Atmospheric moisture linkages to flood inducing Multiday extreme precipitation in India

Extreme precipitation events are becoming more frequent and intense worldwide, significantly elevating the risk of devastating floods. India, as a hydrologically vulnerable region, experienced recurrent floods that lead to substantial economic losses and fatalities. This study explores the atmospheric drivers and moisture linkages responsible for multi-day extreme precipitation events that resulted in meteorological floods across India. Severe meteorological flood events were identified across India using the Dartmouth Flood Observatory (DFO) database. The study examines the interplay between Integrated Vapor Transport (IVT) & Integrated Water Vapor (IWV) at different vertical layers of the atmosphere, and precipitation at hourly timescales. Results highlight the critical role of elevated moisture transport in the lower atmosphere, which intensifies prior to flood events. Spatial analysis reveals a strong correspondence between IWV and precipitation patterns, suggesting that IWV provides a more consistent spatial signal for extreme precipitation events than IVT. The findings indicate that sustained moisture influx alone is insufficient to trigger extreme precipitation. However, its interaction with local atmospheric instability and synoptic-scale disturbances creates a conducive environment for prolonged precipitation, culminating in floods. This study underscores the importance of atmospheric moisture dynamics in driving extreme precipitation events and calls for deeper investigation into regional moisture budgets to improve flood prediction and mitigation strategies. 

Keywords: Meteorological floods, Atmospheric moisture transport, Multi-day extreme precipitation, Flood drivers.