Observational Analysis of Tropical Cyclone Tornadoes in Gulfport, Mississippi During Hurricane Isaac 2012

On the night of 28 August 2012, Hurricane Isaac made landfall along the Louisiana Gulf Coast as a Category 1 storm. On the afternoon of 29 August 2012, two Tropical Cyclone (TC)-Tornadoes occurred in Gulfport, Mississippi at 1730 UTC and 2215 UTC. Both TC-tornadoes were short-lived, tracked closely to the Gulfport International Airport (KGPT) ASOS station, and had defined low-level rotation signatures present on the National Weather Service Weather Surveillance Radar - 1988 Doppler (WSR–88D) located in Slidell, Louisiana. This project aims to examine TC-tornadogenesis by incorporating hurricane boundary layer (HBL) 0-1 km wind profiles, HBL and surface thermodynamic characteristics, and radar observations of TC-Tornado formation within low-topped supercells in the outer bands of Hurricane Isaac. To better understand the HBL 0-1 km wind profiles, 0-1 km storm-relative environmental helicity (SREH), and the 0-1 km wind shear magnitude, Rapid Refresh (RAP) forecast model soundings from KGPT, 915 MHz radar wind profiler data from The University of Alabama in Huntsville’s (UAH) Mobile Integrated Profiling System (MIPS) along with velocity-azimuth display (VAD) radar wind profiles from the KLIX radar and the UAH Mobile Alabama X-Band (MAX) radar were examined prior to the TC-Tornado times. Additionally, RAP model soundings, NWS New Orleans radiosonde soundings, and microwave profiling radiometer (MPR) data from the MIPS are also incorporated to examine the thermodynamic characteristics of the HBL. To validate and compare the forecast and observed surface conditions near the time of the Gulfport TC-tornadoes, data from the RAP forecast model and the KGPT ASOS station are also incorporated into the study. Immediate results from this study include KLIX radar observations of both Gulfport tornadoes, KGPT ASOS station observations, and RAP model soundings from KGPT. Current research efforts include examining the RAP forecast model output data for tornado forecast validation, KGPT RAP model sounding and MPR data for thermodynamic analysis, and MAX radar data to compute 0-1 km VAD wind profiles. Future work will include a dual-Doppler analysis (DDA) between the KLIX and MAX radars to examine the radar derived wind field prior to and during the 1730 UTC Gulfport tornado. Further, the overall goal of this study is to provide analysis of TC-Tornado formation within high-shear, low-buoyancy environments in the outer bands of TCs, and to provide insight into the validation of forecast model data into forecasting tornadoes within landfalling tropical cyclones.