Avalanche Bulletin
更新日時: 2022/03/10 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Good 硬いウインドスラブが風下斜面の局所にあります。Isolated pockets of stiff wind slab on lee aspects.
Treeline Good 凍結硬度が上昇するため、濡れた雪の雪崩が起こりうる状況となります。Wet slide activity may be possible as the freezing level rises.
Below Treeline Good 濡れた雪の雪崩の活動は活発になります。Increased possibility of wet slide activity.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Temperatures rise and solar radiation is strong, so don't get under the glide cracks that are often seen at low altitudes. Also, the snow mass that rests on the trees is hard, and it is necessary to be vigilant not only for the danger of falling, but also for those that have already fallen on the snow surface. At low altitudes, the snow surface will become wet and heavy. With warming temperatures and a clear sky avoid anytime spent below glide cracks that can Be found on many steep aspects at lower elevations. Any snow remaining in trees is likely to fall during Thursday creating hazards not only from above but also leaving large chunks of firm snow on the surface. The Snowpack at Lower Elevations is likely to become wet and heavy today.
Avalanche Problem
ウインドスラブ Wind slab
時間経過したウインドスラブがアルパインにはまだ残っています。しかし、このスラブは硬いため、人間一人の刺激で誘発するのは難しいと思われます。本日からの昇温は、このスラブが持つ不安定性の解消に役立つはずです。ただし、注意してほしいのは、凸状の部分などスラブに負荷が掛かっている、すなわち誘発しやすい場所を避けるということです。Isolated pockets of wind slab still remain in the alpine although these slabs appear to be stiff and hard to trigger by a single person load. The current warming trend will continue to settle these slabs throughout Thursday. Caution is still advised around natural trigger points such as convex roles where these slabs will have greater stress and should be avoided.
点発生湿雪雪崩 Wet Loose snow
晴天に恵まれる本日（木曜）の凍結高度は600mを超えるとされており、濡れた雪の活動が活発になりえます。日当たりの良い斜面では、積雪表層の強度が低下した指標として、露出した岩の周囲からの点発生雪崩を確認してください。凍結高度が下がると、それに伴い雪崩の危険性も急速に下がります。With clear sunny skies on Thursday and a freezing level reaching above 600m there is a possibility of wet loose activity in the heat of the day. Be wary of sinking into the snowpack on sunny slopes and look for signs of point release avalanche from rock features as an indicator the snow surface has become weak. The hazard rating will decrease quickly as the freezing level lowers and we have cloud cover in the coming days.
概要
Avalanche
There have been no reports of the new avalanche in the past few days. No new activity has been reported over the previous days.
Snowpack
Previously reported wind slabs are showing calmness and have also increased hardness, so they seem difficult to induce. The biggest concern now is the effects of warming and solar radiation at lower elevations. As the freezing altitude rises, the area of the spring thaw-freezing cycle is also expanding. Previously reported wind slabs appear to be settling and becoming stiff and hard to trigger, our main focus now turns to the effect that warmer temperatures will have on the Snowpack at Lower Elevations. Recent observations suggest we are starting to enter a spring melt-freeze cycle as the Freezing level climbs up the mountains.
Weather
Since it is covered by high pressure, the wind from the south is also weak, and it is forecast that the temperature will rise today (Thursday) and the weather will be good. This good weather is also likely to be a short period of time due to the passage of low pressure on Friday evening. The freezing altitude is also forecast not to be lower than 300 m after this. We expect low wind speeds from the south and a warm sunny Thursday as we remain under a Dominant high-pressure system. The Sunny Skies will be short-lived as we expect a low to pass over in the evening Bringing some precip on Friday. The freezing level is not expected to drop below 300m in the coming week.
