Radar characteristics associated with the straight line wind from western Romania - September 17th 2017.

Abstract

The present paper is a radar analysis on the mesoscale convective system (MCS), which evolved as a straight line wind across western Romania in the afternoon of the September17th. This convective storm has developed in a SV-NE oriented baro-cline area, extending from the Italian Peninsula, over Serbia, Hungary, Poland and Ukraine. The temperature gradient was over 15 degrees, and the tropospheric jet was parallel to this baro-cline. Large wind velocities were present throughout the troposphere column, which means that the shear force had high values throughout the tropospheric column, but concentrated to 500 hPa (approximately 5500 m) and in the low layers below 700 hPa (approximately 3000 m), saturation deficit was high on the western border of Romania. All these elements initiated and organized the thermo-dynamic convection towards a severe structure. The storm was initiated by the strong descending of the convective meso-scale system that evolved over the northwest of the Balkan Peninsula (Croatia and Bosnia).

Keywords

• radar analysis
• drecho
• severe wind storm