Historical Hurricane Trends and Variability

Accurate records of basinwide Atlantic and U.S. landfalling hurricanes extend back to the mid-1940s and the turn of the century, respectively, as a result of aircraft econnaissance and instrumented weather stations along the U.S. coasts, espectively. Such long-term records are not exceeded elsewhere in the tropics. The Atlantic hurricanes, U.S. landfalling hurricanes and U.S. normalized damage time series are examined for interannual trends and multidecadal variability. It is found that only weak linear trends can be ascribed to the hurricane activity and that multidecadal variability is more characteristic of the region. Various environmental factors including Caribbean sea level ressures and 200mb zonal winds, the stratospheric Quasi--Biennial Oscillation, the El Nino-Southern Oscillation, African West Sahel rainfall and Atlantic sea surface temperatures, are analyzed for interannual links to the Atlantic hurricane activity. All show significant, concurrent relationships to the frequency, intensity and duration of Atlantic hurricanes. Finally, much of the multidecadal hurricane activity can be linked to the Atlantic Multidecadal Mode - an empirical orthogonal function pattern derived from a global sea surface temperature record. Such linkages may allow for prediction of Atlantic hurricane activity on a multidecadal basis.