Avalanche Bulletin
更新日時: 2025/02/17 05:30
Hakuba
Alpine Fair Rating is as of morning. Danger increases with future snowfall.
Treeline Good Rating is as of morning. Danger increases with future snowfall.
Below Treeline Good Rating is as of morning. Danger increases with future snowfall.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
JAN's avalanche bulletin is not a "forecast" but a "current situation" that is evaluated based on the data available at this time. As alerted in the weather forecast, the avalanche danger level will increase depending on the extent of snowfall starting around noon. The old snow surface is variable, so the bonding of new snow with old snow can be different. The weather is clearly deteriorating today and will continue to do so. If something goes wrong, you need to have a plan to get to the base of the mountain safely with your companions. The snow surface below treeline will be difficult to ski, so inexperienced skiers may find it more enjoyable to ski in the ski resort.
Avalanche Problem
ウインドスラブ Wind slab
Unstable slab remaining in extreme terrain shape
概要
Avalanche
Yesterday (16th), a size 2 glide avalanche and numerous snowballs were observed below treeline. A size 2 wind slab avalanche was also reported in the extreme terrain of the treeline.
Snowpack
Sunny skies and high temperatures over the past two days have brought spring conditions below treeline. With the exception of the northern slopes, the snow surface was moist or wet, which froze hard due to the cooler temperatures until this morning. The strong solar radiation also affected the southern slopes of the treeline, forming a thin Melt-Freeze crust. In addition, hard old snow surfaces have been exposed and numerous shukabras have formed in areas affected by the February 13-14 storm. Snowfall from today will be on the various snow surface.
Weather
The Japan Meteorological Agency is forecasting winds from the south, slightly stronger, then from the north, cloudy, with snow in the afternoon, and a daytime high of 7 °C (418 m elevation) for northern Nagano Prefecture. At AMeDAS Hakuba (elevation 703 m), the temperature is -3 °C (as of 5:00 am), with no new snowfall in the past 12 hours. At the main ridge (elevation 2,400 m), the temperature is -10°C (as of 5:00), and southwest winds are beginning to blow. The Nagano Prefectural Meteorological Observatory forecast 50 cm of snowfall for northern Nagano Prefecture at 4:35 a.m. on February 17 in the 24-hour period ending at 6:00 a.m. on February 18.
