Characteristic features of the surface wind in a tropical storm of Typhoon 9119 in Nagasaki districts

A very severe tropical storm, Typhoon 9119 (Mireliie), made landfall on the west coast of Nagasaki prefecture on 27 September 1991. This storm caused the most intensive damages in recent 30 years in Japan. The purpose of this study is to investitgate the characteristic features of the surface wind in Nagasaki districts at this event. The results are summarized as follows. (1) The extreme of the mean wind speed was 49.7m/s at Nobozaki (Station 18) and the extreme of gustiness was 67.8m/s at Ikeshima (Station 9), an island near the coast. The very strong gustinesses were observed at the southeastern region of 25 km distance from the center of Typhoon. (2) The observational results showed that the weak wind region around the center has a radius of 15km and the strongest wind region extends from 22 to 62 km form the center. (3) The gust factor observed in this storm ranged from 1.3 to 1.7 at the stations located at hill top, small island and airport. On the other hand, the stations located in the city had the values of 2.0 or more, which reflecting their topographical and/or urbanized situation. (4) The dip of pressure accompanied with the main tropical cyclone at a distance of 200km, caused an additional storm 3 hours later. This fact should be kept in mind for establishing the careful watches of wind disasters