Annual Seminar 2022

During midday on 20 April 2022, excessive rainfall and associated flash flooding across the Forish District in Uzbekistan resulted in five fatalities and extensive damage in the area. According to the media, an exceptional amount of rain fell over two hours in five local streams and the surrounding hillside caused the water to gush rapidly down the slopes into the village of Egizbuloq in the Forish District which experienced one of the destructive events with the return period of 50 years. In general, rainfall amounts exceeding 15 mm within 12 hours is a lower threshold for precipitation-induced natural hazards in the local area. However, during the rainstorm, an official 2 hourly total rainfall of 31.5 mm was recorded near the town of Gallaorol (about 100 km southeast of Forish District center), and daily accumulated rainfall up to 80 mm was estimated by satellite observations of the Global Precipitation Measurement (GPM) over the area. The objectives of this study are to describe convective-scale processes and the synoptic environment responsible for initiating and maintaining the Forish flash flood (i), to apply the point-based ecPoint Rainfall technique for estimating convective rainfall from European Centre for Medium-range Weather Forecasts (ECMWF) operational analysis data (ii), and to address the question of how unusual the convective-scale flow configuration and precipitation characteristics were in the context of meteorological analysis and operational response. Although further targeted experiments are needed, this study provides strong indications to identify the critical role of convective precipitation-induced natural hazards and to develop predictions of flash floods and debris flow occurrences in the region.