Avalanche Bulletin
更新日時: 2024/03/07 06:00
Myoko
Alpine Low
Treeline Low
Below Treeline Fair Note the avalanche of wet snow due to elevated daytime temperatures
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Be alert for wind slabs at higher elevations. The instability of stormy weather has not yet been resolved, so watch out for storm slabs in isolated terrains and other areas where the snow surface layer has strong slab characteristics. As temperatures have dropped, dry snow can be enjoyed on the north-side slopes that are not affected by the wind. At the same time, however, terrain selection is key, as there are still areas on the north side where the snowpack is unstable. Avoid slopes where the terrain is not shaped to support snowpack, and look for simple areas with lower angles slopes. Also, be sure to check for "terrain traps" below that slope. When filming your fellow riding, choose a safe location off the avalanche terrain.
Avalanche Problem
ウインドスラブ Wind slab
The wind was light on the main ridge until yesterday afternoon. Since then, winds have been increasing from the northwest. As you move along, look for wind trails and notice the formation of wind slabs.
ストームスラブ Storm slab
Temperatures are dropping at higher elevations along with the winds that picked up yesterday afternoon. It is necessary to travel on the assumption that stormy weather instability remains in the north, where it can still be triggered.
持続型スラブ Persistent slab
It has been observed that near the treeline, the temperature gradient has already dissipated. However, various tests have shown some cautionary results.
概要
Avalanche
Yesterday (6th), size 1 slab avalanches were reported in extreme terrain features below treeline. Also, due to elevated temperatures during the day, many size 1 loose snow avalanches were reported at lower elevations.
Snowpack
In the upper part of the below treeline, there is a recent 30-40 cm of new snow that is settling. The new snow was deposited under the weak influence of the wind, but since yesterday afternoon, the wind has begun to increase. Today, we need to watch for the formation of wind slabs at higher elevations. In addition, a persistent weak layer has formed in the middle of the snowpack on some of the northern slopes of the treeline and alpine, and remains a concern.
Weather
Today, high pressure is expected to prevail, but cold air is expected to influence the region. The Japan Meteorological Agency is forecasting northerly winds, cloudy skies, and a daytime high of 6 °C (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature is -6 °C (as of 4:45 a.m.), and 1 cm of snow has fallen in the past 12 hours.
