A turbulent gaseous jet in crossflow with velocities comparable to the real gas turbine condition is numerically investigated in the present work. The jet trajectory, 2D/3D streamlines, flowfield evolutions, and frequency detections are discussed for two different velocity ratios (VR=2 and 4). Featured flow structures are identified and found to be closely related to the crossflow entrainment. The scalar mixing efficiency is carefully evaluated and further quantified through the statistical analysis. Both the flow dynamics and mixing process are analyzed using the proper orthogonal decomposition (POD) technique and dominant phenomena are extracted.