Impacts of an Airborne Doppler Wind Lidar on Tropical Cyclone Analyses and Forecasts

The initial structure of Tropical Cyclones (TCs) in numerical models remains a limiting factor for TC forecasts. Instruments flown on the NOAA’s P3 Orion Hurricane Hunter Aircraft provide in situ inner-core observations of Atlantic TCs.  The Tail Doppler Radar (TDR) provides the most comprehensive coverage of the wind field in TCs.  TDR has the ability to measure winds in areas of precipitation but outside of these regions and below about 1 km, it either cannot make observations or the data is less reliable.  Doppler Wind Lidar (DWL) was flown in two West Pacific typhoons in 2008.  Pu et al. (2010) showed short-term improvements in TC track and intensity forecasts by assimilating DWL data.  In the 2015 and 2016 hurricane season, an airborne DWL was flown for the first time on the P3 Orion into TCs of different intensities in the Atlantic and East Pacific.  This study presents results that demonstrate the impact of airborne DWL measurements on the numerical simulations of the sampled TCs.  Using the Hurricane Weather Research and Forecast (HWRF) model and different data assimilation systems, results show DWL data as a complementary observation set to data from the TDR.