A Changjiang-Huaihe cyclone, which occurred during 5-8 November 2015, is characterized by its later occurrence, northern location and northeastward-to-southeastward turning track. This cyclone led to heavy rains for 36 hours over Shandong Peninsula with maximum cumulative precipitation near 50 mm. Synoptic analysis of the cyclone is carried out in this study using the Final Analysis Data of Global Forecast System (FNL). It is revealed that the western Pacific subtropical high (WPSH), which is abnormally stronger and northern located, accounts for the cyclones late occurrence and northern location, and that the anomalies of the WPSH are closely related to the strong El Nino event in 2015. To reveal the mechanism of the northeastward-to-southeastward track turning, a series of numerical experiments were conducted using the WRF (Weather Research and Forecasting) model. It is found that: 1) High sea surface temperature (SST) of the Yellow Sea (YS) is favorite for upward transportation of water vapor flux, which enhances the cumulus convections, and intensifies cyclone by latent heat release. The southwesterly steering flow has little influence on the track of the intensified cyclone, which keep moving northward and turns southward midway. 2) Another important factor contributing to the track turning is the existence of the energy front over the YS, which is generated by the large SST gradient (SST in the southern YS is about 4 degrees higher than that in the northern YS). In addition, the north winds in the low and middle troposphere and the withdrawing of the WPSH also help the cyclone turn southward.