| Abstract: | The interannual variability in warm-season soil-moisture deficits were examined for the Southern United States from 1895-2005. Moisture deficit values are computed using the Thornthwaite/Mather water budget technique. Five soil-moisture deficit regions were identified, each has a distinct pattern and magnitude of deficit. No long-term trends were evident but considerable interannual variability is observed. Severe deficits across the South are associated with high potential evapotranspiration in addition to reduced rainfall. The reduced precipitation across the region is associated with a decrease in frequency rather than any change in intensity. The role of atmospheric indices on affecting deficits, precipitation, and potential evapotranspiration was explored. In particular, the Bermuda High and PNA indices show the strongest correlations with soil-moisture deficits during the warm season. |
