Improving the Vortex Initialization of Hurricane Karl (2010) Through the Assimilation of Tropical Cyclone Vitals Quadrant Wind Radii Estimates.

Robert Nystrom(1)* and Fuqing Zhang(1) and Jason Sippel(2)
(1)Department of Meteorology, The Pennsylvania State University, University Park, Pennsylvania
(2)I.M. Systems Group, Rockville, Maryland, and National Oceanic and Atmospheric Administration/Environmental Modeling Center, College Park, Maryland

Through the use of the Pennsylvania State University (PSU) cycling ensemble Kalman filter (EnKF) and the Weather Research and Forecasting Model (WRF), this study seeks to improve on the prediction of Hurricane Karl (2010). In addition to the traditional assimilation of the minimum sea level pressure and location, contained in the tropical cyclone vitals (TCV), this study will also assimilate the wind radii of the radius of maximum winds (RMW) as well the 34 kt, 50 kt, and 64 kt winds in each quadrant and cardinal direction when available. Through the assimilation of these additional TCV observations in the PSU-EnKF it is believed that the asymmetric structure and size of the vortex will be more realistic and the resulting forecast improved.

*Preference: Oral