Overview of the Greater Lyon weather radar advances from 90's to 2008

Abstract. The local weather radar of Lyon, part of the Aramis network of Meteo-France, is currently located 40 km from the urban community. The measurement quality of this tool is subjected to constant improvements from Meteo-France. Indeed, its hydrological measurement quality has steadily evolved from the early 90's until today. This article, therefore, proposes a return on these innovations, assessing measurement quality over the territory of Greater Lyon. This study is based on two successive radar locations, and also on raw reflectivity data and on rain accumulation over the past 15 min (Hydram) or 5 min (Panthere). The measurement performed on the site Satolas was unsatisfactory because of too many ground clutters; and therefore the radar was moved to Saint-Nizier. This new location associated with radar Hydram rain accumulation has reduced the problem of ground clutters. These rain accumulation data have given correct results in comparison with local data of the raingauge network of Greater Lyon, after a global and spatially uniform correction, based on these gauges. The latest generation of radar rain accumulation (Panthere) has, nearly completely, eliminated the problem of ground clutter in the urban area and provides very satisfactory measurements, especially during intense rain events.