Title: Regional Characteristics of Flash Droughts Across the United States
Flash droughts are characterized by the rapid onset and development of drought conditions. When a combination of extreme atmospheric anomalies (such as lack of rainfall, higher surface temperatures, higher surface wind speeds, and higher vapor pressure deficient) persist for several weeks, rapid depletion of soil moisture will occur and lead to a large increase in evaporative stress on the environment. As a result, flash droughts can have significant impact on short-term water resources and lead to large agricultural yield loss in the growing season.
The Standardized Evaporative Stress Ratio (SESR) is used to identify flash drought events across the CONUS from 38 years of data from the North American Regional Reanalysis. The utility of SESR is explored by examining the spatial evolution of the 2012 flash drought event that occurred across the central Great Plains and Midwest. Furthermore, regional characteristics of rapid drought intensification were quantified by examining the temporal hotspots of flash droughts, the timing of peak intensity (rate of intensification) during the growing season, the preceding moisture conditions before the rapid onset and development of drought, and the percentage of flash droughts that transitioned to longer term drought.