  Modern gravitational-wave observatories require robust low-frequency active
seismic isolation in order to keep the interferometer at its ideal operating
conditions. Seismometers are used to measure both the motion of the ground and
isolated platform. These devices are susceptible to contamination from ground
tilt at frequencies below 0.1 Hz, particularly arising from wind-pressure
acting on building walls. Consequently, during LIGO's first observing run both
observatories suffered significant downtime when wind-speeds were above 7 m/s.
We describe the use of ground rotation sensors at the LIGO Hanford Observatory
to correct nearby ground seismometers to produce tilt-free ground translation
signals. The use of these signals for sensor correction control improved
low-frequency seismic isolation and allowed the observatory to operate under
wind speeds as high as $15-20$ m/s.
