B737-700
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 115; Flight Crew Type 5700
Confusion; Situational Awareness
Inflight Event / Encounter Unstabilized Approach; Inflight Event / Encounter Weather / Turbulence
Flight Crew Executed Go Around / Missed Approach
Human Factors; Weather
We passed through 1;000 ft. AGL with a stable approach. Not long below 1;000 ft. AGL; the Captain turned off the autopilot and autothrottles. Soon we began to experience what I thought to just be turbulence from the heat of the morning. Along with the turbulence; the Captain began to say he felt something unusual happening with how the aircraft was flying. He said he felt an unusual rolling tendency. He increased speed slightly to gain more control. I rechecked the configuration of the flaps and gear. I was beginning to feel uncomfortable and also noticed we were becoming high. I suggested a go-around. The Captain immediately called for and executed a go-around. After level off; I confirmed the aircraft configuration again and reviewed the ZFW/landing weight. Then I requested new landing data for flaps 30 and 40. All the data looked correct for a 115;000 pound aircraft. The Captain asked for flaps 40 speeds and selected MAX autobrakes. We extended the downwind some to set up for the approach and make sure we were on the same page. If the Captain felt the same again; we'd go around and probably divert to a longer runway. We were both a bit flustered; so I tried to be very intentional at this point.The second approach was stable at 1;000 ft. AGL; but we noticed a 7-kt. tailwind. Wind was reported calm on the ground. The aircraft flew normally. As we went through 200 ft. AGL; we were slightly high on the glideslope; but the VASI showed on glidepath. Nearing touchdown; I felt the aircraft begin to float. I believe we landed long; but I don't know for sure. After touchdown; with MAX braking from the autobrakes; the Captain forgot to deploy the thrust reversers and I missed the 'Deployed' call out. We cleared the runway on the high speed taxiway.After the go-around; we should have spent more time talking about what had just happened and to calm ourselves. Maybe even get someone on the ground in the loop. Since I wasn't flying; I didn't understand what the Captain felt in the aircraft. We could have been better prepared mentally for the second approach had we communicated a little more before starting it. At that point; I suspect it may have been some unusual turbulence that was felt during the first approach. The use of MAX brakes on the landing was violent and with the previously experienced approach; it was too easy to miss the reversers. Spending more time talking things through may have helped be more focused during landing.
B737 First Officer reported the Captain executed a go-around after experiencing an unusual rolling tendency on final approach.