Date of this Version
This study examines the spatial evolution of drought severity within the contiguous United States during the first six months of average Great Plains-centered drought events. It identifies Great Plains-centered drought events from 1895-1989 based on the drought history of the North Central, South Dakota and Low Rolling Plains, Texas climatic divisions. Time series of warm- and cold-season average drought severity based on Great Plains drought for all United States' climatic divisions are calculated and spatially analyzed.
Mapped patterns show spatial teleconnections in drought development. Cold-season drought patterns based on the North Central, South Dakota climatic division are clearly in-phase with droughts in the lower Mississippi Valley. Drought patterns based on the Low Rolling Plains, Texas climatic division reveal that droughts are in-phase across the southwestern United States, but are largely out-of-phase with the eastern states.