Abstract
High and middle tropospheric conditions of temperature and wind fields are analysed in detail for heavy rainfall cases of 26 June and 17 July 1953. In these cases the subtropical upper frontal zone is observed in the vertical cross sections in its well defined form. It is suggested that the vertical motion associated with this upper frontal zone might be one of the factors which induce the heavy rainfall over west and central Japan during the rainy season in early summer.
