Abstract:

In order to accurately forecast the first soaking rain during the spring sowing period, and better serve three rural, the author analyzed the first soaking rain, which occurred on May 8th-10th, 2011, from the high altitude circulation background, the middle-lower altitude impact system, the surface pressure field characteristics and the space-time evolution characteristics of physical field (relative humidity, divergence, vertical velocity, vorticity) space vertical profile and the fy-2c satellite cloud picture. The results showed that the first large-scale soaking rain took 500 hPa stable subtropical high and westerly trough as background; The main influence system were 700 hpa shear and precipitation cloud system creation, intensity change, movement; During precipitation, the ground pressure field were located in the high pressure south and controlled by easterly flow; The time-space change of physical field vertical profile showed the character of deep wet lay, flow configuration of low-level convergence and high-level divergence and strong vertical ascending motion, these were the favorable conditions of spring-sowing soaking rain.