Tenki and Yuki Diary 17 Feb 08

Know the weather = know the snow pack = know the stability.

Steep Deep Japan Hakuba  weather data for the 24 hours to 7am for 860m asl Max temp -1C, min temp -8C and  -7C at 7am. 15cm of new snow in the last 24 hours with a density of 81kg/m3, equivalent to 8.8% water - getting lighter.  Barometer steady at 914mbar.  Wind aloft is moderate from the north west and snow is falling at a rate of 2-3cm per hour.  The storm continues. With lower altitude tree terrain accumulating a lot of powder without mush evidence of the windslab which is a problem at Tree Line and in the Alpine

Field observations:  Yesterday we travelled in the backcountry to 1600m asl in the Otari area.  Moderate to strong gusts from the NW.  The rate of snowfall increased into the afternoon to about 3cm per hour. We found a lot of deep dry stable powder on northerly aspects.  Several groups, private and guided, mutually confirmed the stability on the day in that area. A Japan Avalanche Network public weather and snow stability report can be found here.  Please use this valuable resource provided by JAN.

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