Avalanche Bulletin
更新日時: 2021/12/30 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair 本日（木曜）の降雪が、明日（金曜）の面発生雪崩の危険を押し上げます。Added snowfall Thursday night will increase the risk of slab avalanches on Friday.
Treeline Good 夜間にあった降雪で隠れているスラブに注意する必要があります。Look for stiffer slabs buried just below the surface of the overnight snow.
Below Treeline Good 「地形の罠」の上部にある急斜面に気をつけるなど、一般的な注意事項を考えてください。Normal caution is advised particularly on steep slopes and above terrain traps.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Storm slabs may be buried just below last night's snowfall. Carefully spot it before entering an open slope where larger avalanches can occur. It is forecast that the temperature will drop significantly on Friday and the cold will become severe, so don't forget to take measures against the cold. Storm slab may be buried just beneath the surface of the overnight. Investigate carefully before stepping onto bigger slopes in open terrain where the likelihood of a larger more destructive avalanche is increased. Be prepared for the dropping temperatures and very cold weather by the end of Friday.
Avalanche Problem
ウインドスラブ Wind slab
昨日の南西の風によって、普段はあまり観察されることのない、北側の地形局所にウインドスラブが形成していることを考慮する必要があります。Yesterday`s SW wind may have created pockets of windslab on North aspects where they are less commonly observed.
ストームスラブ Storm slab
昨日は昇温しましたので、以前の好天の雪は焼結を進めていると考えられます。Yesterday`s warmer temperatures may have caused the storm snow to consolidate into a more cohesive slab.
概要
Avalanche
No new avalanches have been reported. No new avalanches have been reported
Snowpack
By this morning there was a snowfall of 5-10 cm. This fresh snow rests on stormy snow with a thickness of 120 cm or more. Snow in stormy weather is sintering, and below it there is a crust due to rainfall of about 30 cm. In the snow in stormy weather, there is no noticeable weak layer, and it also combines well with the crusts of the bottom of the snow cover. 5-10cms of fresh snow fell overnight. This sits on ~120cms of consolidating and rounding storm snow. Below this snow is a 30cm thick rain crust at the bottom of the snowpack. There are no notable weak layers within the storm snow and it is well bonded to the crust at the bottom of the pack.
Weather
The temperature rose temporarily yesterday, but northwest winds have entered, and the temperature is dropping again. It is forecast that the temperature will drop sharply by tomorrow, and it will be near -20° C at high altitudes. Today (Thursday), there will be some snowfall and a weak northwesterly wind, followed by a consolidated snowfall at night, and it is forecast to subside somewhat on Friday. After a brief temperature spike yesterday, the NW flow has resumed bringing back cooler Temperatures. Temperatures will drop steadily through the day today, overnight and into tomorrow approaching -20C at upper elevations by the end of Friday. Light to moderate NW winds are expected throughout this time with light snowfall Thursday. Heavier snowfall is expected Thursday night tapering off on Friday.
