Abstract: Based on the perceptible water vapor (PWV) data from the ground based GPS, the water vapor characteristics of precipitation weather processes in Dalian in 2010 were analyzed. The results show that the PWV data could reflect the temporal and spatial variation of water vapor and its variation characteristics has a significant corresponding relationship with precipitation. If the precipitation process differs, the PWV characteristics are also distinctly different. The PWV variation is gentle for a stable precipitation type and it has a single peak value; water vapor changes violently for a convective precipitation type and it is in a fluctuating trend; it is of the common characteristics of the above two precipitation types for a mixed precipitation type. The thresholds of the PWV related to rain are also given in the text, which indicates that the PWV data are useful to forecast precipitation to some extent.

Key words: Precipitable water vapor (PWV), Stable precipitation, Convective precipitation, Mixed precipitation