Probably there are some similar or related ideas. While watching the NASCAR Truck Series today I was thiking about a way to deal with: Realistic Weather + NASCAR + Online/League Racing. Let me explain my idea with an example. Some league set the realistic weather for an online Nascar race, but the last half of the race it's likely to rain. The race starts and goes on with dry weather and then starts raining. As Nascar doesn't race on wet road, the race manager could throw a red flag (the same way he can throw YFs), pausing the race and forcing all drivers to go back to the pits, and then the game go back to lobby screen. As soon as all the cars are off the track, the game activates time acceleration. So the race manager can wait until the rain stops and the track to dry, or if it gets too dark (or other reason) he can just save the driver's line up and restart weekend, pretending as the race was postponed to the next day. I don't know how the rule codes works on rF2, but it doesn't seems too hard to achieve to me, just needs linking some already built-in features.
I don't really get why you'd want a red flag in that situation when all you'll end up doing is running the rest of the race in dry conditions at a later point. I do understand that you want to replicate reality so I guess that is your point. But it just sounds like a lot of wasted time in between where you're not racing and all you'll end up doing is effectively restart a weekend from scratch. For a series that doesn't run in the wet, I'd have thought you'd set the conditions so that it wouldn't rain rather than setting it random and hoping it doesn't. What if it starts raining on lap 2? Or the penultimate lap?
Is part of NASCAR racing strategy to deal with an possible rain shower. In a race of 500 laps a lot of drivers wait to final 50 or 100 laps to go agressive towards lead. But, if there's some possibility to rain the race could finish after 250 laps complete. It changes everything.
