This study investigates the primary dynamic forcing factors and sources of water vapor influencing remote heavy rainfall over North China,generated by Typhoon Lekima on August 10,2019.We utilize surface rain gauge data,ERA5 reanalysis data,and ECWMF ensemble forecast data.Ensemble sensitivity analysis reveals that low-level relative vorticity over the remote typhoon precipitation (TRP) area plays a pivotal role as the most significant dynamic factor facilitating TRP.The intensification of low-level relative vorticity closely correlates with the strengthening northerly winds in the northern region,induced by the deepening of the low-level short-wave trough.These winds are jointly related to the reinforcement of low-level southerly winds between the TRP and typhoon precipitation (TP) areas.The divergence term of relative vorticity emerges as the crucial dynamic process governing the periods of TRP strengthening and weakening.During the phase of TRP enhancement,positive vorticity is primarily attributed to positive divergence,while negative divergence leads to the reduction of relative vorticity and the weakening of TRP intensity.At 500 hPa,water vapor in the TRP region mainly originates from the local area and Typhoon Lekima,while 60％ of the water vapor at 700 hPa is sourced from Typhoon Lekima.At 850 hPa,40％ of the water vapor is contributed by Typhoon Rosa,with the remaining 60％ of water vapor being transported from Typhoon Lekima and the local area.