山麓-6度降雪40cm除雪困難 モイワ800m-10.6度北西9.2m雪庇ふきだまり発達 アンヌプリ1100m-12.8度西北西6.5m ビレッジ1000m-11.6度西2.9m ひらふ花園1000m-12.3度東南東5.4m 花園800m-4.8度北北東3.4m 日本海弁慶岬北西18m 神威岬北西13m気圧1001hPa波高3.9m、
風のピークは午前2時から3時、北西22mで波高上昇4m前後、観測から雪庇とふきだまりの成長は著しく更に発達中。標高800m以上の雪崩リスクはきわめて高く、雪庇斜面や谷の側壁、ノールから破断面厚さ50-80cmの面発生表層雪崩が起こる可能性がある。ふきだまり(風成雪スラブ)の成長速度に圧密が追い付かず、少しの刺激で深部から破断しやすい。雪崩の発生面は昨日の暖気層だがそこが凍るから雪崩が起こるのではない。急激に重さを増したスラブの内部崩壊(弱線破断)が雪崩の理由となる。樹林帯内の急斜面も危険、ラッセルが腰を越えれば雪崩に用心したほうが良い。リフトが回っても今日はゲレンデから出ないほうが良い。雪は狂喜乱舞の深雪。転倒衝突に注意。ビーコンは持っているか? 今日は飾りではない。良い一日を。こんな日もある。ゲート開閉は未定。
Mountain base -6℃, 40cm snowfall, hardcore snowclearing. Moiwa 800m: -10.6℃, NW9.2m/s, cornice ans snowdrifts developments. Annupuri 1100m: -12.8℃, WNW6.5m/s. Niseko Village 1000m: -11.6℃, W2.0m/s. Hirafu Hanazono 1000m: -12.3℃, ESE5.4m/s. Hanazono 800m: -4.8℃, NNE3.4m/s. Sea of Japan Benkei cape NW18m/s, Kamui cape NW13m/s, 1001hPa, 3.9m waves.
The wind peaked between 2:00am and 3:00am at NW 22m/s with wave heights rising around 4m. Morning observations show that cornices and snowdrifts have grown significantly and are still developing. Above 800m, the avalanche risk is extremely high. There is a potential for slab avalanches with a fracture line depth of 50–80cm on cornice slopes, valley sidewalls, and knolls. The speed of wind-slab growth has outpaced any compaction, making it prone to deep-layer fracturing from even the slightest trigger. The sliding surface would be yesterday’s warm layer, but it’s not that the avalanche occurs because that layer is freezing. The rcause for the slide is the internal collapse (shear failure within the new snowpack) of the slab, which has rapidly and drastically gained weight. Steep slopes below tree-line are also dangerous. If the trail-breaking exceeds waist-deep, you should be on high alert for avalanches. Even if the lifts are running, it is better not to leave the groomed runs today. The snow is “madly deep”. Watch out for falls and collisions. Do you have your beacon? Today, it is not an ornament. Have a good day. Gate opening is TBD.
出典 Source：気象庁 JMA website (www.jma.go.jp/bosai/weather_map/)