Abstract
On the midnight of 16 September 2013, a severe thunderstorm passed over Midori and Kiryu City in Gunma
Prefecture, causing a F1 tonado damage. The change of surface pressure was observed by high dense ground observation network POTEKA. The tornado and misocyclone pressure fields are estimated by using the modified Rankine vortex. The result of this analysis shows that we need to discuss the upper air misocyclone and surface tornado.