Torrential downpours and lingering humidity are a staple at the Citi Open, where late summer thunderstorms threaten play year after year. Among the players this year are Andy Murray, who withdrew from the tournament Friday, and Sloane Stephens, the defending U.S. Open champion who lost to Germany’s Andrea Petkovic on Wednesday. (Photos by Katherine Frey/The Washington Post) #tennis #citiopen #andymurray #sloane #sloanestephens #washington #dc #citiopen2018