Author(s): Qinglan Li; Pengcheng Xu; Xingbao W Ang; Hongping Lan; Chunyan Cao; Guangxin Li; Lijie Zhang
Linked Author(s):
Keywords: Tropical cyclone; Wind gust forecast; South China; Distance; Azimuth; Gale occurrence probability
Abstract: This study tries to supply a quantitative forecast method through an investigation of the relationship between the wind gusts observed at the automatic weather stations (AWSs) and TCs’main characteristics, i. e. ,TC intensity, TC distance to the station, TC’s azimuth relative to the station. Historical TCs data from 1968 to 2013 within the distance of 700KM to several AWSs in South China are analyzed. The wind gust data for the same period at six coastal AWSs: Yantian International Container Terminal (YICT) ,Mawan Port (MWP) ,Shekou Ferry Terminal (SFT) in Shenzhen and Hong Kong Observatory (HKO) ,Cheung Chau Island (CCH) ,Waglan Island (WGL) in Hong Kong, are used to build the statistical relationship between the wind gusts and TCs’main characteristics. The relationship between the wind gust and TCs’main characteristics are clearly illustrated with novel figures in which the local wind observations are projected onto the TC’s track. The probability of gale occurrence (wind gust> =17m/s) at these six stations are also computed and synthesized in figures. Analyses results show that the wind induced by offshore TCs is strongly affected by the surrounding circumstances of the stations. In North Hemisphere, the wind gust observed at AWS is weaker if the land is at its Southeast. By contrast the wind gust observed at AWS is stronger if its Southeast is open water. Usually, Hong Kong coastal stations, which are more open to the South China Sea, suffer more from wind gusts induced by TCs than the coastal stations in Shenzhen. The most dangerous area is Northeast quadrant of TCs. At this quadrant, Typhoons which is at the distance of more than 400kms might incur gale at coastal stations in South China.
Year: 2015