Hurricane WRF (HWRF) rapid intensification: verification and diagnostics

Tropical cyclones are a serious concern for the nation, causing significant risk to life, property and economic vitality. In the last 10 years, the errors in hurricane track forecasts have been reduced by about 50% through improved model guidance, enhanced observations, and forecaster expertise. However, little progress has been made during this period toward reducing forecasted intensity errors. To address this shortcoming, NOAA established the Hurricane Forecast Improvement Project (HFIP) in 2007. HFIP is a 10-year plan to improve one to five day tropical cyclone forecasts, with a focus on rapid intensification and rapid weakening (RI/RW).

The operational Hurricane WRF (HWRF) model's skill in forecasting RI/RW has not been extensively evaluated. In this study, the ATCF format tracks generated from the HWRF operational forecasts and its experimental high resolution 3-nest forecasts are compared with the National Hurricane Center (NHC)'s working best tracks. The HWRF model's ability of forecasting RI/RW in these two configurations is evaluated. Case-based diagnostic studies are conducted to investigate why the HWRF model is able to capture RI/RW in some cases but not able in others. The result of this study will provide insight as for how the HWRF model can be improved so that it can better forecast RI/RW events.