Abstract
In the early autumn or the “Shurin” season of 1951, Japan was dominated by abnormal coolness and persistent rain for a month. In the present study, this abnormal weather condition is investigated based primarily on the 5-day mean and 15-day mean 500 mb charts from the view-point of seasonal, change of pattern from summer to Shurin season.
As a result, the world-wide shift of flow pattern is found to be responsible to the seasonal weather change in Japan. Furthermore, it is shown that the typhoon appearing in the late summer does a trigger action to the seasonal change of westerlies, causing cold air to shift southward and warm air northward, which is the main cause to bring about a seasonal change in large-scale pattern and seasonal weather change in Japan.
