Analyzing the low level atmospheric convergence characteristics in the short-time heavy precipitation using average divergence products retrieved from weather radar

Using the averaged divergence retrieval data based on Hubei new generation weather radar, combined with upper, surface and radar observation data, the evolution characteristics of the low level convergence in short-time heavy precipitation was analyzed. The warning significance was tested and the synoptic significance of low level convergence was explained. The results show that the evolution of low level convergence had the structural characteristics of single trough or double trough with the obvious mesoscale feature. In the early stage of heavy precipitation, the low level divergence is convergent or divergent to convergent. The low level convergence develops to the strongest stage in the concentration stage, then weakens gradually. At later stage, the low level convergence turns to divergence. The low level convergence and obvious enhancement may have the significance of early warning. Thunderstorm cold outflow and low-level jet reinforcement have important contributions to the low level convergence.