Avalanche Bulletin
更新日時: 2025/01/17 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair Steep slope on south face, uncertainty on boundary surface between new and old snow.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Although the overall avalanche danger level is decreasing, we still need to be very vigilant. Of particular note are the steep slopes that open to the south, even at lower elevations, where there is potential for large avalanches to occur. This is because the Melt-Freeze crust, which provides a good bed surface, is buried, and on top of it there is a thick accumulation of snow that has been moved by strong northerly winds. The large open slopes on the south side of Toomi One and Happo One should be considered very risky. This is a day for careful terrain assessment and conservative route setting. For inexperienced skiers, we recommend skiing within the ski area today.
Avalanche Problem
ウインドスラブ Wind slab
Winds are stronger than yesterday on the main ridge, with average wind speeds of 20 m/s and maximum instantaneous wind speeds of 30 m/s observed since early today.
ストームスラブ Storm slab
Stabilization has been slow due to continued low temperatures. On the lower elevation, south-facing slopes, yesterday's clear skies have settled the surface layer of the snowpack. However, uncertainty remains on very steep slopes regarding the boundary between the Melt-Freeze layer and the snow from the recent stormy weather. A follow-up survey will be conducted.
概要
Avalanche
Yesterday (16th), as visibility opened up in the early afternoon, several size 2-3 avalanches were observed in the alpine to treeline areas. The direction was east to south.
Snowpack
The heavy snowfall that began in the afternoon of January 14 or early morning of January 15 ended yesterday morning (January 16). This stormy weather brought about 1 m of snow hight below treeline. This snowfall was on the steep southern slopes in Melt-Freeze crusts and on the northern slopes in old snow that is slowly sintering. In addition, northerly winds picked up on the afternoon of the 15th, and the snow shifted violently at higher elevations. Yesterday afternoon was sunny, but once again, a wintry pressure pattern prevailed, and in the region's northern below treeline, about 15 cm of snow had fallen by this morning.
Weather
Today, a low pressure pattern is expected to temporarily intensify in the west, but gradually loosen in the afternoon. The Japan Meteorological Agency is forecasting northerly winds, cloudy, then sunny, with snow until dawn, and a daytime high of 1 °C (418 m elevation) for northern Nagano Prefecture. At 703 m elevation Hakuba, the temperature is -3.6 °C (as of 5:00 a.m.), and the snow depth has increased by 3 cm in the past 12 hours.
