Nbou, M. (CNCRM Engineer, Direction de la Meteorologie Nationale, Casablanca, Maroc)
Moroccan Meteo office is undergoing an extensive modernisation program intended especially to improve its Very Short Range Forecast including nowcasting. This nowcasting program is primarily based on the Doppler Radars Network. Since the end of 1995, the Meteo office is equipped of an operational weather radars network, which meets some forecasters and hydrologicals need. The goals of this network are the detection and the identification, in real time, of sever storms related to convective situations, the instantaneous evaluation of the spatial repartition of the precipitations.
This network is built around five new generation C band Doppler radars (DWSR-92C). The radars are installed at Agadir, Casablanca, Larache, Khouribga and Fes. The radar installed at Fes includes a dual linear polarization (ZDR technique) which is useful to detect hail (frequent in this region).
The radars placement permits to covers a big portion of the northern part of the country. A spatial resolution of the radars less than 200 km causes an important overlapping between the scanned areas. This latest point has two advantages. It permit to minimize the problems related to the C bands attenuation and blind areas near the radars. It further opens new perspectives to the development, mainly in the radars inter-calibration and the vertical velocity estimation.
The scanning strategy consists mainly on a volume scan of ten (10) elevations in less than ten (10) minutes. The radars data are transmitted to the central site where a composite picture is made every ten (10) minutes, and stored for our future developments.
The goal of this paper is to give an idea about the technical aspects of Moroccan Weather Radars Network and the oprating strategy used.