Avalanche Bulletin
更新日時: 2024/03/14 06:00
Myoko
Alpine Low
Treeline Low
Below Treeline Fair Watch for rising temperatures during the day
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Be alert for wind slabs that were active yesterday. Observe the snow surface for evidence of strong winds or if the upper snowpack has a tendency to slab. Assuming that the instability of storm weather has not yet been resolved, choose slopes with a high degree of safety. The risk can be greatly reduced by choosing slopes that are low angles, and by choosing smaller slopes that support the snowpack rather than larger terrains. It is very important to act on principle, skiing one person at a time and watching your fellow skiers in a safe place. The weather forecast is predicting southerly winds and a large temperature increase. Keep an eye out for snow changes during the day. Have a good day.
Avalanche Problem
ウインドスラブ Wind slab
At higher elevations, westerly winds are still averaging 10 m/s or more.
ストームスラブ Storm slab
Terrain selection should be based on the assumption that the instability of storm weather has not yet been resolved.
全層雪崩 Glide slab
Danger of glide avalanche at very low elevations. Stay away from slopes with glide cracks.
持続型スラブ Persistent slab
The danger of persistent slabs from ice layer or Melt-Freeze crusts formed by the February 21 rainfall and faceted snow that formed on top of them has not yet been completely eliminated.
概要
Avalanche
Yesterday (13th), several size 2 wind slabs were observed at the ski area safety control. Extremely long (100 m) shooting cracks were also reported. A size 2 glide avalanche was observed. On the other hand, no avalanche activities has been received for the mountain area due to poor weather conditions.
Snowpack
On the 12th, a low pressure system passed through the area and shifted to a winter pressure pattern. In the early morning of yesterday (13th), the intensified pressure system brought about 30-40 cm of snowfall accompanied by extremely strong winds. As a result, many areas with an "upside-down structure," where high-density snow was placed on top of relatively low-density snow, appeared, causing many avalanches. In addition, high temperatures and rainfall at very low elevations caused glide avalanches.
Weather
The Japan Meteorological Agency is forecasting winds from the south, then slightly stronger winds from the west, with a daytime high of 13 °C (13 m elevation) for the Joetsu region of Niigata Prefecture. At Sasagamine, Myoko (elevation 1,310 m), the temperature is -4 °C (as of 4:45 a.m.), with no new snowfall in the past 12 hours.
