Intercomparison of Observations between the Air Force and NOAA Hurricane Hunter Aircraft

For the first time, the Air Force and NOAA reconnaissance aircraft flew an intercomparison flight over the Gulf of Mexico in June of 2024 in an effort to standardize the calculation of important flight-level measurements used by forecasters and numerical models. An investigation into the computation of virtual temperature within the separate flying units revealed differences in the methodology. These variations could lead to discrepancies in dependent variables, such as the extrapolated sea-level pressure, a measurement that is often used for operational decisions. To compare and verify the observations, two aircraft flew at the same altitude over the same ground track through a relatively uniform environment and each released a dropsonde at staggered intervals. Flight-level winds (averaged over various frequencies), temperatures, and moisture were compared to each other, the dropsondes released, and the Stepped Frequency Microwave Radiometer (SFMR). While the flight-level wind observations compare quite well, differences appear between the various thermodynamic measurements. Reasons for the discrepancies are explored in order to achieve the future goal of better standardizing data collected by the flying units to generate reliable observations for hurricane operations.