Change Features of GPS/MET Precipitable Water Vapor in Different Precipitation in Lianyungang

Based on the GPS/MET water vapor monitoring data and conventional meteorological data at Lianyungang station from April to July,2015,the relationship between precipitable water vapor and real precipitation was studied. According to different precipitation,change trends of precipitable water vapor in convective precipitation and steady precipitation were analyzed. Results showed that necessary condition of precipitation generation was high precipitable water vapor value in the air. Precipitable water vapor change presented wave-shape and phased characters. In convection precipitation,precipitable water vapor changed frequently and had larger change amplitude,while its change was slow in steady precipitation. The appearing time of the maximum values of rainfall intensity and precipitable water vapor was not necessarily consistent,but it was known that severe rainfall usually began at the high-value stage of precipitable water vapor,and high-value stage of precipitable water vapor often corresponded to higher precipitation probability. In addition,precipitable water vapor showed different characteristics in the above two different precipitation,and these results could provide a reference for precipitation forecast.