BETHESDA, Md. -- With darkening skies and dangerous weather in the area, play was suspended at the AT&T National at 2:44 p.m. ET.
According to Vice President of Rules and Competition Mark Russell, the delay will be "at least an hour to an hour-and-a-half."
"Hopefully we can get back out and play," said Russell, who added that they need about 2 1/2 to 3 hours to finish the second round.
Roberto Castro and Jordan Spieth currently share the lead at 7 under aftre each shot 69 and 66, respectively, in the morning wave.
D.H. Lee is two back after a 66.
Andres Romero was making a move, playing his first 13 holes in 4 under, to get within two of the lead when the horn sounded.