Abstract:By using conventional observation data, the causes of the formation of low-temperature, rainy and snowy weather process in Jiujiang City from January 25 to 28, 2018 are analyzed. The circulation characteristics and evolution of continuous low-temperature, rainy and snowy weather in Jiujiang City are pointed out. The application indexes of vertical temperature stratification characteristics of freezing rain in Jiangxi Province are summarized. The results show that the location of snowfall area corresponds to the convergence area of 850 hPa-925 hPa under the stable circulation situation of 500 hPa and 700 hPa; active water vapor transport and strong convergence can maintain the rain and snow weather; low-level cold air plays a key role in the phase of winter precipitation; the occurrence of frozen rain in Jiangxi Province is usually accompanied by severe 1000-850 hPa cooling and 700 hPa warming, 925-700 hPa warming. There is obvious temperature inversion. The thawing layer is the necessary condition for the occurrence of freezing rain. The thawing layer of freezing rain is located at 700 hPa. Generally, the temperature of 1000 hPa < 1 C, 925 hPa and 850 hPa < 2 C and 700 hPa < 0 C are used as the threshold criteria for the prediction of freezing rain in Jiujiang. At the same time, attention should be paid to the situation that the thawing layer is located at 850 hPa. The lower the surface temperature is, the better the formation of frozen rain. The lowest temperature is below 0 and the average temperature is below 1.0 when the frozen rain occurs.