Abstract:By using the conventional meteorological data, infrared cloud images of th FY4A satellite and doppler meteorological radar data, this paper analyzes a severe convective weather case occurred on 17 May 2019 in the central BeijingTianjinHebei region, accompanied by a strong hail, shortterm heavy precipitation and shortterm strong winds. To further reveal the environmental conditions of the convective storm formation and the mechanism of backward propagation, the Variational Doppler Radar Analysis System (VDRAS) and meteorological data of a national automatic weather station are used. The results show that under the largescale background field being favorable for the occurrence and development of strong convection, the convection system around the central BeijingTianjinHebei region developed rapidly. The convection system was triggered by a southward moving ground convergence line at the BeijingLangfang border, which was the confluent area between the southeast air flow from the Bohai Bay and the strong northeast cold air flow generated by the cold pool formed by the strong convection weather in the BeijingTianjin region earlier. It is shown as a backwardpropagating multicell storm. The main reasons for the backwardpropagation are the strong wind shear in lower atmosphere (0 to 3 km) and the positive feedback effect between new and old storm cells.