We present Far Ultraviolet Spectroscopic Explorer (FUSE) and Space Telescope
Imaging Spectrograph (STIS E140M) observations of the post-asymptotic giant
branch star ZNG 1 in the globular cluster Messier 5 (l=3.9, b=+47.7; d=7.5 kpc,
z=+5.3 kpc). High velocity absorption is seen in C IV, Si IV, O VI, and lower
ionization species at LSR velocities of -140 and -110 km/s. We conclude that
this gas is not circumstellar on the basis of photoionization models and path
length arguments. Thus, the high velocity gas along the ZNG 1 sight line is the
first evidence that highly-ionized HVCs can be found near the Galactic disk. We
measure the metallicity of these HVCs to be [O/H]=+0.22\pm0.10, the highest of
any known HVC. Given the clouds' metallicity and distance constraints, we
conclude that these HVCs have a Galactic origin. This sight line probes gas
toward the inner Galaxy, and we discuss the possibility that these HVCs may be
related to a Galactic nuclear wind or Galactic fountain circulation in the
inner regions of the Milky Way.Comment: 23 pages, 11 figures, 7 table