Radars-gauge (dis-)agreement during the 1994 Piedmont flood

A comparison of precipitation amounts as measured by a network of gauges and two different radar systems is presented (an “old-generation” non-Doppler radar and a “new-generation” Doppler one). In spite of their different technology, the two radars share very similar conditions, namely: adverse orography, good view of the area of interest from the radar sites (implying severe ground clutter contamination), and large radar-gauge distances. The available radar data consist of maximum reflectivity echoes maps. The agreement between the different measurement systems is characterized in terms of correlation coefficients between radar-gauge data pairs. The analysis confirms that the spatial representativeness of gauge measurements increases with increasing integration period (although limited, of course, by the relatively short flood duration)