Avalanche Bulletin
更新日時: 2025/02/23 05:30
Hakuba
Alpine Low
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Note the instability that is forming in the upper snowpack. This instability is due to wind and snow from yesterday through this morning. If you find it difficult to assess the situation, please ensure your safety in the terrain by choosing a slope with a gentle angle. When doing so, be careful that there are no large start zones above you. Experienced skiers should consider that "today is a different day from yesterday" and check the snow conditions with fresh eyes. Even if you choose a slope that is less affected by wind, carefully examine its condition, considering the possibility that yesterday's weakly bonding snow may be hidden in the fresh snow. Also, be aware that glide cracks may be hidden by fresh snow at the turn of the slope.
Avalanche Problem
ウインドスラブ Wind slab
Watch for new wind slabs that have formed by this morning.
ストームスラブ Storm slab
Consider the possibility that in areas with heavy snowfall up to this morning, that snow may be buried under yesterday's less cohesive snow. Such slopes have the potential to respond to human stimuli, even if the wind effects are small. Use terrain to provide a safety margin, such as choosing a slope with a gentle slope.
概要
Avalanche
Yesterday (22nd), a size 1 dry loose snow avalanche was reported in the treeline below. This avalanche was caused by low cohesion snow that fell during the day and occurred in a ski cut. No information has been received at higher elevations due to stormy weather.
Snowpack
Snow from previous stormy weather is settling and advancing sintering. Here, yesterday morning, 10-20 cm of uncohesive new snow fell and was responding to human stimulation. Since yesterday afternoon, the snowfall has turned into a strong snowfall accompanied by winds, which are currently blowing at higher elevations. Snowfall seems to be mainly at higher elevations, and is more common in the northern areas. Today is a day to be cautious and to examine the slab's response to human stimuli.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy, occasionally sunny, with a daytime high of 2 °C (418 m elevation) for northern Nagano Prefecture. At the AMeDAS Hakuba (elevation 703 m), the temperature is -7.8 °C (as of 5:00 a.m.), and 1 cm of snow has fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -18 °C (as of 5:00 a.m.) with northerly winds averaging 15 m/s and a maximum instantaneous wind speed of 20 m/s. At 4:41 a.m. on February 23, the Nagano District Meteorological Observatory forecast 20 cm of snowfall for northern Nagano Prefecture in 24 hours until 6:00 a.m. on February 24.
