This is the weekend all true racing enthusiasts live and die for. With the Indianapolis 500, the Monaco Grand Prix and the NASCAR Coke 600 at Charlotte, tomorrow delivers the season’s greatest sampling of marquee events in a single day. Questions abound, all to be resolved on Sunday. Here’s where you go to catch every minute of the action, all of it live.

We’ll start with Indianapolis, appropriate given this Joe Skibinski photo from IMS. The 103rd running of the world’s greatest race is facing the threat of rain, as it has all week. The latest from the National Weather Service shows a chance of showers and thunderstorms early tomorrow, and that more thunderstorms, some potentially severe, are possible after 3 p.m. The overall probability of precipitation during the day is 60 percent, meaning the 500 could end up being a sprint race to reach the halfway-plus-one-lap distance that makes the race official, rather than face a sodden postponement to Monday. With one 500 win under his belt, the Brazilian Tony Kanaan posted the fastest lap during Carb Day practice yesterday, driving for the immortal A.J. Foyt. Can one of the Indy-only teams somehow pull out a win over the multi-car juggernauts? Might Helio Castroneves finally achieve his fourth victory for Team Penske? Live race coverage, on NBC for the first time, begins at 12 noon.
Monaco is arguably the world’s most spectacularly picturesque racing circuit, the street course through Monte Carlo tracing its roots to well before World War II. The narrowness of the place makes passing increasingly difficult for modern Formula 1 cars, but hey, this is Monaco. To absolutely no one’s surprise, Lewis Hamilton is on pole, portending the chance of yet another 1-2 Mercedes sweep in this season of unfettered dominance. Will an also-ran somehow manage to slip by? Live coverage begins at 8:30 a.m. EDT on ESPN; the grand prix will be rerun beginning at 3:30 p.m. on ABC, the erstwhile home of the Indy 500. As to Charlotte, it’s a night race that’s expected to run under largely favorable skies, albeit with temperatures in the 90s. One unanswered question is whether Jimmie Johnson, who all but owned this place, can recover his winning ways sans longtime crew chief Chad Knaus, who’s now paired with Coke 600 pole-winner William Byron for Hendrick Motorsports. The live race telecast on FOX begins at 6 p.m. Sit back,, watch and take in a historic day.