Numerical Simulation of a Convectional Weather Process in Guyuan of Ningxia Based on WRF Model

Based on the NCEP reanalysis data with 1° × 1° spatial resolution,the strong convective weather which occurred in Guyuan of Ningxia on July 14,2007 was simulated by Weather Research and Forecasting( WRF) model,and the circulation situation,physical quantity field distribution and radar echo characteristic of the strong convective weather were summarized. The results showed that the precipitation simulated by WRF was bigger than the observation of radar,and the location was southeastward. The configuration of high level divergence and low level convergence,andtrumpetsounding curve were comparatively consistent with the precipitation area. Graupel and snow were the main source of rain water,while cloud water is the main source of graupel and snow growth. The number concentrations of cloud droplet had an important impact on precipitation of convective cloud. When number concentration of cloud drops increased,the early precipitation and its range reduced,while the later precipitation and its range increased. In addition,the number concentrations of cloud drop also had important effect on the distribution of mixture of cloud water,rain water,ice crystal,snow and graupel. When the number concentration increased,the content of cloud water increased,the early content of rain water,ice crystal and graupel decreased,but the later increased.