News Discussion

Japan's Rainy Season Delayed: Latest Forecast

According to the Japan Meteorological Agency's (JMA) latest forecast on June 10, the Kanto-Koshin region is expected to enter the rainy season around June 16. This is eight days later than the usual onset of the rainy season, which typically occurs around June 7.

If the rainy season front does not move northward by June 16, some areas may see temporary clear skies due to high pressure. This could result in a significant delay in the start of the rainy season, especially in regions like Kanto-Koshin.

According to the JMA, this year, the northward extension of the Pacific high-pressure system is weaker. Additionally, the westerly winds are meandering further south than usual, causing a delay in the northward movement of the rainy season front.

The JMA forecasts the stationary rainy season front, lingering south of Japan's Nansei Islands, will move northward towards Honshu after June 15. This shift is expected as the Pacific high-pressure system strengthens. It also anticipates that the rainy season will begin in Kyushu to Kanto around this time, at the earliest.

If the rainy season starts after June 17, areas like Kanto-Koshin could experience it beginning in late June. Rainy season onset in the Kanto-Koshin region occurred as late as June 22 in 1967 and 2007, a phenomenon not observed for 17 years.

Northern Kyushu and the Chugoku region are expected to experience the start of the rainy season around June 16. This would mark the fifth latest recorded occurrence in the respective areas.

Across all regions, the onset of the rainy season is anticipated to be later than usual this year. Okinawa and Amami have already entered the rainy season, experiencing delays of nine and eleven days, respectively, compared to most years. Additionally, southern Kyushu, also delayed by nine days, and Shikoku, delayed by four days, have seen the start of the rainy season.

1. 1. forecast 予報、予測、天気予報、予想する、予測する
   Economists often attempt to forecast future market trends.
2. 2. temporary 一時的な、仮の
   The construction work will cause temporary traffic delays.
3. 3. meander 蛇行する、曲がりくねって流れる、あてもなくさまよう
   The path meanders along the coastline, offering beautiful views.
4. 4. anticipate 予期する、予想する、楽しみにして待つ
   We anticipate a large crowd at the concert tonight.
5. 5. recorded occurrence 記録された出来事
   The recorded occurrence of a solar eclipse helped historians date ancient events.

1. 1. If the rainy season front does not move northward by June 16, what might some areas experience?
2. 2. Why is there a delay in the northward movement of the rainy season front?
3. 3. When did the rainy season onset occur as late as June 22 in the Kanto-Koshinregion in the past?
4. 4. In your opinion, what could be the possible reasons for the changes in the usual weather patterns?
5. 5. How do you prepare for the rainy season, and does a delay like this year’s change your preparations?

日本気象協会が６月１０日発表した最新の梅雨入り予想では、関東甲信地方は６月１６日頃に梅雨入りするとした。平年（７日頃）よりも８日遅い。ただ、梅雨前線が本州付近に北上する１６日頃の梅雨入りが見送られると、その後は一時的に高気圧に覆われ、晴天に恵まれる地域が多くなるため、関東甲信などの梅雨入りが記録的に遅くなる可能性もあると分析している。

同協会によると、今年は太平洋高気圧の北への張り出しが弱く、偏西風が平年より南へ蛇行している影響などで、梅雨前線の北上が遅れている。南西諸島～日本の南に停滞した梅雨前線は１５日以降、太平洋高気圧が強まることで本州付近に北上すると見込んでおり、早ければこのタイミングで九州から関東にかけて梅雨入りすると予想している。

ただ、１７日以降に梅雨入りが見送られると、関東甲信越地方などの梅雨入りは６月後半にずれ込む可能性があるという。同地方の一番遅い梅雨入りは昭和４２年と平成１９年の６月２２日で、今月後半の梅雨入りになると１９年以来、１７年ぶりとなる。中国地方や九州北部は１６日頃の梅雨入りとなると過去５番目に遅い記録になるという。

今年は全地域で平年より梅雨入りが遅くなると予想されており、すでに梅雨入りした沖縄・奄美（平年より奄美は９日、沖縄は１１日遅い）、九州南部（同９日遅い）、四国（同４日遅い）も平年より遅かった。