Abstract
The present study was carried out for the purpose of prediction of rainfall in the “Bai-u season” in Japan, based on the monthly maps of precipitation departure for the period 1913 to 1341. The results obtained are as follows:
There can be seen some relation between the type of precipitation departure in February and that in June: _??_e. When February is characterized by the abundance (or scantiness) of precipitation in the southern part and its vicinity of Japan proper (Fig. 2 and 4) the amount of precipitation in the “Bai-u season ” is considerably great (or small), with the exception for the year 1926. This exception can, however, be explained from
(1) the type of barometric pressure departure in February,
(2) the monthly mean pressure and its gradient direction at Ogasawara in March,
(3) the mean air temperature of the northern air-masses during January and February.
