Abstract
Meteorological characteristics of the formation and environment of the Niigata-Fukushima heavy rainfall on 28~30 July 2011 were studied. Line-shaped rainfall systems were observed by using synthetic radar and Xband MP radar on 29 July at 09~17 and on 30 July at 00~04. The purpose of this study is to classify these events and to reveal the reason why these occur and stagnate. It was found that the former event can be classified as Back Building type while the latter can be classified as Back Building composite type. The development environments were focused by the convergence, relative humidity, wind and temperature by using the Japan Meteorological Agency GPV mesoscale model dataset. Results indicate that convergence area, flow of high-humidity air at 950hpa and incursion of dry-low-temperature air generated the event on 29 July at 09~17. The event on 30 July at 00~04 was generated by the effect of cold air at 400hpa which flowed into high-humidity region.
