Abstract:The evolution characteristics of “16.7” extremely torrential rain in Shijiazhuang is analyzed using multi-source observation data such as wind profile radar, ground GPS water vapour, microwave radiometer, weather radar, satellite cloud, lightning location and ground intensive automatic weather stations. The results show that: (1) High-value stage of total water vapour by ground-based GPS and microwave radiometer was parallel with the heavy precipitation stage. The entire water vapour was positively related to the precipitation intensity. The total water vapour content increased significantly before the beginning of precipitation, and the sudden increase of total water vapour had a hint effect on the beginning time of precipitation. The high-value time was 5 hours ahead of the starting time of precipitation. (2) The thickness and intensity of east wind in the low layer positively correlated with heavy precipitation. The wind direction of the lower layer turned to the northwest wind, indicating the end of the heavy rainfall. The emergence time of low-level jet was 5 hours earlier than the beginning time of precipitation, and the dissipation time of low-level jet was 3 hours earlier than the end time of precipitation. When its wind speed was more than 20 m·s-1, the east wind jet had a certain indication effect on the heavy precipitation. The strong rainfall corresponded to the decrease of the minimum height of low-level jet and the increase of the maximum wind speed at the lower level, which was the peak area of the low-level jet index and vertical wind shear of 0-3 km. (3) The process was more stable, and the weak lightning and thunderstorm only occurred on the 19th. Radar echo and satellite cloud showed this precipitation of mixed clouds, including large-scale stratiform cloud and cumulus cloud. The centroid of echo was low, and the training effect was obvious. It belongs to the type of tropical precipitation. The minimum of TBB was -55 ℃. The maximum reflectivity factor, vertical cumulative liquid water content, and echo top were 55 dBz, 15 kg·m-2, and 11 km, respectively, obviously related to precipitation. The large value area or velocity ambiguity appeared in the radial velocity fields.