Statistical Characteristics of Unusual Tropical Cyclone Tracks in Offshore Guangdong

Statistical analyses are made on unusual tropical cyclone tracks with sudden changes of directions in offshore Guandong based on the data from Typhoon Almanac for the period of 1949 to 2000. Studies are also carried out on characteristics of intensity, moving speed, offshore distance, and turning points of typhoons with unusual tracks, as well as their relationships. Meanwhile, the impact of topography in the Guangdong coastal area on tropical cyclones is also studied. The results show that the locations where these tropical cyclones turned suddenly (or close to the coast) were concentrated in mountainous coastal areas, and tropical cyclones tend to slow down when they approach the coast. It is also shown that prior to turning, the more intense the tropical cyclones are, the closer the turning points are to the coast, and the smaller incident angle they need. In addition, near the coast, the slower the tropical cyclones move, the more markedly they turn.