WEATHER RADAR VELOCITY FIELD CONFIGURATIONS ASSOCIATED WITH SEVERE WEATHER SITUATIONS THAT OCCUR IN SOUTH-EASTERN ROMANIA

摘要

In the present study, the analysis of the Doppler radial velocity field obtained with the weather radar operational at Medgidia (SE Romania) is performed. This was made in order to characterize the severe weather situations that occurred during the convective seasons (May-September) of the years 2003-2007. The radial velocities were measured at 3.4° elevation of the radar antenna. The measurements at this particular elevation were chosen because they highlight better the tropospheric flow. An average over 24 hours of the velocity field for the days with severe convection was performed, emphasizing the vertical wind shear and the tropospheric jets. Averaged Doppler velocity fields were divided into classes (configurations) depending on the direction of tropospheric flow and on the vertical shear. For each configuration, a characteristic velocity field that reveals the intensity of the tropospheric flow was emphasized. Each configuration of velocity field is associated to various characteristics of severe convective cells.