Avalanche Bulletin
更新日時: 2022/01/01 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair 本日、継続する降雪と明日の天候は新雪を落ち着かせる可能性がありますが、月曜日には再び、荒天の予報が出ており、これは雪崩の危険を押し上げます。Leeward slopes will continue to load through the day today before calmer weather prevails on Sunday allowing the new snow a chance to bond. A second storm system will increase the risk of slab avalanches on Monday.
Treeline Good 新雪の下に危険なスラブが隠れている可能性があります。表層の雪で誘発された雪崩によって、この層までステップダウンすると規模の大きなものとなりえます。Look for indications of a cohesive slab buried below the new snow. If an avalanche steps down to this layer the consequences will be greater.
Below Treeline Good 昨日、ストームスラブが人の刺激で反応しています。今日は、すべての地形で特別な注意が必要です。Storm slabs were reactive yesterday. Use extra caution on all terrain today.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Approach open slopes where large avalanches can occur very carefully, and avoid slopes where snow cover does not support the terrain. Buried weak layers are difficult to find, and the situation may be better than yesterday, but if triggered, it will have a significant impact on the size of the avalanche. The next avalanche information will be announced on Tuesday, but the forecast for stormy weather is coming out on Monday. If there is a heavy snowfall or strong wind, please judge carefully. Use caution approaching open terrain where large avalanches are possible and avoid skiing on unsupported slopes. The buried weak layer may be difficult to spot and more stubborn than it was yesterday However the consequences will be greater today. Another significant storm is expected Monday before the next forecast is due to be released on Tuesday. Evaluate conditions carefully if this storm brings heavy snow and strong winds as forecasted.
Avalanche Problem
点発生乾雪雪崩 Dry Loose snow
とても急な斜面では乾雪の点発生雪崩が発生しえます。下方に「地形の罠」がある斜面に警戒してください。Loose dry avalanches can be expected on steep slopes. Use caution skiing above terrain traps.
ストームスラブ Storm slab
昨日はストームスラブが人的な刺激に反応しています。この24時間で状況は多少改善している可能性はありますが、スラブの強度が上がっているため、もし、誘発するとより大きなものが発生しうる状況です。Storm slabs were reactive yesterday. While bonding may have improved in the past 24 hours, the potential avalanche size is larger today as a result of the added load.
ウインドスラブ Wind slab
継続した風によって再配分された雪により、風下側にはウインドスラブが形成しています。Rapid loading and steady wind transport has caused wind slab to form on leeward slopes.
概要
Avalanche
An avalanche of a size 1 storm slab on the southeastern slope of Mt. Shiribetsudake, at an altitude of 900m, was reported on December 31. Triggering is accidental, there are no injuries, etc. Size 1 skier accidental Storm slab down 30cms @900m SE aspect Shiribetsu reported on Dec. 31 (no Injures) Size 1 skier accidental Storm slab down 20cms Nitonupurri West Aspect on Dec. 31 elevation not specified) (no injures) Size 1 skier accidental Wind Slab down 30cms @900m SE aspect of Misunosawa (no injuries)
Snowpack
There was 10-30 cm snowfall on the south side (Niseko, Yotei, Shiribetsu) in the avalanche announcement area, but it was considerably less in the north (Yoichi). This fresh snow rests on the 20-30 cm stormy snow that reacted with the above induced avalanches. Also, the lower layer has snow from the previous stormy weather with a thickness of about 1 m, which has progressed in spherical shape. In addition, the lower layer is a raincrust with a thickness of about 30 cm. The southern part of the region (Niseko, Yotei, shiribetsu) received 10-30cms of overnight snowfall while the northern part of the region (Yoichi) received considerably less. The new snow sits on a 20-30cm layer of storm snow that was reactive yesterday as noted in the avalanche observations above. Below this layer is ~1m of rounding and consolidating snow. At the bottom of the pack is a 30cm thick refrozen rain crust.
Weather
Northwesterly winds will continue today, with weak snowfall and low temperatures forecast from Saturday night until it is covered by high pressure. The next low pressure is approaching on Sunday night, and it is forecast to become heavy snow again on Monday. The NW Flow will continue today bringing light precipitation and cold temperatures before A high pressure starts pushing into the region Saturday night. This will bring milder temperatures, light winds and no snow on Sunday until a new low Pressure system establishes on Sunday night. Heavy snowfall and cold temperatures are expected again on Monday.
