Avalanche Bulletin
更新日時: 2025/03/22 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair Danger increases with the degree of temperature rise and solar radiation
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Even a thin slab (e.g., 15 cm) in thickness can easily be size 2 if the terrain is large and forms a wind slab with a large spatial scale. Today is such a day. If you watch blowing snow, extreme caution should be exercised on large terrain extending below the main ridge line. On the other hand, at lower elevations, significant temperature increases over yesterday are forecast. Watch closely as snow that is crusting in the morning melts and loses strength. If you choose the right slope at the right time, you will have a good run. Have a good day.
Avalanche Problem
ウインドスラブ Wind slab
Extremely strong winds are blowing continuously. Be on the lookout for wind slabs, especially in the alpine elevation zones. In addition, the hard snow surface itself is undergoing ablation in areas where it is being pounded by the wind.
全層雪崩 Glide slab
Positive temperatures continue at the base of the mountains. Snow blocks remaining on extreme terrain have become unstable. Do not stay under slopes with glide cracks.
点発生湿雪雪崩 Wet Loose snow
Assessment as of morning. Elevated temperature and solar radiation during the day increased the likelihood of induction.
概要
Avalanche
Yesterday (21st), a size 1 wet loose snow avalanche was reported below treeline.
Snowpack
At the treeline and below treeline, storm snow is undergoing settling. On all but the most northerly slopes, where there is no influence of the sun, crusts are forming on the snow surface, the thickness of which depends on the degree of solar radiation and temperature. In Alpine, extremely strong north to westerly winds have been blowing from yesterday morning to the present. Those seeking higher elevations will need to watch for wind-driven snow. At 15:00 yesterday, 10.7 °C was recorded at the foot of the mountain (703 m). A higher temperature rise is forecast for today, which will result in more snow melting.
Weather
The Japan Meteorological Agency is forecasting a southerly wind, clear skies, and a daytime high of 19 °C (418 m elevation) for northern Nagano Prefecture. At AMeDAS Hakuba (elevation 703 m), the temperature is 1.8 °C (as of 5:00 a.m.), with no precipitation in the past 24 hours. At the main ridge (elevation 2,400 m), -3.5 °C (as of 5:00) with northerly winds averaging 20 m/s and a maximum instantaneous wind speed of 28 m/s.
