山麓-5度風弱く降雪10cm モイワ800m-7.5度東0.7m吹きだまり発達終息降雪10cm アンヌプリ1100m-9.7度南西1.2m ビレッジ1000m-8.2度南0.8m ヒラフ花園1000m-9.2度北2.0m 花園800m-6.5度北2.1m 日本海弁慶岬北西9m 神威岬西南西7m気圧1018hPa波高不明、
等圧線幅ひろく海上、山ともにおだやか、寒気流入。観測と各データの評価、パトロール報告からコース外の雪崩リスクは下がっているが引き続き全層雪崩の危険は高い。全層雪崩は稜線風下側に堆積した厚いふきだまりの融解だけではなく、寒気流入にる収縮でも起こる。コース外の調査を優先するため各山頂ゲートは閉じられる。雪崩には多くの種類がある。5日に起きたような湿雪性の表層雪崩や今日起きるはずの乾いた浅い表層雪崩、そして全層雪崩や氷河雪崩では発生のかたち、速度や規模が全て異なる。条件がそろえば雪崩は起こり、そこに人がいれば事故になる。
現在国の防災科学研究所が従来の弱層理論とは異なるアプローチでの雪崩発生メカニズムの研究に取り組んでいる。吹雪の中、山に泊まり込んで実験を続ける研究者に敬意を表する。研究は10年近く行われておりニセコはそれに協力している。事故防止に役立つ研究成果が生まれることを願っている。
Mountain base: -5°C, light wind, 10cm new snow. Moiwa 800m: -7.5°C, E 0.7m/s, development of snowdrifts has ceased, 10cm new snow. Annupuri 1100m: -9.7°C, SW 1.2m/s. Niseko Village 1000m: -8.2°C, S 0.8m/s. Hirafu Hanazono 1000m: -9.2°C, N 2.0m/s. Hanazono 800m: -6.5°C, N 2.1m/s. Sea of Japan Benkei Cape: NW 9m/s. Cape Kamui: WSW 7m/s, pressure 1018hPa, wave height unknown.
The pressure gradient is wide, the weather is calm both at sea and in the mountains and cold air is flowing in. Based on observations, data evaluation, and patrol reports, the general risk of avalanches outside the ski resort boundaries has decreased; however, the danger of full-depth (glide) avalanches remains high. Full-depth avalanches are triggered not only by the melting of thick snowdrifts deposited on the leeward side of ridges but also by contraction caused by the inflow of cold air. All peak gates will remain closed to prioritize out-of-bounds inspections. There are many types of avalanches. The wet surface avalanche that occurred on the 5th, the dry shallow surface avalanche expected today, full-depth glide avalanches, and glacier avalanches all differ in their formation, speed, and scale. When conditions align, avalanches occur, and if people are present, it becomes an accident.
Currently, the National Research Institute for Earth Science and Disaster Resilience (NIED) is researching avalanche trigger mechanisms using an approach different from the traditional “weak layer theory.” We respect the researchers who stay overnight in the mountains during blizzards to continue their experiments. This research has been ongoing for nearly ten years, and Niseko continues to cooperate with these efforts. We hope for research results that will contribute to accident prevention.
出典 Source：気象庁 JMA website (www.jma.go.jp/bosai/weather_map/)