A Southeastern US Regional Flash Drought Review and Agricultural Impact Assessment

The Southeast US (SE) is particularly vulnerable to flash droughts—rapidly developing, short-term droughts—due to consumptive vegetation and poor water retention in soils. These events can have significant impacts, especially on agriculture. This study evaluates flash droughts in the SE, focusing on their onset, duration, and impacts using metrics such as the Lawn and Garden Moisture Index (LGI), Evaporative Stress Index (ESI), and Soil Moisture Variability Index (SMVI), alongside the U.S. Drought Monitor (USDM). A key insight from this study is the importance of flash drought timing in relation to critical agricultural growth stages. Flash droughts that coincide with crucial growth phases can sharply reduce crop yields, as crops are particularly sensitive to moisture deficits during these periods. Here we identify not only the risk but also the vulnerability of crops to flash droughts, highlighting how the timing of these events can exacerbate agricultural impacts in the region. This assessment underscores the need to better understand how the timing of flash droughts influences agricultural outcomes across the region.