Analysis of a Line-shaped Rain Echo Extending in the NE Direction from Higashi-Nagasaki in Kyushu, Japan

A line-shaped rain echo, which extends in the northeastern direction from Higashi-Nagasaki and lasts as long as seven hours or more over the same location, was studied in the viewpoint of a topographical enhancement of rain clouds. Main results are as follows. (1) On 2 July 1995, long-lasting line-shaped rain echoes were observed by our RHI and marine radars. These echoes existed over the same ragion from Higashi-Nagasaki to the NE. direction of Isahaya and Konagai area. (2) These echoes consisted of small convective echoes which moved from SW to NE.. The direction of the line agreed with the direction of the movement of individual echoes and with upper wind conditions. (3) The features of these rain echoes and the weather conditions are strongly suggesting the topographical enchancement of rain formation by a deep valley at the Nagasaki Peninsula