A Method of Building Vertical Wind Shear Feature and Convective Storms Recognition Based on This Feature

Abstract

There is a very close relation between severe convective storms and vertical wind shear. Therefore, it is particularly important to extract the vertical wind shear feature used to recognize storms and distinguish the type of storms such as rainstorm, hail with small or large scale. In meteorology, Doppler radar echo images are used to detect storms, which are reflectivity images(RI) and radial velocity images(RVI). This paper delineates probable storms firstly in RI with low elevation angles, then raises gradually the elevation angle to calculate radial wind shear in RVI point by point and generate a feature called the Vertical Shear Factor(VSF). A lot of testing show that the VSF's difference between rainstorm and large hail is very marked and only by this feature the radio of distinguishing rainstorms from large hails can be increased closely 5∼10 times than reflectivity strength usually used by weathermen.