Meandering westerlies

この暑さ…ホント，6月？　北海道では本日，37°以上を記録したとか…。ちょっと前までは雪が降っていたのに…。梅雨入りが待ち遠しくなるなんて久しぶりです。

Heat wave continues to blanket the nation

A hot Sunday was followed by a hot Monday, as the mercury rose across the nation once again. Temperatures topped 30 C Monday at 209 spots across wide swathes of the country, including the Kanto and Kansai regions, with 31.3 C observed in Tokyo’s Chiyoda Ward at 12:20 p.m.

Highs have topped 30 C for three straight days in much of the nation. Warm air blew into Japanese skies from both the west and south, sending temperatures up sharply. It is unusual for warm air to come in from the west at this time of year. However, the weather is expected to start changing for the worse and temperatures to return to normal around Thursday in eastern Japan.

According to the Japan Meteorological Agency and the Japan Weather Association, a migratory anticyclone has covered a large portion of the Japanese archipelago since the end of May. The high-pressure system was surrounded by warm air flowing from the south. In addition, warm air from the west, which is usually seen only after the end of the rainy season, also blew into the nation at the end of May. In some parts of China, daily highs topped 40 C.

“Meandering westerlies seemed to have brought heated air from over China to Japan,” said Takashi Nitta, a former director general of the meteorological agency. In addition, a stationary front on the Pacific side of eastern Japan has been holding down the high-pressure system, and is seen as one factor behind the heat wave.

http://the-japan-news.com/news/article/0001324675

「犯人」はここにあるようにmeandering westerliesだそうです。これは「蛇行する偏西風」ですね。「偏西風の蛇行」が起きる原因は結局は人間活動。クルマ好きは肝に銘じます。（UG）