Predicting the Gulf of Mexico Hurricane Season With 500‐hPa Temperature

Abstract

AbstractWhile North Atlantic tropical cyclone (TC) forecasts are numerous, the number of Gulf of Mexico (GOM) storms is normally left ambiguous. Motivated by the 2020 GOM hurricane season, this study introduces two methods of anticipating upcoming GOM TC frequency on June 1 of each year: (a) statistically transforming Climate Forecast System (CFS)‐predicted June–November GOM 500‐hPa temperature (T500); and (b) applying a 0.284 multiplier, the climatological proportion of GOM versus North Atlantic TCs, to a representative, widely circulated North Atlantic‐wide forecast. Both methods perform skillfully, especially given their simplicity. Though warm T500 normally inhibits deep convection and is not generally considered among statistical TC forecasts, it is comparatively well represented by modeling systems. Additionally, T500 is well correlated with traditional, yet less accurately resolved, TC environmental parameters. While unfavorable to individual TCs, T500 generally (though indirectly) indicates several difficult‐to‐model physical aspects of more favorable GOM TC environments.