Analysis of the 17 April 1995 data collected by the National Center for Atmospheric Research airborne Electra Doppler Radar (ELDORA) during the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX) was used to investigate the wind structure hypothesized in conceptual models of hail growth in supercell storms proposed by Browning and Foote in 1976. For the first time Doppler radar data resolved a horizontal vortex tube that resembles Browning and Foote's model. This supercell produced 1.75 inch diameter hail and an F1 tornado. In conjunction with 3-D variational analysis, ELDORA's data resolved fine scale convective structures and internal circulations within the supercell storm. The wind field and vertical vorticity calculation confirmed the existence of a mesocyclone-strength cyclonic rotation that coincided with the reported tornado. The horizontal vorticity and wind field also confirmed the existence of an anticyclonic horizontal vortex tube with a vorticity comparable to the mesocyclone. Particle trajectory analyses confirm that the horizontal vortex tube does support hail formation, but strong updraft regions also support hail formation. A delicate balance between hailstone embryo size, location, trajectory, and storm structure was realized.