The Analysis of the Rapid Enhancement of Haikui" (1211) Near Sea Shore and Its Related Heavy Rainfall in Zhejiang Province (PAP014358)"

Código

PAP014358

Autores

Qian Yanzhen, Zhang Shengjun, Gao Quanzhu, Jing Liang

Tema

Flood forecasting and early warning systems

Resumo

Severe typhoon HAIKUI(1211)generated on August 3, 2012, near centralmaximum wind increased from 35 ms-1 to 48 ms-1, increased 13 ms-1 during the six hours. Thegust with the intensity above 13 grade has been lasting for 26 hours during the period. Themaximum wind is 46.9 ms-1, and 39.4 ms-1 as well as 36.8 ms-1 respectively at Dongji station,and Dachen station as well as Shippu station, which proof the rapid enhancement near seashore. Analysis shows that rapid strengthening of HAIKUI in offshore due to suddenly increaseof lower water vapor and vorticity input, and high-level divergence. The typhoon wassymmetrical at this stage. The lower-level eyewall was small, while stretching out at upperlevel. At the same time, the radial and tangential wind speed was growing with the warm coreexpanding downward. The vertical speed of the vortex was generally small. All changes of thestructures contributed to the maintenance and development of the typhoon. Development ofTC conducive to the energy accumulation near the center, prompting the lower airflowenhancement and carrying rich water vapor transported to eastern Zhejiang coastal, formedthe heavy rain. The evolution of the top level spiral degrees prompting changes of that of thelow and the increase of 850hPa and decreased to zero for the formation and weaken signal ofthe heavy rain about 9 ~ 12 hours before respectively. Horizontal component of Moist PotentialVorticity(MPV) and wet vector can predict the distribution of rain-band before landfall, wetvector can better reflect the range of precipitation after landfall.