Comparison of the field-aligned and transverse temporal evolution obtained from the two different models of the unsheared arcade (Sect. 4.1), in response to the non-uniform coronal heating pulse. Upper (lower) four panels: time ordered snapshots of the temperature, density, pressure and field-aligned velocity as functions of position along (across) the magnetic field at y = 1.2 Mm (x = 25 Mm). The various solid curves represent the HD TRAC solution at different times (with the lines colour coded in a way that reflects the temporal evolution) and the dashed blue curves correspond to the MHD TRAC solution at these times.