Evaluation of the new operational French radar product for urban hydrology

The main objective of this paper is to evaluate, for urban scales, the quality of the new French operational radar processing chain developed by Meteo France. This product is deployed within the French operational radar network. The evaluation is done by comparing radar data (1 km² resolution) to rain gauge data at four different time scales i.e. 5, 15, 30 and 60 min. Radar data is given by the radar of Trappes located 30 km south-west of Paris. 87 rain gauges located from 0 to 135 km around the weather radar provide the ground reference data. The data set consists in 50 varied rainy days. The influence of the distance, of the quality of the radar data and of the rain type as well as of the adjustment factor is analysed. The present analysis finally tries to evaluate the error peculiar to the reference data by considering instrumental and representativeness errors in order to take into account the accuracy of the reference data in the radar/rain gauge comparison.