Avalanche Bulletin
更新日時: 2025/03/09 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
The overall trend is that the instability caused by the snowfall of the past few days is dissipating, but caution should still be exercised on unstable slabs that remain in certain terrain pockets. Be on the lookout for isolated avalanche-prone terrain, such as convex slopes where the snowpack has the characteristics of a slab. Melt-Freeze crusts under fresh snow can increase the risk of even small avalanches. Hard crusts are exposed on ridge tops and in other areas where the wind is strong. Be careful of slips and falls. With cooler temperatures this morning, simple terrain on the north side of the mountain will allow for safe fresh snow skiing. Have a good day.
Avalanche Problem
ウインドスラブ Wind slab
Watch for unstable slabs that remain on isolated terrain that is convex and unsupported. Also, remember that although time-lapsed wind slabs have increased in hardness, the steep slopes that are exposed to strong solar radiation today may increase in triggering sensitivity during the day.
ストームスラブ Storm slab
Watch out for unstable slabs that remain in terrain pockets on very steep slopes that are not affected by the wind.
点発生湿雪雪崩 Wet Loose snow
Rating is as of morning. Caution on steep slopes at lower elevations that receive strong solar radiation during the day.
概要
Avalanche
Yesterday (8th), several size 1 storm slab avalanches were observed in the below treeline.
Snowpack
There is 20-30 cm of new snow on top of the Melt-Freeze crust (formed by rainfall on March 5). This new snow was affected by strong winds the day before yesterday (March 7) and high temperatures yesterday (March 8). Melt-Freeze crusts are exposed in areas where the wind is strong, forming wind slabs on the leeward side. The amount of new snow is higher in the northern part of the Hakuba Valley, and yesterday's solar radiation and temperatures have promoted settling below treeline. Information on the bonding of crusts and new snow at higher elevations is lacking and highly uncertain.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy, sunny before noon, and a daytime high of 7 °C (418 m elevation) for northern Nagano Prefecture. At the AMeDAS Hakuba (elevation 703 m), the temperature is -3,9 °C (as of 5:00 am), with 3 cm of snow having fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -12 °C (as of 5:00), with northerly winds averaging 7 m/s and a maximum instantaneous wind speed of about 9 m/s.
