The dynamic forecast method of convective vorticity vector

Abstract

In this paper we introduce the convective vorticity vector and its application in the forecast and diagnosis of rainstorm. Convective vorticity vector is a parameter of vector field, different from scalar field, it contains more important information of physical quantities, so it could not be replaced. Considering the irresistible importance of vector field we will introduce the theory of vector field and its dynamic forecast method. With the convective vorticity vector and its vertical component's tendency equation, diagnostic analysis on the heavy-rainfall event caused by landfall typhoon “Morakot” in the year 2009 is conducted. The result shows that, the abnormal values of convective vorticity vector always changes with the development of the observed precipitation region, and their horizontal distribution is quite similar. Analysis reveals a certain correspondence between the convective vorticity vector and the observed 6-h accumulated surface rainfall, they are significantly related. The convective vorticity vector is capable of describing the typical vertical structure of dynamical and thermodynamic fields of precipitation system, so it is closely related to the occurrence and development of precipitation system and could have certain relation with the surface rainfall regions.