For the fourth time in the 2009 Atlantic Championship, Jonathan Summerton will start from pole position after topping qualifying for the Grand Prix of Mosport after a weather-challenged qualifying session on Saturday afternoon.

The start of the session was slightly delayed due to wet and foggy conditions, and the scheduled 30-minute outing was eventually shortened by two minutes. While it rained significantly earlier in the day, however, the rain stopped prior to the start of qualifying and track conditions improved throughout.

The Newman Wachs team ensured that Summerton's #34 machine was well suited to the changing conditions, and the 21-year old American did the rest, turning a lap at 1min 12.060secs to take pole by more than three tenths of a second. Summerton previously took poles at Sebring in March, the first race of the double-header at New Jersey in June and earlier this month at Mid-Ohio, and heads into Sunday looking for his third victory of the season.

“It was fair for everybody,” he said following qualifying, “The track did dry up, probably about seven or eight laps from the end, and the whole track was very similar.

"Basically, we just kept pushing and I just had to keep the car on the edge. That's what everybody has been telling me it was. It was on the edge, but you've got to get it on pole and I think we had it by four tenths. The guys did a great job - Don Halliday, my engineer, all the team, and [team owner] Eddie Wachs. I'd like to thank them for allowing me to do this.”

Starting alongside Summerton on the front row will be points leader Simona de Silvestro in the #78 Team Stargate Worlds entry. The Swiss driver posted a lap of 1min 12.375secs to take second spot after setting the fifth-best time in Friday's practice. She has won four times this season and has finished on the podium in her last eight consecutive races.

“After the practices yesterday, I think we worked a little bit in the wrong direction,” de Silvestro said, “It kind of messed us up a little bit, but we were pretty confident that we had a car that could be quick.

"This morning, with the rain, it was good. Then, it started drying up, so you really had to push hard and not do a mistake - just try to put a lap in. Jonathan did a great job. He was a little bit quicker than us, as we tried to do something with the set-up for the rain, and I think we went a little bit overboard with it. But I'm really happy to start second, because [John] Edwards is our main competition for the championship and he's a little bit behind. We're going to try everything to win or at least finish on the podium.”

Rookie Frederic Vervisch starts from a familiar spot, as he put Genoa Racing's #17 car third on the grid for the fifth time in ten races this season. The Belgian has finished on the podium three times this season, with a best result of second in the season opener at Sebring, but is still looking for his first career Atlantic victory.