Ahead of today's free practice session the air temperature is 18 degrees C, while the track temperature is 23 degrees. It is bright and sunny, even a little warmer… woo hoo!

It is altogether better than yesterday, but it is widely predicted that this afternoon's qualifying session will be hit by rain at one stage or another.

Jenson Button was quickest in yesterday morning's session, the Englishman posting his time early on before conditions began changing, while Pastor Maldonado topped the timesheets in the afternoon.

As previously reported, Red Bull broke the curfew for the first time yesterday, the Austrian outfit working on the gearbox on Mark Webber's car. It was eventually decided to change it resulting in a five-place grid penalty. Rosberg and Grosjean also have grid penalties following the British Grand Prix.

The changing conditions mean that we have yet to see the genuine pace of the cars here, or, indeed, the order of things. However, on the face of it Ferrari and Red Bull look strong.

McLaren has a raft of updates here however, the weather gods conspired to ensure we never got to see what benefit they were to the Woking team.

At Lotus, the Enstone outfit has opted to drop its controversial aero update, essentially a double DRS - for the remainder of the weekend.

The lights go green and Kobayashi leads the way, followed by Vergne, Glock, Perez, Ricciardo, Kovalainen and a whole host of others. Vergne is informed that there will be a "light shower in thirty minutes".

Already, some drivers are running on the soft tyres, most notably Glock, Ricciardo, Raikkonen, Hamilton and Button. Within moments all but Rosberg, di Resta and Pic are on track, the Marussia crew working furiously on the Frenchman's car.

While most return to the pits after an exploratory lap, many remain out, Raikkonen posts a 1:20.927, with Kobayashi going second ahead of Hulkenberg, Perez, Button, Grosjean, Ricciardo, Hamilton and Vergne.

Rosberg complains of something rubbing against his left elbow. Nonetheless, the German goes quickest with a 18.455.

Marussia reveals that Pic has an air leak in his engine, a complicated, long winded job.

Next time around, Rosberg ups the ante with a 17.971, the German on the medium rubber. Second quickest man, Raikkonen, is 2.836s slower.

Glock, on softs, goes second, closing to within 2.584s of Rosberg who immediately responds with a 17.491.

Thirteen minutes into the session Vettel comes out to play, the Red Bull shod with mediums. Elsewhere, Massa gets serious, the Brazilian banging in a 17.635.

A 17.391 sees Senna take the top spot, the Williams driver going quickest in the first and final sectors. Elsewhere, a big lock-up for Button at the hairpin.

Webber takes the top spot with a 17.331, the Australian, like Senna, on the softer rubber. Moments later the Australian is demoted by that man Maldonado… who crosses the line at 16.940.

The normal order of things is restored when Vettel, desperate to win in front of his home crowd, posts 16.876 to go quickest. However, moments later the German, who is on softs, is leapfrogged by Maldonado who is also on the softer compound. Determined not to be out-done, Vettel snatches it back with a 16.652.

Twenty-two minutes into the session, it's; Red Bull, Williams, Red Bull, Williams.

Approaching half-time, as the Marussia crew continues to work on Pic's car, only Perez is on track. The Mexican, currently sixth, is on mediums.

The current order is: Vettel, Maldonado, Webber, Senna, Alonso, Perez, Rosberg, Massa, Glock and Kovalainen.

Hulkenberg (soft) improves to sixth, having gone quickest in S2. Elsewhere, Perez posts 16.968 to go fourth.

Next time around Hulkenberg once again goes quickest in S2, however a poor final sector sees him fail to improve.