The 12–14 March 1993 Superstorm: Performance of the NMC Global Medium-Range Model

Abstract

The performance of the NMC Global Medium-Range Model in forecasting the March 1993 ?superstorm? at various lead times is assessed. The forecasts of mean sea level pressure, 1000?500-mb thickness, 500-mb geopotential height and vorticity, 850-mb wind and streamfunction, and precipitation are described, Forecasts of storm track and intensity are shown, and comparisons with the European Centre for Medium-Range Weather Forecasts and the U.K. Meteorological Office forecasts are made. It is shown that the main features of the storm and the planetary-scale developments leading up to it were accurately predicted as much as five days in advance, especially north of its track, but that there were significant underestimates of the early stages of its development in the Gulf of Mexico.