Water vapor imageries superimposed with upper-level dynamical fields can potentially provide valuable information for operational forecasting. A joint interpretation of a cold vortex related severe convection in Shandong Province is conducted by employing water vapor imagery and upper-level dynamic fields. Results reveal that the cloud system of the cold vortex exhibited asymmetric structure. Mechanism of instability growth varied between the warm and moist convection in the southeast and the convection out broke in the dynamic dry band at the rear of the vortex. As the dynamic dry band at the rear of the cold vortex overrunning the warm and moist area at the lower levels of the troposphere, deep convection was induced. Water vapor imageries closely mirror the upper-level synoptic-scale forcing during different developing stages of the cold vortex. The pronounced darkening of the dynamic dry band combined with sharpening of the dark/light boundary is associated with the strengthening of high potential vorticity and the upper-level jet. Monitoring a sequence of water vapor imageries helps in identifying and following the upper-level dynamic forcing, and provides valuable information of upper-level dynamic fields in diagnosing deep convection environment.