Abstract:Using the Global Forecast System (GFS) analysis data from the National Centers for Environmental Prediction (NCEP), the synoptic feature was analyzed for a snowstorm occurred in Southeast Hubei from January 15 to 16, 2007. The mesoscale model of Weather Research and Forecasting (WRF) was used to forecast this snowstorm and the mechanism of the snowstorm was analyzed. The large-scale circulation shows that the snowfall resulted from the southwest jet at 700 hPa in conjunction with cold air on the surface. Snowstorm processes were highly associated with the movement of the southwest jet. The WRF model can simulate well the snowstorm. The results show that the onset and end of the precipitation corresponded to the movement of the southwest jet. In the left side of southwesterly jet, it is the increased low level vorticity that caused low-level convergence and high-level divergence ,then caused ascending motion to strengthen, therefore, the snowstorm occurred.Furthermore,the results showed the difference of the vertical motion between heavy rain and blizzard.