Hydrometeorological analysis of a flash flood event in an ungauged Mediterranean watershed under an operational forecasting and monitoring context

The current study presents the first attempt to investigate November 2019 catastrophic flash flood in Olympiada (North Greece) under an operational forecasting and monitoring context, based on mesoscale weather research (WRF) model integrated multi-satellite retrievals for global precipitation measurement (GPM-IMERG) algorithm. When evaluated against ground-based rainfall measurements, WRF showed adequate predictive capability concerning severity of observed rainfall, even though model's performance suffered from phase spatial displacement errors. GPM-IMERG algorithm yielded best capturing timing excessive rainfall. Concerning hydrological outcome using Hydrologic Engineering Center-Hydrologic Modelling System (HEC-HMS), a strong indication forthcoming could have been provided at least 2 days advance WRF-based HEC-HMS-simulated peak (139.3 m3 s−1), as it was close drainage capacity constructed bridge plain stream bed, 100-year return period discharge.