The HydroMet Decision Support System: operational applications in hydrology and flash flood prediction

Weather Decision Technologies (WDT) in collaboration with the National Severe Storms Laboratory (NSSL) in the US, and the Regional Agency for Environmental Protection and Prevention of Veneto (ARPAV) in Northern Italy has developed a turn-key hydro-meteorological package termed the HydroMet Decision Support System (HDSS). This system integrates data from radars, rain gauges, satellites and numerical models to provide high resolution Quantitative Precipitation Estimates (QPE) and Quantitative Precipitation Forecasts (QPF).

HDSS includes the following components: 1. radar quality control including clutter removal, bright-band identification, hybrid scans, and scan filling 2. mosaicking of two radars in the Veneto region 3. processing of the data using a package called Quantitative Precipitation Estimation and Segregation Using Multiple Sensors (QPE-SUMS) for the derivation of QPE fields 4. forecast of radar reflectivity fields out to 3 hours using the McGill Algorithm for Nowcasting Precipitation Using Semi-Lagrangian Extrapolation (MAPLE) 5. derivation of QPF fields using the results of MAPLE 6. derivation of combined QPE and QPF amounts for delineated basins over the Veneto region 7. a Flash Flood Prediction Algorithm (FFPA) which checks QPE and QPF amounts of each basin against user defined Flash Flood Guidance (FFG) values 8. automated alerting of basins that are, or are forecast to, approach or exceed FFG values

Data and product outputs are available via customized Web pages and a three-dimensional graphical workstation.

This paper will discuss the components of the HDSS with specific emphasis on the operational use of the system for flash flood forecasting. Results of cases to date will also be presented.