Role of Arabian Sea warm pool and atmospheric instability in triggering a monsoonal MCC over Peninsular India

Mesoscale Convective Complexes (MCCs) significantly contribute to the global hydrological cycle and about 50% of the total monsoon rainfall over the Indian region through extreme rainfall and flood events. An extreme rainfall event triggered devastating landslides and widespread damage over Wayanad in the Western Ghats, India, during 29-30 July 2024. This study investigates the MCC responsible for the event using satellite, in-situ, and reanalysis datasets. The system exhibited deep organized convection, strong low-level moisture transport, and upper-level divergence within a highly unstable atmospheric environment. An anomalously persistent warm pool over the southeastern Arabian Sea, sustained during a monsoon break phase, created favorable thermodynamic conditions through elevated sea surface temperatures and latent heat fluxes. The findings underscore the growing role of ocean-atmosphere coupling in monsoonal convective extremes and highlight the need for improved mesoscale modeling and early warning frameworks over topographically complex regions like the Western Ghats.