Avalanche Bulletin
更新日時: 2025/02/19 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Very dangerous avalanche conditions. Even below treeline, consider that large avalanches can occur on open south-facing slopes. Avoid large, steep slopes and choose well-selected avalanche-free slopes, such as gentle slopes and ridges. Adequate safety margins require careful terrain selection and conservative decision-making. When visibility is poor, it is difficult to notice large avalanche start zones above you. Be sure to communicate with your companions. If you are inexperienced, skiing in the ski resorts is recommended. At ski resorts, please ski on open runs. Yesterday, there was a fatal avalanche accident in a closed area of a ski resort in the Tohoku region.
Avalanche Problem
ウインドスラブ Wind slab
Strong northerly winds have moved the snow violently and slabs are forming.
ストームスラブ Storm slab
Yesterday, snowfall weakened temporarily during the day, but intensified again in the evening.
概要
Avalanche
Yesterday (18th), a size 1.5 storm slab avalanche was observed on the southeast slope of the below treeline. This avalanche is a natural occurrence. No information has been received at higher elevations due to stormy weather.
Snowpack
Thin Melt-Freeze crusts and storm snow conditions south of the below treeline were observed to be improving yesterday. However, a tenperature gradient was reported, so caution is still needed regarding the intensity of that boundary. In addition, the stormy snowfall proceeded with settling yesterday due in part to the weak sunlight at lower elevations during the day. Here is the snow (20-30 cm) up to this morning. Continuous and extremely strong northerly winds have been blowing from yesterday to this morning, and wind slabs have formed in diverse locations below treeline.
Weather
The Japan Meteorological Agency is forecasting northerly winds, cloudy, with occasional snow, and a daytime high of 1 °C (418 m elevation) for northern Nagano Prefecture. At Amedas Hakuba (elevation 703 m), the temperature is -6.4 °C (as of 5:00 a.m.), and 10 cm of snow has fallen in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -20°C (as of 5:00), with northerly winds averaging 20 m/s, and a maximum of nearly 30 m/s at the moment. At 4:23 a.m. on February 19, the Nagano Prefectural Meteorological Office forecast 30 cm of snowfall for northern Nagano Prefecture in the 24-hour period ending at 6:00 a.m. on February 20.
