Simulating tropical storms in the Gulf of Mexico using analytical models

ABSTRACT Different analytical models have been evaluated for estimating wind speed of the tropical storm, where the storm-induced wind velocity is calculated as a function of distance from the center of the hurricane. For these models, different parameters such as maximum wind speed, a radius of the maximum wind, hurricane shape parameter, hurricane translation speed and the orientation of the trajectory, etc., affect the shape of a hurricane. Hurricanes Lili (2002), Ivan (2004), Katrina (2005), Gustav (2008) and Ike (2008) from the Gulf of Mexico were used for skill assessment. The maximum wind radius was calculated using significant wind radii (R34, R50 and R64) reported by the National Hurricane Center. Different formulas for calculating the radius of maximum wind speed were evaluated. The asymmetric wind field for each hurricane was generated using analytic methods and compared with in situ data from buoys in the Gulf of Mexico and the H*Wind data. Analytical models were able to predict high wind speed under tropical cyclone conditions with relatively high precision. Among the analytical models evaluated in this research, the model proposed by Holland et al. (2010) showed excellent results. Dynamical wind models such as NCEP/NARR provide wind speed with the coarse spatial resolution which is acceptable for far-field locations away from the hurricane eye. In contrast, analytical models were able to produce sufficiently reliable wind speed within a particular radius from the center of the hurricane. Therefore blending of dynamical and analytical models can be used to provide accurate wind data during hurricane passage in the Gulf of Mexico.