Avalanche Bulletin
更新日時: 2025/03/20 06:30
Myoko
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
This is a day to be alert for unstable slabs that remain in certain terrains. Do not jump into large slopes out of the blue, but start the day on smaller slopes. Observe your surroundings carefully, look for traces of yesterday's wind and spot wind slab formations. Whatever type of instability is present, choosing a slope with a gentle slope is the most effective means of avalanche protection. Inexperienced persons should look for simple terrain with no "terrain traps" below the slope. For the more experienced, remember that a day that you skied one slope and had no problems is a day that does not guarantee safety on another slope. Always observe the slope with fresh eyes and consider if there are any elements that could increase instability. Snow is a good cold condition. If the slopes are not affected by solar radiation, you will enjoy great fresh snow. Have a good day.
Avalanche Problem
ウインドスラブ Wind slab
Be alert for wind slabs formed by yesterday's strong winds. Even if the surface layer has hardened over time, that does not mean it is safe. Underneath that slab may be hidden snow that has not yet gained sufficient strength. Be especially wary of terrain that is convex or unsupported, or the sides of a branch ridge.
ストームスラブ Storm slab
Watch out for unstable slabs that remain on steep slopes unaffected by yesterday's strong winds.
概要
Avalanche
A number of size 1 wind slab avalanches were observed yesterday (19th) in the below treeline. All were human-triggered due to ski cuts and other factors. Shooting cracks over 10 m were also reported. No information has been received at higher elevations.
Snowpack
The depth of the new snowfall, brought about by two low-pressure transits in the last four days and the short, strong winter pressure pattern that followed, is about 60 cm below treeline. And very strong westerly winds blew continuously throughout the day yesterday. Currently, there are two concerns about snow accumulation. One is the improvement in the strength of the weak layer yesterday, which was sensitive to human stimulation, and the second is the condition of the wind slab formed by yesterday's strong winds.
Weather
The Japan Meteorological Agency is forecasting westerly winds, later, southerly winds, cloudy, sunny before noon, and a daytime high of 11 °C (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature is -8 °C (as of 4:45 a.m.) and 5 cm of snow has fallen in the past 12 hours.
