Some Relations between the Movement of Thermal Thunderstorm and that of the Upper Air Current

Abstract

In this paper the present author investigated some relations between the movement of heat thunderstorms which occured in Kwantô district and its neighhourhoods and that of the upper air current by means of the pilot-balloon observations during 3 years from 1930 to 1933.
It is concluded that: a) The direction of the movement of heat thunderstorms coincides with that of upper air current, but it has no relations to surface wind
direction.
b) The velocity of the movement of heat thunderstorm is nearly equal to that of the tipper wind.
c) It is explained that the heat thunderstom whose velocity exceeds 43 km/hour is rarely experienced.
d) The heat thunderstorm is easy to occur when the mean velocity of the upper current is less than 10 m/s, while it scarcely occurs when the mean velocity of the upper current exceeds 12 m/s.
The present study on the relation between the heat thunderstorm and the upper air current may throw a light upon the warning of the thunderstorm, which is now being performed in the selected regions in Japan.