Laser-doppler anemometry and computational fluid dynamics methods have been combined to characterize the strong interaction nearfield evolution of the steady, subsonic, turbulent three-dimensional external aerodynamic flowfield for a high speed jet issued perpendicular to an imposed crossflow. A parabolic Navier-Stokes CFD solver is employed, utilizing a κ-ϵ closure system with algebraic Reynolds stress equation, in concert with porous farfield boundary conditions and a virtual source initialization procedure. The CFD results correlate well with the nearfield LDA data for three-dimensional distributions of mean velocity, and the rms fluctuation velocity components interpolated to turbulent kinetic energy. The CFD results downfield from the strong interaction region predict the vortex roll-up and jet cross-section/deflection/entertainment characterization verified by available mean velocity data. Results are presented for a circular VSTOL jet for jet/crossflow velocity ratios ranging 4 to 8.