Perhaps mindful of the rain radar showing worsening conditions rapidly approaching the 2.3-mile Barber Motorsports Park road course, Penske's Will Power was quick on his marks to get out and set what proved to be the fastest lap of the day early in first practice on Friday.
Power set his lap of 1:11.2886s (116.148mph) just his fast lap just after the 1pm, the halfway point of the hour-long practice 1 session that was divided into two half-hour groups with the earlier session reserved for rookies and drivers lower down the championship points.
"We have tested here a lot and know the track very well and the set-up very well," said Power. "We just made minor adjustments to the car because we basically know what we want.
Power's time was 0.2124s ahead of his team mate Helio Castroneves, and the Chevrolet 1-2 was mirrored by a Honda 3-4 which comprised Rahal Letterman Lanigan's Takuma Sato and Sarah Fisher Hartman Racing's impressive rookie Josef Newgarden.
"I think we had a good first session," said Newgarden. "We're certainly in the ballpark. We're not quite there, I think we need to make some adjustments and dial it in a bit more."
Rubens Barrichello looked comfortable to be on the sort of course that is much more familiar to him, and duly set the fifth fastest time of the session two hundredths ahead of Marco Andretti.
"What a difference it makes when you know the place," he agreed. "I have only done one test here, but it makes a huge difference compared to last weekend at St. Petersburg.
"Today was a day where I don't think anybody really had the chance to push the car to its limit," he continued. "It brings a new challenge to the weekend because we only have 20 minutes tomorrow before qualifying so we have a lot of work to do with the engineers tonight to make sure the car is good enough for qualifying."
The rain started to fall ten minutes from the end of the first session, but there were no significant incidents out on track despite the worsening conditions. However, back in pit lane the Dale Coyne Racing car of Justin Wilson suffered a fuel line fire in the engine compartment after just three laps of running. Wilson had to sit out the rest of the day while the team and Honda assessed the damage, to see if the fire was going to force them to change engines before Sunday's race.
If they do, then they will take a ten-place grid penalty for the race, as Oriol Servia will do after Dreyer & Reinbold were forced to swap out a Lotus engine in the late afternoon practice 2 session, with Servia pulling in to the pits on just his second lap. "The Lotus guys plugged in and said we'd need to change the motor," confirmed team co-owner Dennis Reinbold.
With the track wet from the start from a thunderstorm that passed over the area in the interval there was little chance of anyone doing any serious running. Sato set the fastest time of 1:18.8684s for the records, but only risked three laps out in the tricky conditions before calling it an early day given that the conditions are not expected to be representative of the rest of the Honda Indy Grand Prix of Alabama weekend.
"It was a dryer condition to begin with, which was relative," he said, although to put that in context he was still out on the wet Firestone tyres and was over seven seconds slower than Power's earlier fastest lap in practice 1.
The rain soon picked up again and the track became fully wet with rooster tails much in evidence even before the rain became a full downpour and forced the race officials to throw a red flag early to curtail the session. No one took any chances and there were no incidents; six drivers - Power, Castroneves, Ryan Briscoe, Simon Pagenaud, Mike Conway, Ed Carpenter - never even considered it worthwhile turning a wheel, along with the incapacitated Justin Wilson.
"By the weather forecast, it sounds like we're going to have a dry qualifying tomorrow and for Sunday it seems even better, so there is no point for us to go out there and take any chances at all," explained Castroneves. "We just wanted to do some stuff, but at the end of the day, the rain was getting a little bit too much."
"I think with the rain qualifying will be mixed up tomorrow and if the track has weepers there will be wet patches," added Power.
Full Friday practice session times