Characteristic Analysis of Doppler Radar About a Hailstone Severe Storm

doi:10.3969/j.issn.1673-7148.2012.03.001

Abstract：We studied a local convective weather occurred in the central north region on 9 July 2007, during which short-time rainstorm, local hailstone and short-time heavy wind were all happed, with the NCEP reanalysis data and Doppler weather radar products of Beijing and Tianjin. Analysis showed the tilted trough became forward from backward, and stratification became more judder on bottom layer, in this context the shear line of wind near ground was the condition of the storm growing. Some a- nalysis of physical quantity showed information including： the moisture convergence had spread from ground to 850 hPa before rain but it was shallower; convergence of lower layer and divergence of higher layer strengthened vertical motion; the storm occurred in the area of the strongest vertical motion. Based on the Doppler weather radar products, we distinguished that the storm had characteristic of mesocyclone and similar heavy precipitation supercell; the accuracy rating about storm tracking information was related to numbers and different movements of all storms; there were some deviations between actual direction of storm and the forecasting route of radar, its total variation was between 29--67 °, but the storm tracking information still had certainly indicative helpfulness on short-range prediction; the wind-profiling product emerged perpendicular wind shear spin round on clock-wise between 3--7 km high level, on this helpful condition the storm maybe developed and became heavy precipitation supercell.