Avalanche Bulletin
更新日時: 2024/03/05 05:30
Hakuba
Alpine Low
Treeline Low
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Difficult avalanche conditions. Unlike yesterday, a day when avalanches can easily occur, this day is prone to errors in situational awareness. To the feel of walking, the snowpack may seem to be stabilizing. However, storm snow is not yet fully sintering and the condition of the old snow surface is various, so the triggering sensitivity varies considerably from place to place. In addition, there are persistent slabs lurking to the north that are very difficult to deal with. What you can do to be safe is to be sensitive to avalanche terrain awareness and use low angles simple terrain when skiing. Don't forget to check for "terrain traps" below you. The next stormy weather cycle will begin in the afternoon. Heavy snow is in the forecast, so please plan your tours with that in mind.
Avalanche Problem
ストームスラブ Storm slab
Be vigilant where fresh snow on the surface has more of a slab character.
ウインドスラブ Wind slab
Winds on the main ridge have subsided somewhat from yesterday's midday winds, averaging about 10 m/s west to northwest.
持続型スラブ Persistent slab
Faceting snow that may be problematic has been identified not only at higher elevations, but also in the upper part of the below treeline (around 1,700 m). Persistent slabs are triggered where the snowpack to the weak layer is thin. A hard snow surface does not mean safety.
概要
Avalanche
Numerous size 1-1.5 storm slab avalanches were observed yesterday (4th) at the ski area safety control. Numerous loose snow avalanches were also observed. No reports have been received in the mountain areas due to poor visibility.
Snowpack
The snowfall that began in the afternoon of the 3rd subsided by noon on the 4th, bringing 30-40 cm of new snow in the upper part of the below treeline. As of yesterday morning, this new snow was not well consolidated, causing loose snow avalanches. Later in the afternoon, with the arrival of light sun and warmer temperatures, the new snow is rapidly settling. In the middle layer of the snowpack, the Melt-Freeze layer (formed by rainfall on February 21) and faceted snow remain a concern.
Weather
The Japan Meteorological Agency is forecasting southerly winds, cloudy skies, snow or rain in the evening, and a daytime high of 6 °C for northern Nagano Prefecture. At 703 m elevation (Hakuba), the temperature is -3.9 °C (as of 5:00 pm), and no new snow has fallen in the past 12 hours. The Nagano District Meteorological Observatory forecast 25 cm of snowfall for northern Nagano Prefecture at 4:37 a.m. on March 5 in the 24-hour period ending at 6:00 a.m. on March 6.
