Beyond one-size-fits-all: a path toward region-specific flash drought monitoring and management

Flash droughts are characterized by the rapid onset and intensification of drought conditions, yet the lack of a standardized definition and detection method makes them particularly difficult to anticipate and manage. We compare six commonly used indicators (evaporative, soil moisture, precipitation, and multicriteria-based indicators) across all contiguous US catchments over a 40 year period, producing the first comprehensive catchment-scale database of flash drought events nationwide. Detection proves highly inconsistent, with substantial variation in the number of events identified and limited agreement between indicators—even among those based on similar variables, with agreement ranging from 12% to 70%. A multi-indicator approach can improve robustness but risks underdetection if overly strict, while reliance on a single indicator may lead to false positives. Case studies in Montana (2017) and Connecticut (2022) underscore the importance of aligning indicators with regional climate conditions and water-use sectors. Our findings demonstrate that effective flash drought monitoring requires moving beyond one-size-fits-all definitions and toward region- and sector-specific approaches, validated against real-world impacts, to support early warning systems and adaptive management.