Avalanche Bulletin
更新日時: 2025/03/09 07:00
Niseko Yotei Yoichi Shiribeshi
Alpine Fair Limited alpine observations.
Treeline Good
Below Treeline Good
信頼度：○ good □ Fair △ Low
Travel and Terrain Advice
The storm snow is settling and bonding to the crusts but rising temperatures and rain at lower elevations will weaken the upper snowpack today. Beware of falling tree bombs as the warm temperatures will cause these to continue falling today adding to the many frozen tree bombs lurking within the storm snow.
Avalanche Problem
ウインドスラブ Wind slab
North winds have shifted to the West and will move to the SW later today re-distributing recent storm snow.
点発生湿雪雪崩 Wet Loose snow
Rising temperatures and rain at lower elevations will weaken the snowpack and cause loose wet avalanches to be likely later in the day.
概要
Avalanche
A large size 2.5 natural windslab avalanche likely triggered by a cornice failure was reported to have occured near Shimamaki. The avalanche started on a SE aspect in the alpine and ran full path. A smaller size 1.5 natural storm slab avalanche was reported on a NE aspect in the Kiroro area starting at 900m. There were no involvements in either avalanche.
Snowpack
Storm snow in the Niseko range has settled to ~25cms over the March 3 Melt freeze crust and a layer of facets has been found below that crust. In the Kiroro area, storm snow totals have settled to ~45cms. In both areas, the storm snow sits over a melt freeze crust up to 1100m on solar aspects and 8-900m on polar aspects. Some parts of the region that have received solar input in recent days have additional, thinner crusts on solar aspects. The mid and lower pack are well consolidated.
Weather
A high pressure system approaching from the SW pushes a warm Westerly flow across the region today. Valley temperatures will rise to a high of +3C today. Skies will be mostly overcast today with light snow or rain at lower elevations starting around mid-day.
