Originally Posted by
helicrazi
Shape, size, colour change at different ranges, showers tend to change colour as they get closer or you closer to them.
Wasn't it low cloud and fog that night? Would you be expecting a heavy shower in those conditions with a red return?
For an approach to land I would also have GMAP or GMAP 2 selected, so the return the radar is showing is most likely to be of the solid kind.
My point is that yes there are differences, but fairly minor ones as you describe. It is therefore not impossible that they disregarded the return as being weather (despite the actual weather being as you say) - or at least it is as valid an explanation as the radar being U/S. If the radar had actually been U/S, would they have continued with the approach?