A Southeastern US Regional Flash Drought Review and Agriculture Impact Assessment

The Southeast US (SE) has experienced several drought episodes since 2000 and is particularly susceptible to rapid onset of short-term droughts (flash droughts). In the SE, the surface-based hydrologic cycle is accelerated relative to other regions due to consumptive vegetation and generally poor water-holding soils. The impacts may be widespread and often bring catastrophic consequences for a variety of sectors, most acutely, agriculture. There is a need to better characterize flash droughts in the SE with specific focus on the onset, timing, duration, and impacts. Here we present an assessment of flash drought events across the southeast providing a spatial and temporal review of rapid onset drought metrics across the SE using regionally derived datasets to compare characteristics such as timing, antecedent conditions, impacts, and amelioration. This study utilizes the Lawn and Garden Moisture Index (LGI), the Evaporative Stress Index (ESI), and the Soil Moisture Volatility Index (SMVI) (via modeled and in situ data) in comparison with the United States Drought Monitor (USDM). Results include flash drought occurrence and vulnerability by season and county across the SE and will provide insights on how these events translate to agricultural risks in the region.