Avalanche Bulletin
更新日時: 2024/02/27 06:00
Myoko
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Be alert for wind slabs formed by strong winds. Wind slabs can form on the sides and flanks of trails on ridges, as well as large ones that spread across the entire slope. It is common for a climber to trigger a wind slab avalanche when he or she turns slightly to the downwind side to avoid the rocks and wind. In areas where snowfall is increasing, please consider whether there are any large start zones above you and use safe terrain to manage your group wisely.
Avalanche Problem
ウインドスラブ Wind slab
Gusty winds are blowing at higher elevations. Even below treeline, extreme caution should be exercised on slopes where wind-moved snow accumulates.
ストームスラブ Storm slab
There are areas where the winds are lessening and the snow is more likely to accumulate. If it is steep enough there, it is a day for prudent decisions. The lower layer of new snow, where bonding has not increased sufficiently, was observed yesterday.
概要
Avalanche
Yesterday (26th), many avalanches of newly formed wind slabs or storm slabs were reported below treeline. All were caused by ski cuts, etc., and were 1-1.5 in size.
Snowpack
The developing low pressure system is causing fierce winds at higher elevations, which are moving the snow violently. Some areas of poor bonding have been observed between the snow that fell prior to the current snowfall, i.e., at the time of the low pressure system's passage, and the hard old snow (crust or hard snow surface) at its base. The avalanches reported above are locations with such snowpack structure. In areas where there is more new snow, vigilance should be exercised even below treeline.
Weather
The Japan Meteorological Agency is forecasting a northwesterly wind, with a slight wind chill, snow or rain at first, then afternoon, then occasionally cloudy, with a daytime high of 6 ºC (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature is -8 °C (as of 4:45 a.m.), with 10 cm of snow having fallen in the past 12 hours and 20 cm in the past 24 hours.
