Abstract
　The northern coast in Akita Prefecture suffered severe disaster caused by tornadoes on January 11, l987. This paper deals with the outline of meteorological conditions and damages in relation to the tornadoes.
　The following main results were obtained:
1) According to the synoptic situation associated with its occurrence, the tornadoes can be assumed the cold air tornado related to an upper cold voltex.
2) rom the feature of tornado damage path, it seems that the cumulonimbus system with respect to a mesocyclone produced six tornadoes, one after another.
3) The each damaged area seems to be one straight narrow belt. The length of the each damaged area is about 300-700 m and the width is at most 50-l00 m, and the narrow belts turn to the southeast or east-southeast.
4) The zinc roofs and window glasses are destroyed and the many simply constructed storehouses for farmers are adso destroyed. The damage to the power transmission line is serious, though the damage occurred before daybreak.

【キーワード】：竜巻, 竜巻災害, 風害, 気象災害

*秋田大学鉱山学部
Mining College, Akita Univ.
**秋田大学教育学部
College of Education, Akita Univ.
***東北大学工学部
Faculty of Engineedng, Tohoku Univ.