Report: Frequency Of Torrential Rain In Japan Doubled Over 45 Years
A Japanese meteorologist says the frequency of localized torrential downpours in Japan has more than doubled in 45 years.
The director of the typhoon and severe weather research department at the Meteorological Research Institute, Kato Teruyuki, published a report on changes in Japan's precipitation patterns between 1976 and 2020.
He used precipitation data collected by the Automated Meteorological Data Acquisition System, or AMEDAS, at about 1,300 locations across Japan.
He defined rainfall of 130 millimeters or more over a three-hour period as a localized torrential downpour.
In 2020, this type of downpour occurred 67.7 times. The figure for 1976 was 31.5.
Torrential rain is more likely to occur during the rainy season in June and July. The frequency of torrential downpours was nearly four times greater during these two months.
Kato says global warming has caused sea water temperatures to rise and create more moisture, developing a band-shaped precipitation system, and the phenomenon is more likely to bring heavy rain during the rainy season.
He says the data shows a remarkable increase in localized torrential downpours that could cause landslides and flooding.
He says the band-shaped precipitation system is likely to bring downpours to areas that have never experienced them before.