Avalanche Bulletin
更新日時: 2025/03/23 05:30
Hakuba
Alpine Fair
Treeline Fair Depends on the degree of temperature rise and solar radiation
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
As with yesterday, this is a day to be on the lookout for wind slabs in alpine areas and wet loose snow avalanches or glide avalanches below treeline. At lower elevations, one should take into account the continued high temperatures and the large amount of meltwater throughout the night. Avoid slopes with glide cracks, and do not stay under them. Always be mindful of the slope above you when descending the valley line later in the ski tour. Snow blocks left on cliff-like terrain are extremely unstable.
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
Snow blocks remaining on extreme terrain are unstable. Do not stay under slopes with glide cracks.
点発生湿雪雪崩 Wet Loose snow
The rating is as of the morning. At very low elevations, the surface snow is becoming thicker and losing strength. The amount of snow entrained is increasing and becoming more likely to increase in size. Even if you are in the forest, watch out for very steep gully terrain.
概要
Avalanche
Yesterday (22nd), a size 2 wind slab avalanche occurred spontaneously on the north slope of the alpine area. Several size 1 wet loose snow avalanches were also reported below treeline.
Snowpack
Near the main ridge, blast winds have been blowing since yesterday. Due to this effect, some wind slab avalanches were observed yesterday in Alpine. On the other hand, at elevations not affected by the wind, the snow is in spring conditions due to high temperatures and solar radiation. At the base of the mountain (700 m elevation), temperatures have remained above 10°C since yesterday morning at 9:00 am, and the snow is melting.
Weather
The Japan Meteorological Agency is forecasting northerly winds, sunny, occasionally cloudy, with a daytime high of 18 °C (418 m elevation) for northern Nagano Prefecture. At AMeDAS Hakuba (elevation 703 m), the temperature is 12.1 °C (as of 5:00 a.m.), with no precipitation in the past 24 hours. At the main ridge (elevation 2,400 m), -2.3 °C (as of 5:00), with northerly winds averaging 27 m/s and a maximum instantaneous wind speed of 38 m/s.
