Avalanche Bulletin
更新日時: 2024/03/10 05:30
Hakuba
Alpine Fair
Treeline Fair
Below Treeline Fair
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
Dangerous avalanche conditions. Even when the weather improves, the snow will not stabilize quickly. Even below treeline, large avalanches are possible on large open slopes. Be especially vigilant around the Goryu Toomi-One and Happo-One. Even if there are trees around you, consider whether there is a large start zone above you. The presence of trees does not necessarily mean safety. Also, the snow is so deep that even if you are in the forests, be aware of small depressions and other potential "terrain traps." Even a size 1 avalanche can easily bury a person and have serious consequences. Inexperienced groups are encouraged to enjoy fresh snow on the ski slopes.
Avalanche Problem
ストームスラブ Storm slab
This is just after a heavy snowfall. The snowpack is still unstable, and safe terrain selection is necessary. Yesterday's report from the ski patrol at the ski resort reported more instability on the northern slopes.
ウインドスラブ Wind slab
Very strong northwest or west winds are redistributing the snow. Be very alert not only to open slopes, but also to wind slabs that are forming on terrain pockets, such as on the sides of branch ridges.
持続型スラブ Persistent slab
Since a large amount of snowfall has been placed, the instability of the persistent slab is considered to be increasing.
概要
Avalanche
Yesterday (9th), numerous avalanches (size 1-2) were reported at morning ski resort management. Some ski areas were closed due to hazardous conditions. Due to the stormy weather, avalanche data in the mountain areas is minimal, but several size 1 storm slab avalanches were reported in the below treeline.
Snowpack
The snowfall that continued until yesterday morning temporarily weakened before noon, but began again yesterday afternoon when a winter pressure pattern formed. Snowfall amounts during this storm varied throughout the Hakuba Valley, ranging from 40 to 80 cm below treeline. Wind speeds were very high at higher elevations, averaging 20 m/s, before noon yesterday. Instability caused by the combination of the Melt-Freeze layer in the middle of the snowpack (formed by rainfall on February 21) and faceted snow remains a concern.
Weather
The Japan Meteorological Agency is forecasting northerly winds, snow, cloudy before noon, sunny later, and a daytime high of 4 °C for northern Nagano Prefecture. At 703 m elevation (Hakuba), the temperature is -3.4 °C (as of 5:00 a.m.), and 9 cm of snow has fallen in the past 12 hours.
