The Naval Research Laboratory (NRL) Sami3 is Also a Model of the Ionosphere (SAMI3) ionosphere/plasmasphere code is used to examine the physics of metallic layers at altitudes from 80 to 160 km. Results are presented near the simulated location of the Arecibo observatory (18N, 66W). We find that simulations, using winds from the empirical horizontal wind model (HWM14), produce layers consistent with those observed at Arecibo. Specifically, we find upper semidiurnal and lower diurnal traces similar to those identified in previous observational surveys. While metallic layers are shaped by meridional winds, zonal winds, and electric fields, much of the observed structure is found if only meridional wind forces are included in the model. Stratification below 110 km, where the ions are very weakly magnetized, is supported mainly by meridional wind shear.