Performance of the Advanced Operational HWRF Modeling System during pre-implementation testing and in real-time 2007 hurricane season

The advanced Hurricane Weather Research and Forecasting (HWRF) modeling system with high-resolution movable nested grid, developed at the Environmental Modeling Center (EMC) of the National Centers for Environmental Prediction (NCEP), became operational during the 2007 hurricane season. In the pre-implementation phase (transition to operations (T2O)), more than 1800 HWRF forecasts were made for storms during the 2004-2005-2006 Atlantic and East Pacific hurricane seasons and the results were extensively compared against the GFDL forecasts. The storm track and intensity forecasts from HWRF during T2O have shown comparable skill to the bench-mark GFDL forecasts, as required by Tropical Prediction Center (TPC) for operational implementation.

In real-time, HWRF forecast guidance on storm track and intensity was provided to the National Hurricane Center (NHC) four times a day for forecast periods out to five days for all the storms in Atlantic and East Pacific basins for the year 2007. The advanced operational HWRF model is coupled to the operational Princeton Ocean Model (POM) for the Atlantic basin Relevant to this coupling, advanced physics for the air-sea interactions was also implemented in the advanced operational HWRF modeling system.

Performance of the HWRF modeling system, some of its salient features, and its sensitivity to various components of the system including the initialization (3DVAR) and coupling to POM are presented for selected cases during T2O experiments and during real-time 2007 hurricane season.