Steven P. McNicoll wrote:

The FAA spokesman said at least one of the Southwest flights missed an
approach. Did they begin an approach when the observed weather was below
minimums?

Probably not, I doubt they'd pull anything that blatant so short a time
after the Midway incident. Maybe the fog was just rolling in; there
must be more to that story.

I can only find one of the flights on FlightAware, SWA946 departed BWI
at 11:57pm EDT and landed back at BWI at 12:38am. It seems to have
turned around a bit past halfway between Trenton and Manhattan.

SWA1729 arrived at PVD (and I suppose landed) at 11:51pm and COA163
arrived at 1:36am that night.