I live on approach to 15R at BOS. Early this morning I heard a craft flying very low and making an unusual noise. I opened a flight tracking app and saw Southwest WN1941 from STL miss its landing. It then flew down to Plymouth and turned. I thought it was going to make another approach to Logan from the south but instead it turned SW and climbed. It was diverted to BWI.
At around this time, other craft landed on 15R.
Seems unusual?
Given the weather my guess they got windshear on final and went around. After the go around they decided to go to their alternate of Baltimore, based on available fuel on board and possible holding for the weather to improve.
https://flightaware.com/live/flight/SWA1941/history/20191017/0210Z/KSTL/KBWI
I can’t see the weather at their arrival time but looking at the track log they had some fairly strong low level winds to drop their ground speed to as low as 89kts.