Wowza! This puzzle was tough for me. I had to reverse-engineer all kinds of stuff, and I never would have solved it without figuring out the theme first.

I pulled out 34D Ingredient in some medicinal teas: SENNA because I would have preferred a clue about the late Brazilian race car driver. If you haven’t watched the documentary on Netflix, please do so before it goes away on December 31. Even if you don’t inherently like motorsport, this is a compelling story, as my mom can attest. If you have surround sound, watch it in that environment. This is the first film I watched to take advantage of my Vizio 5.1.2 system with Dolby Atmos back when I could have Ari over to watch it with me because I had to share. Here I am being nostalgic about how good we had it a year ago. There are scenes from Ayrton Senna’s camera cockpit, and you hear the engine noise behind you and cars to the left and right. Newer shows like Formula 1 Drive to Survive also benefit greatly from surround sound, but watch Senna first because it’s going away.

The solution of this puzzle is one that yielded a grid that wasn’t exactly what I’d filled out. I had put in the first letter of each word that was contained in the circles.

20A 10th and 11th, e.g.: EXT(R)NINGS -> EXT(RAIN)NINGS. You know, free baseball.
4D High rollers?: ELT(R)S -> ELT(RAIN)S. I had had this as ELITES and then ELT_K because I mistakenly had thought that 23A Westernmost country in continental Afr.: SEN[EGAL] was KEN[YA].
18A Interval for a scheduled blastoff: LAUNCH(W)OW -> LAUNCH(WIND)OW. I had attempted to attend a launch of the Orbiting Carbon Observatory 2 (OCO-2) at Vandenberg AFB on July 1, 2014. It had a 30-second launch window, and as the slated time drew near, we heard, “HOLD HOLD HOLD,” and half a minute later, everyone dejectedly started walking back to the buses. I then went home because there was a real chance it would not go up the next night. It did, so I missed it. It would have been a real launch wow, though.
11D Puts back in its original state, as a videotape: RE(W)S -> RE(WIND)S. I think REWS works, too, but it didn’t indicate an abbreviation, so it doesn’t.
57A Rend: TEARA(S)DER -> TEARA(SUN)DER. TEARSDER doesn’t mean anything.
53D Scary cry on a beach: T(S)NAMI -> T(SUN)AMI. Prior to figuring out what the circles meant, I figured it was SHARK! Then I knew that the circles contained some word, so I thought it might be ITSASHARK!
63A Wonder-ful product?: SL(I)DBREAD -> SL(ICE)DBREAD. I had expected this to be WHITEBREAD early on.
56D Enemy of Antony, in ancient Rome: CIRO -> C(ICE)RO. I didn’t know if 66A ___ Honor: was HIS or HER. I had _(I)_O, and I went through the letters and realized quickly that it was CICE_O, so CICERO and there fore HER.

40A Carriers of meteorological instruments … as suggested by this puzzle’s theme?: WEATHERBALLOONS because WIND, RAIN, SUN, ICE. Early on I figured that the circles, in order, were W, I, N, D. That was proved incorrect.

Finished this Wednesday puzzle in 30:51.