The Diagnostic Analysis And Numerical Simulation Of A Cold Vortex Heavy Rain

By analyzing the synoptic situation and the physics quantity fields of the heavy rain process occurred in August 2000 in Hebei Provence,the formation of this process is discussed.Study shows that the process is caused by cold vortex in the east of Mongolia and subtropical high,and meso-scale convective cloud cluster is the direct reason of the local severe heavy rainfall.The precipitation area has a good relationships with low level positive vorticity, water vapor, pressure energy,moist enthalpy,potential vorticity etc.MM5. model is used in this paper to simulate the formation of meso-scale convective cloud cluster and the effects of terrian , southeast wind of low levels on this heavy rainfall process and draw the conclusion that there is a rapid accumulation of energy before meso-scale system takes shape and the precipitation of this process is greatly effected by the mountain over west and north parts of North China.when the terrian is removed,the location and intensity of the heavy rainfall would be changed Iargely.If the low level southeast wind is wekened the speed of movement and the intensity of cold vortex in the east of Mongolia are changed in different degree and the lower the level is ,the more obvious.the effect is.