Apparently some species in the Camponotus sansabeanus complex (which includes semitestaceus) will fly August through October. You'll probably find them late at night after 8 PM or so, and after a hot day following some rain.
I went to my spot around 8pm and found two different colonies of this species. I'm sure there are a bunch more out at there I just need to look around a bit more. My weather app says there is a 50% chance for rain on Monday do you think they will fly after the rain? Also what would be the best method of catching the queens? Walking around staring at the ground with collection containers ready?
I'd bring a flashlight with you and stay a little bit later. Apparently some are flying now, from what I've heard. If it does rain Monday, they'll fly within the next few days. Higher chance on warmer days, but I'd still check even if it doesn't get that hot. You'll never know what you find.