Hard to think it was over heating when your temp gauge indicated it wasn't.
In 50 degree weather, your radiator can leak a bit of coolant onto the external surface of the radiator and it will cause significant steam....maybe giving the impression that it was overheating. I pulled into the car wash the other day, having only drive two miles. I sprayed water onto the radiator and steam came off of it.....air temp was in the mid 50s.
You have a '97.....and unless your radiator was already replaced, you are past due for a radiator. TJ radiators use a metal core and a plastic tank up top. It is NOT at all uncommon for the seams to start leaking. It has happened to thousands of TJ owners over the years (myself included).
My bet....your radiator is leaking and causing steam on the external surface of your radiator.