Warm winter It is difficult for cold to flow into the vicinity of Honshu.

In this winter, temperatures are extremely high, mainly in eastern and western Japan, and snowfall has decreased to record levels, with less than 20% of average snowfall at many points on the Sea of ​​Japan side. The Japan Meteorological Agency has analyzed that it was difficult for cold air to flow near Honshu by phenomena called "westerling of the westerly wind" and "positive Arctic Oscillation", and the same tendency is likely to continue next month.

According to the Japan Meteorological Agency, it has been reported that this winter is warmer and record less snowy due to weak southern cold air near Honshu for two reasons.

The first one is "Western meandering".

In normal years, the westerly wind blowing from Kyushu to the sea south of Kanto is blowing from the Sea of ​​Japan to the northeast this season, and it is said to be in a state of blocking the southern part of the cold so to speak. That is.

Another is the "Arctic Oscillation".

This is a phenomenon in which barometric pressure near the North Pole and mid-latitude regions fluctuate with each other like a seesaw.This month, the condition called `` positive Arctic Oscillation '' where the pressure near the North Pole is low and the pressure at the mid-latitude is high becomes clear, This means that the chill is less likely to flow.

The average temperature this month until November 23 was 1.2 degrees higher in northern Japan and 2.2 degrees higher in both eastern and western Japan compared to the normal year, and the amount of snowfall from November last year to 23 this month was At many observation points around the side, it is record low, less than 20% of the normal year.

According to the Japan Meteorological Agency, the westerly wind meandering and the positive Arctic Oscillation are expected to continue into the next month, with higher temperatures and less snow.