Ahead of today's opening free practice session the air temperature is 13 degrees C, while the track temperature is 18 degrees. It is windy, nippy and overcast with rain predicted at various stages over the weekend.

Tyre choices this weekend are medium (prime) and soft (option), while the DRS zones are on the start-finish straight and on the back straight leading to T14.

There's a new face in the paddock this morning, Marco Mattiacci, Ferrari's new Team Principal. However, with minutes to go before the start of the session we cannot see him indeed, we cannot see much in the Ferrari garage as the mechanics are lined up and blocking the view.

Felipe Nasr is standing in for Valtteri Bottas this morning whilst Giedo Van der Garde replaces Adrian Sutil at Sauber.

The lights go green and Magnussen is first out as mechanics are working furiously on Maldonado's car.

One by one the drivers take to the track for an installation lap, Ericsson reporting a few spots of rain.

Now on track, Maldonado spins on the approach to T9, the Lotus driver seemingly distracted by something in his cockpit. Replay shows just how bizarre the incident was, the Venezuelan turning right and then appearing to continue driving straight off the edge of the track as if asleep.

Sauber reveals that due to a clutch problem Gutierrez will miss the first forty minutes of the session.

As Pirelli says that the cool conditions mean that drivers need to generate heat into their tyres very quickly to avoid graining, Perez reveals that he is having such problems.

The threat of rain means that we don't have to wait as long as usual to get some times on the doors and soon Button leads the way (1:42.482) ahead of Magnussen, Massa, Rosberg, Perez and Kobayashi.

Rosberg improves with a 41.063, ahead of Alonso, Hamilton and Button.

Lots of lock-ups, including Frenchmen Vergne and Grosjean, both at T14, whilst Hulkenberg improves to fourth, ahead of Massa, Button, Ricciardo, Magnussen, Vettel and Perez.

Hamilton is told that he is two-tenth down on Rosberg in S1 and S2, and three-tenth is S3. The German is currently on 40.840 and his teammate 41.560, they are split by Alonso (41.304).

Raikkonen finally heads down the pitlane, one of the last drivers to appear, watched by his new boss.

After a brief period of inactivity, Grosjean is back on track, the Frenchman currently seventh (42.090).

At half-time, it's: Rosberg, Alonso, Hamilton, Hulkenberg, Massa, Button, Grosjean, Ricciardo, Magnussen and Vettel. No times as yet for Raikkonen, Gutierrez or Bianchi.

Kvyat spins at T1 after running wide and at first appears to be stuck in the gravel however, like an old pro he keeps the engine running and is able to continue.

More problems for Maldonado as the turning vane of his sidepod has comer loose and is now flapping.

Alonso improves by over a second to go quickest (39.783) as Raikkonen's misery continues, mechanics continuing to work on the Finn's car, which is understood to have a servo problem.