Numerical Simulation and Diagnostic Analysis of a Yangtze and Huaihe River Shear-line Heavy Rainfall Event
Abstract：By using the non-hydrostatic meso-scale model WRFV3.3, a shear-line heavy rainfall e- vent over Yangtze and Huaihe River basin during 12--13 July 2010 is numerical simulated. The large scale circulation condition, meso-scale cyclone development and the relationship between VDI （interac- tion index of vortex and deformation field） and rainfall are analyzed. It is shown that the shear-line heavy rainfall process occurs under the influences of the stable 200 hPa South Asia high, 500 hPa eastward short wave trough and western Pacific subtropical high, 700 hPa and 850 hPa meso-seale cyclones, and the perturbations of Meiyu front. WRFV3.3 is well simulated the rainbands and rainstorm center of rain- storm process. Meso-scale cyclones occurred within the northeast-southwest orientated shear line over middle and lower reaches of Yangtze River, while heavy rainfall occurred to the south of the shear line and to the left of the low-level jet （LLJ）. The large wind speed center of LLJ is well corresponding to the 1 h rain intensity. There is significant correlation between meso-scale vortex and large wind speed center, the stronger wind speed is, the stronger vortex becomes. The VDI is well directed the precipitation center and intensity, which is help to make the right judgment in the actual forecast.
Keywords：heavy rainfallshear linemeso-scale vortexnumerical simulationVDI
Publication Date：2012-05-26
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 17-25 )