Kentucky Derby 2018 Weather: Latest Forecast After Rain Rocks Churchill Downs

All eyes in the horse racing world are on the radar to see whether the rain will move away from Churchill Downs before the 2018 Kentucky Derby, which is scheduled for a 6:46 p.m. ET post time Saturday in Louisville, Kentucky.

Chris Bailey of WKYT provided an updated look at the weather map:

WBIR Weather noted it's possible rain showers will linger during the race:

WDRB chief meteorologist Marc Weinberg reported there is a flash flood warning for Churchill Downs:

The Weather Channel projects a 40 percent chance of rain at 6 p.m. and drops it to 15 percent at 7 p.m.

Although the outlook for race time remains unsettled, the weather has already had an impact at the betting window.

My Boy Jack, who opened as a 30-1 long shot in the morning-line odds, is now listed as the race's second choice at 5-1 behind favorite Justify (3-1), according to the Kentucky Derby's official website.

The surge in support is likely because of his victory in February's Southwest Stakes at Oaklawn Park in Arkansas, which was contested in the slop. That, paired with his victory last time out in the Stonestreet Lexington Stakes, make him an unexpected top choice in the Derby.

Justify also owns experience in the mud, winning an Allowance Optional Claiming race in March at Santa Anita Park in wet conditions.

All told, even if the rain stops before the horses arrive in the post, it's unlikely the track will have enough time to dry ahead of the race's 144th running. So weather will play a role in determining the winner of the year's first Triple Crown race.