The neutral response to the postmidnight diffuse aurora was calculated using observed fluxes of electron precipitation and a high-resolution, time-dependent numerical model. In an earlier work, based on an idealized representation of auroral precipitation, we simulated a dramatic supersonic E region jet stream. We suggested that hydrodynamical shear instabilities of this jet were responsible for eastward propagating features on the poleward edge of the diffuse aurora called omega bands. The results of the present study are qualitatively similar to the results of the previous study: A very strong dynamically unstable E region jet is simulated for an eletric field of 50 mV m-1, and the results suggest a connection with omega bands. The winds are not quite as strong as previously simulated; zonal winds speeds of ~600 m s-1 are achieved in -2 hours in the present study, whereas comparable wind speeds are achieved in ~1 hour in the earlier study. After 1 hour, the peak winds reached are ~400 m s-1 in the present study. The smaller acceleration for the present simulations is primarily a consequence of a smaller total energy flux in the observed fluxes than in the idealized ones. The zonal winds which we simulate are 2--3 times stronger than those previously simulated for the diffuse aurora elsewhere by a model of similar complexity. We have evaluated the effects of large-scale cross-arc winds, which were lacking in our earlier study, and found that strong cross-arc winds are required to prevent the formation of strong E region zonal jet. Our present results indicate that supersonic jets are possible. but are not apt to occur very often. ¿ American Geophysical Union 1989