摘要
By using the ground,high-altitude conventional observation data and NCEP global reanalysis data,the circulation background and the snowfall causes of light rain changing to snowstorm weather process in Panjin during February 12-13 in 2009 were analyzed in detail.Focusing on the rain and snow phase state conversion time,the effects of precipitation phase state transformation time on this precipitation forecast were discussed.The results showed that the circulation adjustment,the eastward shift and down south of polar vortex and the frequent activity of cold air were the main factors which caused the precipitation was obviously more in February in Panjin.The direct reasons which caused the strong snowfall in Panjin were that the warm and cold air evenly matched for a long time,and the southwest jet provided the sufficient water vapor condition.
By using the ground,high-altitude conventional observation data and NCEP global reanalysis data,the circulation background and the snowfall causes of light rain changing to snowstorm weather process in Panjin during February 12-13 in 2009 were analyzed in detail.Focusing on the rain and snow phase state conversion time,the effects of precipitation phase state transformation time on this precipitation forecast were discussed.The results showed that the circulation adjustment,the eastward shift and down south of polar vortex and the frequent activity of cold air were the main factors which caused the precipitation was obviously more in February in Panjin.The direct reasons which caused the strong snowfall in Panjin were that the warm and cold air evenly matched for a long time,and the southwest jet provided the sufficient water vapor condition.
