Recently, several disasters have been caused by sudden heavy rain in short time intervals and ranges. X]band multi]parameter radar had been installed across the country since 2009 to improve the precision of precipitation observations. The integration of this X]band multi]parameter radar into early warning systems that the user can judge intuitively is a key challenge. In this study, we developed techniques that use the radar precipitation difference to detect rain clouds that develop suddenly. This technique is aimed at the development of an index that allows users to judge the severity of the situation. To detect new rain clouds and not simply those in motion, this technique calculated the velocity of the cloud and extracted the areas of clouds that suddenly developed. In addition, we examined the effectiveness of some examples. Using X]band multi]parameter radar, we found that we could provide information on both precipitation and suddenly developing rain clouds.

Key wordsFX]band radar, rainfall, warning, rain cloud developmental quotient