The avalanche occurred in backcountry terrain just outside of Tomamu Ski Resort. The avalanche hit mid afternoon, around 3.30pm. Seven of the party were unhurt and one of the party, a French national, was able to ski down to call for help.
The size of the avalanche was substantial, covering 50 metres in length and up to 4 metres wide.
According to the Kyodo News snowfall around the area on Thursday was 6 centimeters in the morning “but could have been much more at a higher altitude and could have easily developed into a surface-layer avalanche, according to the local meteorological observatory.”
“The weather in that part of Hokkaido, has been warmer than usual lately and that probably made the snow unstable” Akihiro Hirakawa, deputy chief of the Furano police station told Reuters.
The Furano Avalanche Center had also posted on Wednesday about potential dangerous conditions in the area.