Ahead of today's sole free practice session, the air temperature is 21 degrees C, and the track temperature is 23 degrees. Although overcast, it is dry. However, there is a general consensus that there will be rain within the next hour.

The lights go green, and, as ever, Giancarlo Fisichella leads the way. Alonso, Kovalainen and Hamilton are also eager to get to work.

Five minutes into the session, fifteen drivers have been out for an installation lap, only Trulli, the Hondas and Ferraris have not been out. That said, moments later, Barrichello, who like his teammate looks likely to be retained next season, heads down the pitlane.

As Barrichello begins a second lap, Trulli, Button and Glock leave their garages. It isn't long before we have the first times of the day, Button posting 1:18.645, as Trulli and Glock go second and third.

With ten minutes of the session gone, Rosberg is advised that there will be rain in approximately half-an-hour, and that it is best to get to work.

A 17.242 sees Bourdais go quickest, as Bernie Ecclestone stalks the pitlane, inspecting his empire. Elsewhere, Barrichello and Bourdais both have minor off-track excursions.

As Vettel raises the benchmark with a 16.579, Massa heads down the pitlane. Hamilton and Kovalainen are on track also.

On his first flying lap, Hamilton confirms that yesterday's pace was no flash in the pan, he crosses the line at 16.484 to go quickest. However, moments later, Vettel posts 16.432.

As Raikkonen leaves the pits, Massa goes third and Kovalainen seventeenth. Elsewhere, Bourdais complains about the handling of his car.

Kovalainen goes quickest in the second sector, and again in the third, shooting up to the top of the timesheet with a 16.219. Raikkonen goes fifth with a 16.890.

Kovalainen consolidates his top spot with a 16.032, as Piquet goes sixth, ahead of Rosberg, Nakajima and Bourdais. Webber and Coulthard, the only drivers who haven't yet posted a time, are both on track. The Scot goes sixth with a 16.847, as his Australian teammate goes eighteenth 17.625.

Piquet improves to third with a 16.474, this being the track where his Dad had that memorable punch-up with Salazar back in 1982.

Despite going wide at the last corner, Massa goes second with a 16.092, as Webber improves to eleventh.

A strong final sector sees Hamilton close to within eight-thousandths of his McLaren teammate. Vettel also looks set to improve on fourth, but loses time behind a BMW.

Talking of BMW, despite having completed twelve lap each, Heidfeld and Kubica are running eighteenth and nineteenth. Normally it is Friday when they opt for consistency over pace.

Kovalainen raises the benchmark with a 15.858, and despite going quickest in the final two sectors of his next lap fails to improve.

Piquet locks up at the hairpin and heads off onto the wide concrete expanse. Raikkonen and Massa are back on track.

Webber moves up to seventh courtesy of a 16.558, the top ten now covered by 1.08s.

Massa goes quickest in the first sector, and again in the second, he's 0.267s up on Kovalainen. At the line it's 15.693, the Brazilian going quickest by 0.165s.

With fifteen minutes remaining, the BMWs and Trulli are at the wrong end of the timesheets. The Hondas also, but we weren't really expecting much more from them at this stage. Even Alonso is a lowly thirteenth.

Kubica, who went off in yesterday's opening session, looks to have more trouble on his hands, his car going very slowly. "If I apply the power the car pulls to one side," he tells his crew. On the pit-wall, Theissen looks worried.

Just Barrichello, Button and Trulli on track, with ten minutes remaining.

Hamilton is back on track, the Englishman one of the first to run the soft (medium) option tyre today. He posts a personal best in the first sector, and again in the second. At the line it's 15.839 as he moves up to second, 0.146s off Massa's pace. He's looking good to improve on his next lap but gets it all wrong at Turn 16, the entry to Sudkurve.

Five minutes to go, and with no sign of rain, indeed, the sun is shining, the final assault begins.