Avalanche Bulletin
更新日時: 2025/02/06 06:30
Myoko
Alpine Fair
Treeline Fair
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
These are very dangerous avalanche conditions. Even if the snowfall weakens temporarily, the instability in the massive snowfall will not be resolved anytime soon. Also, be on maximum alert for wind slabs that have formed due to winds that have been particularly strong since yesterday. Even if you are in the forest, be aware of the avalanche tracks and start zones above you in the forest. For less experienced groups, this is a good day to enjoy fresh snow in the ski area. When doing so, buddy up with a fellow skier and observe the runnable areas. It is not only for your safety but also for the safety of other guests.
Avalanche Problem
ウインドスラブ Wind slab
A 20 m/s westerly wind is blowing at around 2,000 m elevation, violently moving snow to the leeward side. This strong wind moves through the terrain and around the slopes, forming wind slabs at various locations. Underneath the slabs is soft snow from the stormy weather, which is structurally unstable and reacts easily to the stimulus.
ストームスラブ Storm slab
Snowfall is repeatedly strong and weak, and there is a weak layer within the fresh snow that causes it. In steep terrain, it is easy to see how they can be easily triggered by human irritation. Also, because fresh snow is deep and soft, even a small avalanche can be fatal if swept into a small terrain depression, resulting in a deep burial. Maximum attention to terrain is required.
概要
Avalanche
Yesterday (5th) there were multiple avalanches of size 2-2.5 that appeared to have occurred within the past 12 hours. Multiple avalanches, whumpfing sounds, and shooting cracks were also reported at the ski resort's morning safety control. Due to the stormy weather, there were only a few avalanche bulletins in the backcountry, but there were reports of size 1-1.5 avalanches and shooting cracks.
Snowpack
Snowfall began yesterday (4th) with 100-120 cm in the northern part of Myoko. Due to this massive snowfall, avalanches have been reported at vulnerabilities within the new snow. Uncertainty remains high due to the lack of sufficient observational information on the boundary surface between this storm snow and the old snow.
Weather
The Japan Meteorological Agency is forecasting winds out of the west, slightly stronger, snow, and a daytime high of 2 °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 38 cm of snow having fallen in the past 12 hours and 51 cm in the past 24 hours. At 6:02 a.m. on February 6, the Niigata District Meteorological Office is forecasting 80 cm of snowfall along the mountains of the Joetsu Region in the 24-hour period ending at 6:00 a.m. on February 7.
