Avalanche Bulletin
更新日時: 2022/02/03 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Good アルパインではスラブが形成しており、南向きの斜面で反応しています。Slabs have formed in the Alpine and have been reactive on Southerly aspects.
Treeline Good 過去数日の降雪により、急峻な地形では点発生乾雪雪崩がありえます。Increased snowfall over the last few days will result in loose dry activity in steep terrain.
Below Treeline Good 小さい点発生雪崩であっても、「地形の罠」があると重大な結末となります。たとえば、足元をすくわれ、崖から落ちるなどです。Be wary of terrain traps as small low volume loose dry activity may have high consequences if you are knocked from your feet.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
In the future, in order to deal with multiple “avalanches to keep in mind”, deeper terrain recognition will be required. Areas that are easy to induce, such as convex terrain, should be avoided on high-elevation, southerly slopes. On the north side, there can be point avalanches that are human-induced in steep terrain. Glide cracks are difficult to see from the top of the slope, and at low elevations, the cracks are expanding. Complex terrain decisions will be needed over the coming days as we deal with a mix of Avalanche problems. Southerly aspects at higher elevations are our main concerns, identifying and avoiding clear stress points such as convex rolls will be needed. On Northerly Aspects we expect loose dry activity to be triggered by a single person in steep terrain. Glide cracks will be hard to see from above and are widespread at lower elevations.
Avalanche Problem
点発生乾雪雪崩 Dry Loose snow
過去24時間で20-40 cmの新雪がありましたので、急峻な地形では点発生乾雪表層雪崩がありえます。With another 20cm - 40cm of new snow over the last 24 hours, Loose-dry activity will occur in steep angled terrain.
ウインドスラブ Wind slab
過去数日間、降雪は中程度の西風を伴っています。このため、アルパインではウインドスラブが形成され、人間一人の負荷で誘発しうる状態です。南斜面においては、埋没した融解凍結クラストと上載積雪との境界面における結合具合に懸念が残っています。これはこの数日の降雪で、その境界面にさらなる負荷が掛かっているからです。Moderate winds from the West have continued as has the snowfall during the previous few days. With plenty of new snow to transport slabs have formed and have been reactive in single person loads in the Alpine. The Southerly aspects remain a growing concern as greater loads are deposited onto buried crusts and the bond appears to be weak.
概要
Avalanche
We have received reports that there have been multiple surface avalanches in the area north of the avalanche announcement area, where the ocean is close and the influence of the wind is stronger. These are occurrences in convex areas located in steep terrain. We have received reports of multiple slabs failing in the North of the Range as stronger winds along the coast have transported snow onto the lee. These avalanches occurred in steep angled terrain and on knolls.
Snowpack
It seems that the combined state of fresh snow and old snow is not good on the south-facing slope. In particular, at high altitudes, new slabs are reacting to loads. Elsewhere, point-generated dry snow avalanche activity has been observed over a wide range. Our concern is to what extent the snow and old snow surface of the most recent stormy weather have increased the coupling, and at the same time whether the lower snow layer remains stable. It appears the bond may be weak between the new and old snow across Southerly aspects. Fresh slab formation especially at higher elevations appears to be reactive in obvious stress points. Elsewhere loose dry activity due to the volume of new snow is widespread. Our concerns remain in the latest storm snow and how it has bonded to the old snow surface as the lower pack remains stable.
Weather
Due to the effects of the northern low, there is continuous snowfall throughout the week, and weak to moderate westerly winds are forecast. We are expecting constant snowfall throughout the week and low to moderate Westerly winds as we are fed by a low pressure system to the North.
