Observed ionospheric F-region upflows associated with convection-driven frictional ion heating and soft electron precipitation at high latitudes are modeled with a dynamic ionospheric fluid code. Precipitating soft (≤1 keV) auroral electrons are effective in rapidly enhancing the F-region ionization and electron temperature, which leads to a strong upward plasma expansion. It is shown, for example, that an electron flux of 1 erg cm-2 s-1 with a characteristic energy of 150 eV can produce a 109 cm-2 s-1 O+ outflow at altitudes of 700--800 km. The more widely-recognized convection ion heating is indicated to be significant but somewhat smaller effects on the upflows. We have performed comparisons with published HILAT and DE-2 observations. Using a latitudinal distribution of ionospheric flux tubes with ''inputs'' of the observed average precipitating electron energies, energy fluxes and convection drift velocities, we find satisfactory agreement with latitudinal profiles of ion upflow velocities, densities, fluxes, and ion and electron temperatures. Therefore, we suggest that the combined effects of soft electron precipitation and frictional ion heating may be identified as the principal drivers of these upflows. ¿ American Geophysical Union 1995