一次高原强降水过程的对流尺度集合预报试验及诊断分析OACSTPCD

The GPM(Global Precipitation Measurement)satellite data and ERA5(ECMWF Reanalysis v5)were used to perform ensemble forecast simulation,evaluation and diagnostic analysis on a severe precipitation event that occurred in the southwest plateau region of China on May 9-10,2014.Results found that the WRF model successfully reproduces the severe precipitation event,and the ensemble average forecast generated using the BGM(Breeding Growth Mode)and LBGM(Local Breeding Growth Mode)initial perturbation methods had better forecast accuracy than the control forecast,with the LBGM evaluation producing better results.The severe precipitation area was located in a region of high atmospheric moisture divergence and low-level convergence,and the distribution of negative vertical vorticity and positive vertical vorticity in the upper and lower levels of the atmosphere corresponded to the precipitation area.The study also identified the positive and tilted pressure of wet potential vorticity as having a certain indicative significance for severe precipitation,with the negative MPV1 region at 850 hPa and the positive MPV2 region corresponding well with the precipitation band and intensity development.The LBGM scheme exhibits superior improvement in rainfall intensity compared to the BGM scheme,primarily due to the more realistic simulation of water vapor flux divergence and vorticity in the LBGM scheme.