Measurements made with the Sondrestrom incoherent scatter radar during the April 17, 2002 magnetic storm are presented. The magnetic storm produced strong convection electric fields with no particle precipitation at Sondrestrom. The observed increase in the E-region electron temperature was caused by the anomalous electron heating in the altitude range of 100--120 km, where Farley-Buneman turbulence is localized. An model of anomalous electron heating was validated by comparison with the ISR data. Estimates of electron density perturbations during the strong electric fields show a good agreement with the model that accounts for suppression of the electron/ion recombination rate due to anomalous electron heating. The observed increase in the electron density leads to modification of the ionospheric conductivity. This effect is of importance for ionosphere--magnetosphere coupling, and should be included in global models that are developed for space weather forecast.