Avalanche Bulletin
更新日時: 2025/02/18 06:30
Myoko
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Very dangerous avalanche conditions. Even if you are in the forest, pay maximum attention to the start zones where wind-driven snow has accumulated. This is a day for using terrain with a large safety margin and conservative decision-making. Even a size 1 avalanche can be deadly if swept through the forest, striking trees. For inexperienced skiers, powder ridings in the ski resorts are recommended. When skiing in powder snow areas, use the buddy system with a companion.
Avalanche Problem
ストームスラブ Storm slab
Temperatures are dropping with the inflow of cold air. The instability that was clearly observed yesterday continues today, and the increased snow cover should be considered a potential situation for large avalanches.
概要
Avalanche
Many size 1 storm slabs were observed yesterday (17th) below treeline. The bed surfaces are Melt-Freeze crusts of old snow. Shooting cracks of 5-10 m were also reported. At very low elevations, wet loose avalanches were occurring in ski cuts, due in part to the morning rainfall. On the other hand, no information has been received at the higher elevations due to stormy weather.
Snowpack
Snowfall began yesterday morning (17th). Due to a small low pressure system passing through Niigata Prefecture, there was no wind and the snowfall was caused by high temperatures. Later, when the low pressure system passed to the east, it turned into a snow storm. Below treeline, 20-30 cm of snow fell during the day, resulting in easy avalanches on ski cuts.
Weather
The Japan Meteorological Agency is forecasting winds out of the west, slightly stronger, snow, and a daytime high of 3 °C (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature was -11 °C (as of 5:45 a.m.), with 18 cm of snow having fallen in the past 12 hours and 61 cm in the past 24 hours. The Niigata District Meteorological Office forecast 70 cm of snowfall for the mountains of Joetsu at 5:42 a.m. on February 18 in the 24-hour period ending at 6:00 a.m. on February 19.
