Ahead of today's sole practice session, the air temperature is 26 degrees C, and the track temperature is 34 degrees. The main thing however, is that unlike yesterday it is not only dry, it is bright and sunny. Woo-hoo! On the other hand there are a few dark clouds in the distance, officials predicting a 10% chance of rain.

Consequently, with both of yesterday's session run in the wet, and not a glimpse of the Pirelli slicks, we are in for a very busy sixty minutes. Indeed, the drivers have been given an extra set of option (medium) tyres for this session.

Talking of which, the dry tyre choices this weekend are hard and medium, and there is just one DRS zone and that's on the main pit straight.

With both yesterday's sessions washed out, Lewis Hamilton describing them as a waste of time, all the set up work has to be done this morning however, whilst it was previously forecast to be dry today and tomorrow there is now talk of showers on Sunday.

The big question, now that we're (weather-wise) effectively back to normal, is whether Singapore was a blip for Mercedes or whether Ferrari really is that little bit closer.

Ricciardo heads the queue at the end of the pitlane, and when the lights go green he doesn't wait for an invitation. In moments there are ten drivers on track including the Mercedes duo.

No installation laps today, having completed an out lap Ricciardo is straight down to business, indeed, only Raikkonen peels off into the pits.

Ricciardo posts the first time of the day (1:36.392), Sainz going second and Grosjean third. The Frenchman is on the options whilst everybody else is on primes.

A 36.926 sees Verstappen go second, until Bottas slips in a 36.926.

Massa complains that his "head rest is coming off".

Five minutes into the session and all but Button and the Ferraris have posted times.

Bottas' Williams goes airborne after clouting the kerbs at the chicane as Hamilton complains that "grip is very poor". That will be due to the rain yesterday and consequent lack of running.

"Still massive, massive understeer," says Button.

Ricciardo performs a race pitstop as he switches to the softer rubber. On the harder rubber the Australian's best time was 36.010, which is currently the benchmark.

"If you both keep talking I can't hear you," reveals Kvyat as his engineer and A. N. Other bark instructions into the radio.

On the option rubber Ricciardo goes quickest in the first two sectors, finally crossing the line at 34.755. Second placed Verstappen, on the harder rubber, is 1.454s behind.

With both Ferraris yet to post a time, Raikkonen is on track on the option rubber. His first lap on the options indeed, his first lap, sees the Finn go eleventh (39.363).

"I've got a big flat spot," complains Ericsson. Asked if he wants to continue it is decided that to do so would be a waste of time. He pits.

Mistakes aplenty as drivers explore every inch of the green - in almost every sense - track, drivers run wide, clout kerbs and are generally very untidy. A big moment, in particular, for Grosjean at Spoon.

As Raikkonen begins another flying lap, Vettel is also on track on the softer rubber.

Raikkonen can only improve to ninth (38.736), as Vettel, on his first alp, goes eighth (38.659).

The Toro Rosso duo, currently second and third, switch to the option rubber. The Dutchman posts 35.160 and his teammate 36.059 having been quickest in S3. Replay shows the Spaniard losing time after running wide in the second Degner.

After twenty-five minutes, Renault-powered cars fill the first four places.

Button (options) posts 36.174 to go fourth, as Sainz, again quickest in S3, posts 35.963 but stays third.

Button complains that the DRS warning 'beeps' are incorrect. He is not a happy bunny.

Ricciardo, still on options, goes quickest in S1, maintaining the pace in S2. As Bottas (option) goes second (35.128), Ricciardo crosses the line at 34.497. Elsewhere, teammate Kvyat runs wide at Spoon.

"Interesting mix of strategies between teams as some running low fuel and option tyres to start and some the opposite," tweets Mercedes.