Avalanche Bulletin
更新日時: 2025/02/26 05:30
Hakuba
Alpine Fair Lack of information on the amount of snow that can be moved by wind
Treeline Fair
Below Treeline Good Elevated temperature and solar radiation increase danger.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
This is a day when snow conditions change dramatically during the day. Please observe carefully how solar radiation and rising temperatures affect and change the upper layers of the snowpack. Avalanches of wet snow are so heavy that even a small avalanche can scoop a person off his or her feet and knock him or her down. If there is a "terrain trap," such as a cliff, below the slope, the consequences can be serious. Also, stay away from slopes with glide cracks. There is still dry snow on the north side of the elevation gain. Settling powder is easy to speed up, so please ride in a controlled manner. A fall in the mountains can attract all kinds of trouble. Bring sunscreen and plenty of water and have a good day.
Avalanche Problem
ウインドスラブ Wind slab
Yesterday morning (25th), the winds were calm, but they increased in the afternoon. And since last night, extremely strong southwest winds have been blowing on the main ridge. Consider that at higher elevations, new wind slabs are forming on different slopes than yesterday.
点発生湿雪雪崩 Wet Loose snow
Assessment is as of morning. Increased likelihood of occurrence on slopes that are strongly affected by sunny slopes and elevated temperatures during the day.
全層雪崩 Glide slab
Stay away from slopes with glide cracks. Warm air is coming in, so be alert in all directions, not just south at lower elevations.
概要
Avalanche
No new avalanches were observed yesterday (25th).
Snowpack
The storm snow that constituted the upper layer of snowpack proceeded with rapid settling due to yesterday's solar radiation and high temperatures. Dry snow remained on the shaded northern slopes, but Melt-Freeze crusts formed on the slopes affected by sunny slopes. Due to a low pressure system, very warm air began to move in from the south last night. In particular, the temperature has increased by 6.8°C in one hour this morning (-4.2°C at 4:00 to 2.4°C at 5:00). It is necessary to keep in mind that not only solar radiation but also this warm air will significantly change the conditions of the upper layer of snowpack today.
Weather
The Japan Meteorological Agency is forecasting southerly winds, sunny, occasionally cloudy, and snowy in places, with a daytime high of 9 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is 2.4 °C (as of 5:00 a.m.), and no new snow has fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -11 °C (as of 5:00) with southwest winds averaging over 20 m/s.
