Abstract
Japan Meteorological Agency has modified their statistical policy on tornadoes and tried to figure out the actual condition from then. In US, to append damage indicators and to fix inconsistency of rating tornadoes and overestimate of wind speeds, Enhanced Fujita Scale was proposed and commonly used nowadays. In Japan, to make clear the actual situation of tornadoes and describe their intensities and effects to buildings and other structures, review and improvement have been started for the Fujita Scale considering typical Japanese climates and other situations. In this report, structures other than buildings were selected as damage indicators (DI) of tornadoes, and basic concepts to evaluate their degree of damage (DOD) and corresponding wind speeds were explained.
