Vortex-scale hurricane data assimilation: Real-data results using combined NOAA/AOML/HRD HWRF-X regional and NOAA/ESRL GFS global ensemble Kalman filter systems

The Hurricane Research Division (HRD) at NOAA/AOML has developed a state-of-the-art ensemble Kalman filter (EnKF) data assimilation system that provides high-resolution vortex analyses as initial conditions to the experimental version of Hurricane Weather Research and Forecasting (HWRF-X) regional hurricane model that is being advanced at HRD. The high-resolution inner-core data that are assimilated comprise of flight-level, dropsonde, Doppler radar wind, and Stepped Frequency Microwave Radiometer (SFMR) surface wind speed observations and are obtained from flight missions by NOAA's P-3 aircraft. The global one-way interface to HRD's hurricane analysis/modeling system is provided by the EnKF for the Global Forecast System (GFS) developed at NOAA's Earth System Research Laboratory (ESRL). The global EnKF assimilates all of the observations used in the operational global NCEP analysis, and is run at the same resolution as the operational GFS control forecast. This combined regional-global hurricane modeling configuration is planned to be run semi-operationally as part of NOAA's Hurricane Forecast Improvement Project (HFIP) demonstration system during 2010 hurricane season.

In this talk, we will describe planned operational specifications of the HWRF-X/GFS EnKF systems and present real-data assimilation and forecast results for Hurricane Bill and Tropical Storm Danny of 2009, focusing on data impact on short-term structural and long-term track and intensity evolutions.