Some Characters of Strong Winds at MIYAKONOJO

Abstract

From the records of wind speed and direction at Miyakonojo Weather Station in last ten years, some characters of strong wind are obtained.
Maximum mean wind speed over 10m/s is seen in about 50 days during a year, and about a half of these days appers in winter season.
In winter season (December, January February, and March) seasonal wind blows very frequently, their directions are almost W, WNW, NW, and maximum wind speed does not over 20m/s. In summer season (June, Juy, August, and September) mild wind generally blows except when typhoon comes. There are two directions that very strong wind blow out, one is NNE, NE and the other is SE-S-SW, and their speeds some times beyond 30m/s, huge dameges are occured. These facts suggest that wind breaks for prevention of wind damage occured in both winter and summer seasons need two directions.
It is considered that one or two typhoons come to this district every year and the typhoon that the maximum wind speed is about 15m/s comes almost every year, maximum wind speed over 25, 35m/s occure onece per 3-4 years and 20 years.
The duration time of strong wind by typhoon is obtained from 16 typhoons. The time while the wind blows continuously over 10, 15, 20m/s are about 24, 10, and 5 hours respectively.