Characteristics of Summertime Afternoon Rainfall and Its Environmental Conditions in and around the Nobi Plain

Abstract

This study investigates the characteristics of local-scale afternoon rainfall and its environmental conditions in and around the Nobi Plain under synoptically undisturbed conditions in summer by using operational meteorological data. The analysis of radar/raingauge analyzed precipitation data revealed that strong rainfall occurs over the mountain slopes in late afternoon and in the northern part of the Nobi Plain in early evening, while light rain frequently occurs around the mountain peaks in early afternoon. Examining mesoscal analysis data indicated that the primary difference in the environmental conditions that distinguish between rain and no-rain days is middle-level moisture field, with moister condition being found on rain days. Because of the significant difference in the middle-level moisture, stability index is useful in distinguishing the environmental conditions between rain and no-rain days.