Autumn rain front

A stationary front that appears along the southern coast of Japan from early September to early October. It is also called the autumn rain front. It is a front that forms when the midsummer subtropical high pressure system moves south and meets the polar high pressure system that has extended into the Sea of ​​Japan and northern Japan. Its origin and nature are very similar to the rainy season front, but it does not last long and its beginning and end are often unclear. The amount of rainfall in eastern Japan is greater than during the rainy season. Heavy rainfall often falls when a typhoon approaches, and there is more rainfall in the early autumn rains than at the end.

[Yo Narumura]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

9月前半から10月前半に日本の南岸沿いに現れる停滞前線。秋霖前線(しゅうりんぜんせん)ともいう。真夏の亜熱帯高気圧が南へ遠ざかり、日本海や北日本へ張り出してきた寒帯高気圧との境にできる前線で、成因や性質は梅雨前線によく似ているが、長続きせず、始まりと終わりが明確でないことが多い。東日本の雨量は梅雨期よりも多い。台風が接近すると大雨を降らせることが多く、秋雨は末期より初期のほうが雨量が多い。

［饒村　曜］

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