Graphical Abstract
Hatsuzuka, D., R. Kato, S. Shimizu, K. Shimose, 2022: Verification of forecasted three-hour accumulated precipitation associated with “Senjo-Kousuitai” from Very-Short-Range forecasting operated by the JMA. J. Meteor. Soc. Japan, 100, 995-1005.
https://doi.org/10.2151/jmsj.2022-052.
Early Online Release
Graphical Abstract
Plain Language Summary: In recent years, “senjo-kousuitai”, characterized as band-shaped areas of heavy rainfall, have frequently caused river floods and landslides in Japan. A challenge for mitigating and preventing such disasters is to forecast accumulated rainfall for several hours with an adequate lead time. This study investigated the usefulness of the immediate very-short-range forecast of precipitation (VSRF), issued by the Japan Meteorological Agency, in terms of prevention of senjo-kousuitai disasters. The usefulness was assessed based on forecast accuracy of 3-h accumulated rainfall for a threshold value of 80 mm at each forecast time (FT; i.e., 1–6 h), using various verification indices.
Highlights:
- We analyzed 21 senjo-kousuitai events that occurred in Kyushu in 2019 and 2020.
- The VSRF produces useful forecasts of heavy rainfall associated with senjo-kousuitai for up to 2 h ahead (i.e., ETS ≥ 0.3 for a threshold of 80 mm (3h) –1).
- Further analysis found that the VSRF is less skillful in the formation stage of senjo-kousuitai even at short FTs, primarily because of poor performance of extrapolation forecast.