A magnetohydrodynamic (MHD) numerical simulation model is used to study the magnetospheric state during the Geospace Environment Modeling (GEM) challenge period on January 27--28, 1992. Direct comparisons are made between the simulation results and the GEM Program data as summarized in the synoptic maps. The features we concentrate on are the cross-polar convection measurements and the ionospheric projection of magnetospheric boundaries. The results show good agreement at times and locations and poor agreement at other times. All in all, the results are rather mixed. We discuss the results and what they might mean for the accuracy of both the simulations and the synoptic maps. Moreover, we relate the results to other previous research on the cross-polar potential and draw guidance for future work. ¿ 1998 American Geophysical Union