Ahead of today's all important qualifying session, the air temperature is 17 degrees C, while the track temperature is 25 degrees. The heavy rain shower at the end of FP3 went away as quickly as it had arrived and now, courtesy of the sun - a rare visitor to F1 circuits these days - we have an almost ideal track. We say almost because the rain will have washed away much of the rubber.

While this morning's session finally answered some of the questions, a number remain unanswered. Most importantly, while some drivers finally got to do a low fuel run on soft tyres, in anticipation of this afternoon, others didn't Indeed, tyre use this morning was strangely mixed, leaving us with no clear picture.

Certainly the Ferrari and Red Bull has the edge, however, the Williams is also looking very good here. Lotus, which really needs to up its performance in qualifying, remains a conundrum, while both Mercedes were uncharacteristically off the pace.

McLaren, which has a whole raft of updates here, is looking quite good though its still hard to tell, especially since Button failed to get in a low fuel run courtesy of the late appearance of the rain.

Grid position isn't as important here as at home track however, for Webber, Grosjean and Rosberg the situation isn't helped by the penalties they carry into today's session. Webber gets a five-place penalty after his team changed his gearbox overnight, while the other two carry over similar penalties from Silverstone.

In the minutes before the session gets underway, the wind picks up and a couple of teams, including Mercedes, warn that rain is on the way. Ferrari claims that it is thirty minutes away, in time for Q3.

The lights go green and the Force India head the queue at the end of the pitlane. With an eye on the big clouds in the distance, the Red Bull, Ferraris, indeed everyone is eager to get to work and get in the obligatory 'banker lap'.

Hulkenberg posts the first time of the afternoon, the German crossing the line at 1:18.475. Most are on medium rubber, though the four slower teams - which includes Toro Rosso - are on softs.

As Button goes quickest (16.737), Race Control claims there will be a five minute shower in thirty minutes.

As Grosjean runs wide, on-board with Hamilton reveals some ominous clouds in the distance.

A 16.705 sees Alonso go quickest, while Hamilton can only manage eight after a lock-up in the stadium.

Vettel's first flying lap is only good enough for fifteenth (17.849), as Hamilton takes the spot with a 16.383. A 16.507 from Button makes it a McLaren 1-2.

Other than the obvious problems, the rain will wash away the rubber that is being laid right now, the shower at the end of FP3 having washed away the previous layer of rubber and leaving the track 'green'.

Kobayashi splits the McLarens with a 16.481, the Sauber driver on medium, like the majority of his rivals. The quickest soft runner is Vergne who is currently fifteenth, 1.2s off the pace.

Replay shows Grosjean having a major wobble coming out of Turn 1, the Frenchman doing well to keep it all under control. A couple of similarly hairy wobbles this weekend, most notably Vergne's yesterday.

With 8:12 on the clock, Hulkenberg is in the danger zone, with the Toro Rossos and teammate di Resta hovering.

The Force India duo leave the pits, both shod with the softer rubber.

Raikkonen goes quickest in S1 as Hulkenberg goes second quickest overall, the Force India driver crossing the line at 16.271. Raikkonen posts 15.693 to go quickest.

As Webber slips down to thirteenth, and with rivals switching to the softs, the Australian will need to go out again, as might some of the drivers ahead of him.

Di Resta and Ricciardo are on hot laps as Vergne goes tenth (16.741).

As Alonso leaves the pits on softs and Schumacher on mediums, di Resta posts 16.352 to go fourth. Moments later, Ricciardo goes seventh (16.516).

Maldonado goes fourth but all eyes are on Rosberg who goes quickest in S1, the German, like his Mercedes teammate, on mediums. Grosjean, also on mediums, can only manage twelfth.