Contributions of Atlantic tropical cyclones to monthly and seasonal rainfall in the eastern United States 1960-2007

Tropical cyclone activity in the North Atlantic Basin experiences great variability on intra-annual, interannual, and interdecadal timescales. George Cry found that TC rainfall presents an intra-seasonal pattern over the eastern USA, contributing up to 40% of total monthly rainfall. This study replicates much of what was done by Cry using a denser rain gauge network and more sophisticated techniques for analysis. Rainfall data for this study come from 717 stations from the Historical Climate Network covering 31 states to capture the tropical cyclone (TC) contribution in monthly and seasonal precipitation in the eastern USA. Results showed that September has the highest TC rainfall contribution and the coastal regions of North Carolina, Virginia, and Alabama receive more than 30% of monthly rainfall totals from TCs. Comparisons between 1931-1960 and 1960-2007 study periods show that the storm track density shifted slightly eastward, which explains some of differences between the two analyses.