It took just an 18-minute rain delay to make Stephen Tarpley's no-hitter official Tuesday night, but the left-hander said he already had a feeling it was a done deal.

"I could see the clouds in the distance and they were pretty menacing, I knew it was going to rain eventually," the Pirates southpaw said. "When I came out after the sixth, it wasn't raining, but I expected to go a little further. And then my coach came out and shook my hand and said I was getting close to the pitch count. When my manager shook my hand, I said, 'Dang, it's over.'"

The Pirates' No. 23 prospect ended up with a rain-shortened no-hitter when Class A West Virginia's game with Delmarva was called after six innings at Appalachian Power Park. The Power won, 3-0.

"It was great, I was really excited," said Tarpley. "I wasn't thinking about it during the game, but it was awesome. I didn't know I was up there on pitch count, I was just trying to go as far as possible."

He struck out four and walked one over six frames to throw the second West Virginia no-hitter this season -- Pittsburgh's South Atlantic League affiliate also tossed a no-no on April 15 when Jake Burnette, Jose Regalado and Eric Dorsch combined on over seven innings in a 1-0 loss to Hagerstown.

Tarpley (5-2) retired the first four batters he faced before Yermin Mercedes reached on a throwing error by third baseman Jordan Luplow in the second. The left-hander worked a 1-2-3 third before pitching around shortstop Cole Tucker's throwing error and a one-out walk to Cameron Kneeland in the fourth -- Mercedes popped out and got Derek Peterson to ground into a fielder's choice to end the frame.

Delmarva went down in order in the fifth and sixth. Elvis Escobar hit an RBI double for the Power in the bottom of the frame for a 3-0 lead before stormy weather halted play.

The father-son umpiring crew of Ronnie Whiting Jr. and Ronnie Whiting Sr. then waited 18 minutes before calling the game. Tarpley was in the locker room when he found out, prompting teammates to offer handshakes and hugs.

"We were in the clubhouse, it started raining heavy, we got the tarp on, and about 20 minutes later, the umpires called it," Tarpley said. "When [manager Brian] Esposito shook my hand, I looked up at the scoreboard and knew. I was like, 'Oh, nice!'"

Power catcher Taylor Gushue was one of many to quickly congratulate the starter.

"He was like, 'That was huge, that was awesome.' It was cool, everyone shook my hand, gave me a hug," Tarpley said. "We were all cheering, it was cool to get that support from the team, to know they have my back in that situation."

Tarpley joined the Bucs on Jan. 27 when the Orioles traded him and a player to be named later for outfielder Travis Snider. He was ranked as Baltimore's No. 14 prospect at the time of the deal.

The roster for Delmarva, an Orioles affiliate, is full of Tarpley's former teammates, something that gave the 22-year-old a little bit of an edge Tuesday.

"I had faced these guys a lot in Spring Training in the past and instructs, and during the season, I got to see them play a whole bunch, so I knew a lot of these guys. A lot of them are my buddies," Tarpley said. "That was a mini scouting report within itself.

"I knew the hits weren't really there the whole time," he added. "I was keeping them where I wanted them. And then I got my handshake and thought, ''Wow, I did throw a no-hitter,' so that was pretty cool. But I wasn't thinking about it during the game."

Tarpley kept the Shorebirds off balance all night by starting batters with off-speed offerings and inducing 10 ground balls.

"I was using all my pitches, using both sides of the plate," he said. "With runners on, I knew they would be swinging early. Fastball in the zone, I would try to get ahead with my changeup and move them low-in. That opened the outer half for me. I was able to throw outside, hold runners -- I was using all my pitches pretty effectively today and I was glad they were all working. I tried to get ahead and get weak contact."

The southpaw overcame some sore arm issues early in Spring Training this year before finally making his Pirates organizational debut on May 25 with West Virginia.

"One day I missed a start due to it, but then I started a throwing program back up, I was able to come back and do what I wanted to do and got better," Tarpley said. "I thought of it as a positive thing."

Tuesday's no-hitter has been the highlight of what's turned out to be a nice season so far for the Los Angeles native. An Orioles' third-round pick in 2013, Tarpley said he's happy to be with the Pirates and the Power.

"It's been awesome, no complaints," he said. "I pitched on the road, there were some long bus rides I had to deal with, but it was great, I'm happy to be out here. These guys have been great behind me, my teammates have all been great."

Tarpley's no-hitter was the 10th in the Minors this season.