Ahead of today's opening free practice session, the air temperature is 17 degrees C, while the track temperature is 16 degrees. Following heavy overnight rain, which has left the track damp, the session is declared 'wet'.

The lights go green, and Adrian Sutil, one of five - yes five, twenty percent of the grid - local heroes, leads the way. Over the next three minutes, no less than fourteen drivers go out for their installation lap, including the McLaren duo.

Nine minutes into the session, Rubens Barrichello heads down the pitlane, leaving Raikkonen and Massa as the only drivers yet to make an appearance. In fact, Kimi is at the back of the Ferrari garage wearing his Ferrari anorak with the hood up. It rains for a couple of minutes and then stops.

Vettel, Piquet, Hamilton and Trulli are back on track, however, it's some time before the first times are posted.

After twenty minutes, just seven drivers have posted times, Alonso setting the pace with a 1:30.267. Shortly afterwards, it begins to rain again. Several drivers spin, including Hamilton.

A 29.774 sees Hamilton go quickest, as Kovalainen heads off on to the grass. Moments later, Alonso re-takes the top spot with a 28.572.

Twenty-nine minutes into the session, with the rain still falling, the Ferraris are on track.

Nakajima goes second, ahead of Hamilton, Sutil, Trulli and Kovalainen.

Massa goes fourth and Raikkonen eleventh, as Vettel goes quickest in sectors two and three to go second overall.

As the rain appears to cease, Raikkonen goes fourth, but is demoted moments later when his teammate goes quickest (28.004). Fisichella goes sixth, clear proof that like (fellow-oldie) Rubens Barrichello these conditions suit the more mature driver.

A 27.581 sees Raikkonen go quickest, while moments later he goes faster still, crossing the line at 26.473. Nick Heidfeld clearly has a problem, other than his installation lap the German has not been seen this morning.

Massa takes the top spot with a 25.888, the misery of Silverstone seemingly behind him.

Approaching half-time, there are just two drivers on track, Massa and Vettel. The Ferrari driver has raised the benchmark with a 24.828. There is a dry line emerging, but rain clouds still fill the sky. Vettel is the first driver this morning to use dry tyres (hard).

Vettel's switch to dries pays off, the German goes quickest with 24.087. This is the cue for his rivals to follow his lead and switch rubber. His next lap, 22.381, confirms that the time to change has arrived.

Nick Heidfeld waits patiently at the back of the BMW garage as his crew work on his car. The German is sporting a smart new livery on his helmet this weekend.

Thus far, it's a good session for force India, with Fisichella and Sutil third and fourth. However, it's highly unlikely that they'll be in those positions for much longer. Indeed, Bourdais goes second with a 24.817, bumping the Force Indias to fourth and fifth.

Finally, Heidfeld is on track, and it isn't long before the German is fourth, and looking likely to improve.

"It just let go," Sebastien Bourdais tells his crew, as he pulls his Toro Rosso off to the side of the track.

A 21.325 sees Adrian Sutil go quickest, ahead of Vettel, Bourdais and Heidfeld.

The home crowd must be loving this; Sutil is quickest, ahead of Heidfeld and Glock, with Vettel fifth. Moments later, Rosberg goes second (19.657), making it all five German drivers in the top six.

An 18.921 sees Rosberg take the top spot, just as Webber is told that rain is expected within the next ten minutes. Twenty-four minutes of the session remaining.

No sooner has Fisichella gone second than Timo Glock goes quickest, the Toyota driver crossing the line at 18.404. However, all eyes are now on Massa and Raikkonen, who are both on track.

Rosberg re-takes the top spot (18.018), as Piquet goes second, ahead of Glock and Sutil. However, Webber goes quickest in the first sector. Sure enough, the Webber driver goes quickest, crossing the line at 17.919. Moments later though, the Australian is demoted by Raikkonen and then Massa as the Ferraris make it a 1-2.