The HWRFx Modeling System: The High Resolution Hurricane Forecast Test

The Hurricane Weather Research and Forecasting Experimental system (HWRFx) is the experimental version of the NCEP's HWRF system specifically adopted and developed at OAR to study the hurricane intensity change problem. Three sets of parallel experiments were designed to assess the impact of the horizontal resolution on hurricane forecast of intensities, locations and structures by using the HWRFx. High resolution hurricane forecast (HRH) test 69 cases encompassing ten storms in 2005 and 2007 independently selected by hurricane specialists were simulated at three different resolution configurations: 27-km with a 9-km moving nest, which conforms to the resolution of the operational hurricane forecast model, HWRFTM; 9-km with a 3-km moving nest; 9-km with a 3-km moving nest, in which a 1-km moving nest is embedded. Results obtained from these experiments indicate that higher model resolutions can statistically improve five-day forecasts of both track and intensity. Preliminary analyses of simulated intensity changes and structures in all 69 cases also demonstrate more realistic scenarios. Further evaluations of HRH tests cases are currently underway.