Avalanche Bulletin
更新日時: 2024/03/11 05:30
Hakuba
Alpine Low Pay attention to the effects of solar radiation
Treeline Fair Note the effects of elevated temperature and solar radiation.
Below Treeline Fair Note the effects of elevated temperature and solar radiation.
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
This is a day of high avalanche conditions in certain terrains. Strong sunshine and significant temperature increases are forecast. Surface snow that was low cohesion and very soft in the morning may become more responsive to human stimulation as slab features intensify during the day. Terrain selection should be made by considering where the terrain has features such as convex or isolated terrains that are less able to support snow accumulation, and the impact of these features with solar radiation. This morning the snow has cooled well due to radiative cooling. If you choose the right terrain, you will be able to enjoy fresh snow that is so fresh it is hard to believe that it is March. Please remember basic group management such as stopping at safe spots and skiing one person at a time. Have a great day.
Avalanche Problem
ストームスラブ Storm slab
On very steep slopes where the influence of solar radiation is strong, slab avalanches can occur at the interface between the storm snow and the crust buried under the new snow. Avoid terrains with convex or isolated geometries that do not support snow accumulation.
ウインドスラブ Wind slab
Strong northwest winds on the main ridge have subsided since yesterday around noon. Currently, the wind is also very light. Watch for the formation of hourly wind slabs.
持続型スラブ Persistent slab
Snowfall from the night of March 8 through the morning of March 10 buried the weak layer in question deeply. This has greatly reduced the triggering sensitivity and increased uncertainty. The avalanche bulletin team will continue to attempt to track this persistent slab for some time to come.
概要
Avalanche
Yesterday (10th), a size 1 loose snow avalanche was observed due to snowfall since dawn. Alpine has no observation information due to poor visibility.
Snowpack
The upper layer of snowpack has new snow (50-80 cm) since the evening of March 8. Below treeline, no significant vulnerability has been reported within this new snow. However, in the upper part of the treeline, a layer of Melt-Freeze from the March 8 fine weather is buried on the steep slopes, and faceted snow is forming on the boundary of this layer. As of yesterday, a sound similar to a whumpfing and some cautionary test results were noted, and caution is advised. The weak layer of persistent slab that we are tracking is buried at about 120-180 cm and remains highly uncertain.
Weather
The Japan Meteorological Agency is forecasting southerly winds, later northerly winds, clear skies, cloudy in the evening, and a daytime high of 11 ºC for northern Nagano Prefecture. At 703 m elevation (Hakuba), the temperature is -11.5 °C (as of 5:00), with no new snowfall in the past 12 hours.
