Wind measurements made with the chemical release technique during a sporadic E layer event are presented. The data were obtained as part of the Sporadic E Experiment over Kyushu (SEEK) sounding rocket campaign. The winds show a strong maximum in the lower E region approaching 150 m s-1 near 105-km altitude and a large shear below the maximum. The large shear was within a few kilometers altitude of the peak in the electron densities measured on the downleg of the rocket trajectory. Calculations of the Richardson numbers for the wind profile show that the altitude range near the layer was highly unstable. ¿ 1998 American Geophysical Union