snow on top of 40-50cm of spring-like melt-freeze base.  An so far nothing is sticking to it.  I still also strongly suspect that the surface hoar from 080128 is buried under 30cm of snow in shaded and wind protected pockets.

Please also refer to the Hakuba backcountry travel advisory from the guides at Evergreen Outdoors.

Hakuba weather forecast for the next 24 hours:  overcast, clearing slightly, light snow, colder and windier than yesterday.