Neutral wind observations over the 100- to 200-km height region at Arecibo are presented for a summer, an equinox, and a winter period. Observations confirm that the wind below 110 km is predominately diurnal, with a vertical wavelength of about 20 km, and can be identified with the S1.1 mode. This tide reaches amplitudes of 100 m/s near 100 km but exhibits large day to day and seasonal variation. The vertical energy flux associated with the S1.1 mode is of the order of 0.25 erg/cm2/s at 100 km. A semidiurnal oscillation dominates the wind field from about 115 km to at least 170 km during the summer and equinox observations. A nighttime intermediate layer of enhanced electron density consistently descends through the F1 valley in the postsunset hours along the convergent null in Vz associated with the semidiurnal winds. The S2.2 mode dominates the semidiurnal oscillation above 125 km during these periods, reaching a maximum amplitude of 90 m/s at 153 km. Higher-order modes contribute to the semidiurnal oscillation principally below 125 km during spring and summer but appear to dominate at all heights in the winter observations, when the S2.2 mode appears to be largely absent. The vertical energy flux associated with the S2.2 mode is at least an order of magnitude less than that associated with the S1.1 mode.