Rain becomes a factor at Churchill Downs for Kentucky Derby

The 114th Kentucky Derby will go down as the wettest on record. It's been pouring in Louisville and the track has been downgraded from "fast" to "sloppy," since races began at 10:30 a.m. Saturday morning.

The National Weather Service in Louisville announced there is a flash flood warning for Louisville, and potentially, Churchill Downs.

A stream of fans headed for the exits nearly two hours before the race as a heavy downpour of rain pounded the area Saturday, the Associated Press reports. Many of the uncovered seats that sell for hundreds are empty as fans opted to cram under awnings and overhangs.

Otis Miller joined those who decided to leave. He and his friend were visiting from Cincinnati for their first Derby in the infield, where there is little shelter.

"I tried to bring the sun out on a rainy day with my yellow suit," he told the AP, "but Mother Nature won that battle."

Kentucky Derby odds changing like the weather

Some horses can run on wet or muddy track conditions. "Mudders," as they're called, are quite adept at the trickier track. 

Seven of the 20 horses racing in Saturday's Derby have competed in muddy or sloppy conditions. Odds on various horses who were originally considered long shots are now getting shorter. 

For example, My Boy Jack opened at 30-1 odds. But is now 5-1 to win, right behind Justify. Still the favorite to win, Justify is 2-0 racing in sloppy conditions, including a wet track win at the Santa Anita Derby earlier this year.. Justify, the favorite to win the first leg of the Triple Crown, is 2-0 on those tracks.