The Impact of HS3 Data Upon HWRF Forecasts

The project examines the impact of assimilating data from NASA's Hurricane and Severe Storm Sentinel (HS3) field campaign into the Hurricane Weather Research and Forecast System (HWRF). The Global Hawk (GH) is unique among hurricane reconnaissance aircraft because of its 26-h endurance, which is two to three times that of other operational reconnaissance aircraft. The HWRF employs a hybrid 3DVAR data assimilation system that began operational assimilation of GH-based dropsondes during the 2015 hurricane season.

Several different types are data are assimilated. Past tests with GH-based-dropsondes have shown generally positive impact on the track and intensity forecasts, and this work will be extended with the 2015 version of HWRF. In addition, this project assimilates wind data from the High-Altitude Wind and Rain Airborne Profiler (HIWRAP) and surface wind speeds from the Hurricane Imagine Radiometer (HIRAD). This is an extension of recent work using an ensemble Kalman filter (EnKF) to assimilate data from Hurricane Karl into the Advanced Research WRF (ARW). The results showed that assimilating data from these sources can significantly improve hurricane analyses and forecasts, especially when data from multiple sources is simultaneously assimilated.