Incoherent scatter observations of E and F region drifts over Millstone Hill (42.6°N) were made routinely from May 1976 to November 1977 at monthly intervals. Some 667 hours of data gathered over this 19-month period were analyzed to yield the F region polarization electric field in the magnetic south and magnetic east directions. The data have been used to construct an analytical model for these two field components as functions of (1) local time, (2) day of year, and (3) magnetic activity (represented by the Kp index). Models were constructed both with and without the constraint that the daily average of the E-W field be zero. The model employs 35 coefficients for each electric field component which were found by a least mean squares fit to the data and are tabulated.