Lei Zhu1, Qilin Wan2, Xinyong Shen3,Zhiyong Meng1, Fuqing Zhang4, Yonghui Weng4, Jason Sippel5, Yudong Gao2,Yunji Zhang1, and Jian Yue1
1 Laboratory for Climate and Ocean–Atmosphere Studies, Department of Atmospheric and Oceanic Sciences, School of Physics, Peking University, Beijing, China
2 Key Laboratory of Regional Numerical Weather Prediction, Guangzhou Institute of Tropical and Marine Meteorology, Guangzhou, China
3 Key Laboratory of Meteorological Disaster of Ministry of Education, Nanjing University of Information Science and Technology, Nanjing, China
4 Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania
5 I.M. Systems Group, Rockville, Maryland, & National Oceanic and Atmospheric Administration, Environmental Modeling Center, College Park, Maryland
Corresponding author: zymeng@pku.edu.cn(Web Page)
ABSTRACT
The current study explores the use of an ensemble Kalman filter (EnKF) based on the Weather Research and Forecasting (WRF) Model to continuously assimilate high-resolution Doppler radar data during the peak-intensity stage of Tropical Cyclone (TC) Vicente (2012) before landfall. The WRF-EnKF analyses and forecasts along with the ensembles initialized from the EnKF analyses at different times were used to examine the subsequent evolution, three-dimensional (3D) structure, predictability, and dynamics of the storm. Vicente was an intense western North Pacific tropical cyclone that made landfall around 2000 UTC 23 July 2012 near the Pearl River Delta region of Guangdong Province, China, with a peak 10-m wind speed around 44 m s−1along with considerable inland flooding after a rapid intensification process. With vortex- and dynamics-dependent background error covariance estimated by the short-term ensemble forecasts, it was found that the WRF-EnKF could efficiently assimilate the high temporal and spatial resolution 3D radar radial velocity to improve the depiction of the TC inner-core structure of Vicente, which in turn improved the forecasts of the track and intensity along with the associated heavy precipitation inland. The ensemble forecasts and sensitivity analyses were further used to explore the leading dynamics that controlled the prediction and predictability of track, intensity, and rainfall during and after its landfall. Results showed that TC Vicente’s intensity and precipitation forecasts were largely dependent on the initial relationship between TC intensity and location and the initial steering flow.
Citation:Zhu, L., Q. Wan, X. Shen, Z. Meng, F. Zhang, Y. Weng, Y. Gao, Y. Zhang and J. Yue, 2016:Prediction and Predictability of a High-impact Western Pacific Landfalling Typhoon Vicente (2012) through Convection-permitting Ensemble Assimilation of Doppler Radar Velocity, Monthly Weather Review, 144，21-43. (PDF)
