TOKYO - Heavy rain intensified across the Tokai and Kanto regions on September 9, with locally developed rain clouds bringing wind-driven downpours to Gifu Prefecture and steady rain to Tokyo, while forecasters warned that another round of strong rain could reach Kanto during the night.
In Gero, Gifu Prefecture, a report received shortly after 3 p.m. described intense rain being driven sideways by strong winds. The conditions were severe enough to make it difficult to use an umbrella.
The area also experienced heavy rain on September 8, making September 9 the second consecutive day of intense downpours.
In Tokyo's Meguro Ward, a report shortly after 3 p.m. said rain was already falling heavily and the air felt warm and humid.
The unstable conditions are being influenced by a front in the upper atmosphere, even though the surface front remains farther to the south.
Differences in air masses around the upper-level front are also contributing to stronger winds in some areas.
In Kanto, a shear line, or zone where winds converge, has formed south of the main front. The convergence is causing rain clouds to develop locally and producing areas of strong rainfall.
Radar observations during the afternoon showed developed rain clouds concentrated particularly over the Tokai region, while rainfall in Kanto was being driven more by the shear line.
The strongest rain in Tokai is expected to gradually shift from west to east, with periods of heavy rain continuing through the evening.
Kanto is expected to see the first band of rain move away temporarily, providing a brief lull.
However, the area of rain clouds currently developing around Tokai is forecast to move eastward during the night, bringing a second period of heavier rain to Kanto.
The rain is expected to move offshore around midnight, meaning Kanto could experience two distinct periods of significant rainfall during the evening and nighttime hours.
Residents in both Tokai and Kanto are being advised to remain alert to rapidly changing weather conditions, particularly during the evening commute, as the area of heavy rain expands and strong winds accompany some of the downpours.
Source: ウェザーニュース
