Posted March 31st, 2018, 12:39 AM
One more thought, I did allow two hours to make it through ... in the middle of the day they might have all of the immigration booths working ... Houston's immigration this week at 7 pm and they had ONE agent working for all of the US citizens ...Well, how long did it take you to get out of HOU airport.
From your post above, AA & other airlines at JFK's T-8 are busy with int'l arrivals & departures all day, evening & into the night; and, as the largest terminal with 2 "banks" of gates - they will have more than 1 or 2 CBP agents working, airport ops quoting the capacity to process 1,600 pax per hour ... sounds good, but that's about 5 or 6 jumbo wide-body jets landing hourly and not that difficult to overwhelm the systems.
Anyway, the connection is supposed to be fine with a 4 hour window and you have about 5 hours in total ... assuming the flight is on time and not significantly delayed. You SHOULD be able to deplane, get thru APC area under CBP, wait & retrieve your luggage (unless doing just carry-on) and then, proceed past custom inspection area out to ground transportation ... in 2 hours, I would add extra 30 minutes for walking, taxi lines & luggage & gate delays, and possible FAA ground stops, etc. Your flight looked to be a 777 and if you are in the back section of the bird, deplaning could take + 10 or 15 minutes, while those in F & J/B get to walk off ahead of those in coach.
The drive from JFK to LGA - Southwest is Central Terminal or T-B - should be 45 to 60 minutes for the afternoon rush hour ... (unless there is an afternoon NY Mets baseball game nearby, causing more delays) putting you, hopefully, curbside at LGA no later than 4:30 PM, run inside - get your luggage dropped off, go thru TSA & then a short walk to the gate.
Unless weather is a factor or there's a major traffic incident on the highways between the airports - for simplicity, I would stick with yellow taxi (fares/tips, should run $45 to $55 at most) and they will be outside with a dispatcher working the taxi line, keeping things moving along nicely.
AirTrain to Jamaica Station, transfer to the E subway line, and then the SBS Q70 bus from Woodside/Jackson Heights in Queens to LGA is best for someone familiar NY's mass transit & done it before, and comfortable doing all that with luggage in tow, using escalators & elevators - last thing to worry about "how to" in getting a receipt before boarding the SBS bus ... as that last mile before LGA is where the traffic/airport congestion is most unpredictable (lately, it seemed fine) - folks have been known to get out of their taxis, car services & walk/run to the terminals to avoid possibly missing their flights.
Google Maps/Navigation & Waze on a smart/iPhone will give you a good estimate of your connecting options and best ETA as you land - and plot alternative plans if warranted - check that before you deplane & enter the CBP area, or, you will have to wait until you get beyond the secured area to get an update.
Good luck & feel free to ask and do come back & share your success story, hopefully, a smooth trip getting home.