Ahead of today's free practice session the air temperature is 19 degrees C, while the track temperature is 21 degrees. Like yesterday, it is raining. Not heavy, but that fine rain which is often worse.

It's thought that that it will clear up before the end of the session, but then it is 80% likely to return for qualifying.

Nico Rosberg topped the timesheets in both of yesterday's sessions, the German edging out the Red Bull duo in the final moments of FP2 after they appeared to have it sewn up.

While a number of drivers are happy with the conditions, this being their one chance to level the playing field, others, especially Lewis Hamilton, are far from happy, the Mercedes driver claiming his car is bad enough in the dry.

The tyre compounds this weekend are hard and medium, though we have yet to see them. Yesterday it was all wets and Inters, though Sebastian Vettel completed one (yes, one) lap on the 2014 prototype tyres that Pirelli had brought along.

There are two DRS zones, one on the main pit straight and the other on the back straight between Turns 3 and 4.

In the minutes before the session Alonso poses for a team photo with his crew, the Spaniard and his boys opting for the dry garage as opposed to McLaren earlier which had its team picture taken in the open.

The lights go green and Gutierrez leads Bianchi, both on the full wets. It is raining a lot harder as Maldonado, Bottas, Chilton and Van der Garde follow.

While most return to the comfort, and safety, of their garages, Gutierrez stays out to post the first time of the day (34.837).

Vettel is among the early risers, but he too opts for the one lap. "Quite a lot of aquaplaning, looks tricky out there," says his engineer Rocky. Meanwhile, Gutierrez improves with a 34.671.

Gutierrez continues to slither his way around the track, the Mexican now down to 34.129.

As the rain increases in intensity, Rosberg is warned of "standing water on the right hand side of the front (pit) straight".

Several teams, including Mercedes and Red Bull, claim it is wetter than yesterday.

"I'll box this lap, there's some tyre shuddering, as in imbalance," says Button" "OK, we'll take a look at it," comes the response.

Approaching twenty minutes into the session, all but the Toro Rosso duo have made an appearance while Gutierrez remains the only driver to have posted a time.

As Hamilton ventures down the pitlane, the team tweets that the rain is coming down even heavier. "Water level is higher than the last run, so just exercise caution," the English driver is told.

"Take it easy on the straights, no cars have been running, so lots of standing water," he is warned, "lots of standing water up the hill". He subsequently dives into the pits.

"We got you in the car because the weather's so unpredictable," Pic is told, "there might be a break for some running." The Frenchman is also advised to mind the pit entry white blend line.

Bianchi, Chilton and Hulkenberg head down the pitlane, all on the full wets.

"Will this get better, because it's super oversteery, need to come back on aero balance" says Hulkenberg. "Feels a hell of a lot on the nose," he adds, having been told to pit.

Chilton crosses the line to post the second time of the day (36.654) with teammate Bianchi posting 34.129 moments later.

The rain has now stopped but Pic is advised that it is about to resume. The Caterham driver is also told to take care of the full wets on his run "because they're part of our allocation".

Bianchi posts 33.412, to go quickest, but this is almost instantly beaten by Bottas who stops the clock at 33.772, the Finn having a hellish wobble in T2.

Vettel runs wide in T4, but subsequently posts 31.857 to go quickest.