A MESO-scale Rain gauge NETwork-MESONET over Mumbai: Preliminary results and applications

Mumbai, the compact megacity, the economic capital of India, is highly vulnerable to severe weather conditions, particularly related to the rainfall phenomenon. A MESO-scale rain gauge NETwork (MESONET) comprises 131 rain gauges scattered over the Mumbai metropolitan region is established to have instantaneous rainfall information. A real-time web-based rainfall data portal is set up as a public informative/awareness system that would help the public to cope with unanticipated situations caused by massive rainfall events. In this work, we provide the rationale of Mumbai MESONET and preliminary results from the observations during July–October 2019. High-resolution MESONET rainfall data are analyzed to examine the mean and associated small-scale spatiotemporal variability of rainfall over Mumbai. The results depict that the maximum contribution of rainfall is from low to moderate and heavy rainfall events. The prevalent occurrence of prolonged rainfall events of moderate to high intensity during mid-night and early morning hours is attributed to the diurnal variability of events duration. It is observed that heavy rainfall events (64–124 mm/day) occur at a sub-daily scale. Correlogram analysis of rainfall further reveals the good spatial coherence in the spatial variability of rainfall even at sub-daily scales. •A dense rain gauge network (MESONET) established over Mumbai and surrounding regions.•Event duration analysis shows that heavy rainfall peaks in the midnight, early morning.•Strong spatial coherence in rainfall is noticed in harmonic and correlogram analysis.•Real-time data from MESONET helped to monitor the evolving state of rainfall systems.•MESONET has potential applications such as for flash flood forecasting.