Testing and Evaluation of the GSI-Hybrid data assimilation for the Hurricane Forecasts

HFIP (Hurricane Forecast Improvement Program) works on improving the accuracy of hurricane forecasts through coordinating the efforts of the hurricane research groups and the operational centers. Data assimilation is the crucial part of this effort through improving the initial fields. Different data assimilation schemes are being used by various modeling groups, including the hybrid-3DVAR, which adds the flow-dependent information from the ensemble perturbations to the static background error covariances. In this work, GSI (Gridpoint Statistical Interpolation)-Hybrid is applied for HWRF (WRF for Hurricanes) and the performance is evaluated in comparison with the GSI applied for HWRF. Retrospective cases will be run and preliminary results will be presented.