On the Confluent Phenomena of Radar Echoes

The confluent phenomena of radar echoes were observed during the period of special observations on heavy rainfall at the northwestern area of Kyushu Island. The process of the confluent phenomena of radar echoes was clarified by analyzing the data. That is to say, it was recognized that the difference in movement speeds of echoes is due to the formation of new echo cells. As two clouds which were different in growth stage merged with each other, after the confluence the clouds became colloidal unstable and large rain drops were formed rapidly. Namely the cloud physical processes changed with the confluence. 1