Ahead of today's sole free practice session the air temperature is 27 degrees C while the track temperature is 38 degrees. Humidity is 82 percent. For much of the last week or so, storms have hit the track at around 16:00 and while conditions are ideal at present there is every chance that the weather will change later in the afternoon.
Mark Webber was quickest in both sessions yesterday though his Red Bull teammate and the McLaren duo were right up there - all four covered by 0.214s.
Their nearest rival was Michael Schumacher, who was almost a second adrift of Vettel, along with his teammate, the Ferraris - not where they expected to be - and Renaults. The next group consisted of the Williams, Force Indias, Saubers and Toro Rossos.
As expected, tyre wear was noticeable with marbles - and even Mat Coch's 'supermarbles' littering the track. Not only were we seeing tyre performance drop off rapidly, particularly the soft (option), thereby causing drivers to struggle for grip, any detour across the marbles usually ended in tears. The prime tyre, as in Australia, is the hard.
Renault's efforts were compromised by problems with the front uprights which were traced to a defective batch of components. At Virgin, a dramatic suspension failure at the end of the first session resulted in Jerome D'Ambrosio getting no running in the second despite the best efforts of his crew.
Overall, McLaren continues to show the good pace it had in Melbourne however, there is a widespread feeling that Red Bull, and particularly Vettel, has plenty in reserve. That includes KERS which the Austrian team does have this weekend but remains unsure whether it will be used. That said, it was used yesterday… we saw it on the onboard TV coverage.
Paul di Resta heads the queue at the end of the pitlane and when the lights go green he is followed on to the track by Perez, Alguersuari, Heidfeld, D'Ambrosio, Petrov, Buemi, Kobayashi and the Lotus duo.
Once the lead group have completed their installation laps, the Ferraris, Mercedes, McLarens and Red Bulls come out to play.
Twelve minutes into the session - which is unusually quiet compared to normal Saturday sessions - Petrov is the first out for a second run. The Russian is soon joined by Perez, Heidfeld, D'Ambrosio, Kobayashi and the Lotus duo.
Petrov posts a 1:47.673 and D'Ambrosio 47.957 while Trulli goes 5s quicker before his Lotus teammate posts 41.868.
It took a while to get started but now it's fast and furious, Petrov posts 39.884 only to be leapfrogged by Hamilton (39.563) and then Heidfeld (39.426). Hamilton's second lap - he's on a three lap run - sees the McLaren driver post 38.940.
Button makes it a McLaren 1-2 with a 39.172 as Petrov and Heidfeld make it a Renault 3-4.
Vettel's first flying lap sees the world champion go fifth with a 39.348, the German complaining that his (rear) wing isn't "stalling like I like it to stall".
Twenty-five minutes into the session, di Resta, Barrichello, Sutil and the Ferrari and Hispania duos are the only drivers yet to post a time.
Vettel returns to the pits now complaining that his wing isn't stalling at all. Elsewhere, Maldonado moves up to sixth, ahead of Perez, Rosberg, Buemi, Kobayashi, Alguersuari and Schumacher.
Alonso goes sixth (39.407) on his first flying lap however, the Spaniard is clearly struggling. Yesterday, Alonso admitted that his team has little chance of fighting for victory here.
Alonso improves to fourth and his teammate fifth but both are clearly struggling. Meanwhile, di Resta spins in the final corner as the DRS kicks in.
A 38.926 sees Massa go quickest, like his teammate he is on the hard (prime) tyre.
Di Resta continues to struggle, the Scot now spinning 360 at Turn 14. The Scot didn't run in yesterday's opening session, instead the car was handed over to reserve driver Nico Hulkenberg.
After yesterday's problems, the Renault duo appear to have rediscovered their confidence in the car. Heidfeld is currently fourth and Petrov sixth. With 22:30 on the lock, all but Liuzzi have been out.
While di Resta struggles, it's worth noting that he's quickest through the speedtrap at 192 mph, ahead of Rosberg, Sutil, Schumacher and the Renault duo.
Button takes the top spot with a 38.464 and no sooner has Alguersuari gone second (38.475) than Vettel posts 38.213 to go quickest. Buemi pops in a 38.665 to go third.
Schumacher is one of the first drivers, certainly the front runners, to switch to the soft rubber. The German posts a PB in the first sector, and again in the second finally crossing the line at 38.300 to go quickest. However, moments later, Vettel, on hards, posts 38.016.
Rosberg goes third with a 38.307, ahead of Button, Buemi, Barrichello, Alguersuari, Massa, Hamilton, Alonso and Heidfeld. These eleven are covered by 1.042s.
Alonso is back out on the softs, the Spaniard and his team really not looking too happy today. Massa is also on track, likewise on the softs.
Alonso goes quickest in S1 and again in S2. At the line the two-time champion posts 37.284, the first driver to dip into the 1:37s. While that might look impressive, there is no doubt that the Red Bulls and McLarens will have much more.
Massa posts PBs in the first two sectors while going quickest in the third, the Brazilian going second overall with a 37.762.
Interestingly, with 7:58 on the clock, Webber is still twenty-second, 7.071s off the pace, having completed twelve laps. However, we doubt if the Australian is unduly concerned.
Button (softs) goes quickest in S2 as Petrov goes quickest in S1. The Englishman goes quickest (36.805) as Alonso's second flying lap on the softs is well off the pace - the Pirelli drop-off or the weakness of the Ferrari package?
A 37.297 sees Petrov go third however, all eyes are on Hamilton who goes quickest in S2. Having maintained the pace, the 2008 world champion crosses the line at 36.340 to take the top spot from his McLaren teammate. Heidfeld posts 37.115 to go third, thereby pushing the Ferraris further down the timesheets.
Webber quietly takes second with a 36.630, though one suspects that Red Bull has yet to show its hand. Elsewhere, Liuzzi is on track and already outpacing his Indian teammate.
A poor final sector means Maldonado can only manage fourteenth however, all eyes are on Vettel. The German posts a PB is S1 and again in S2. At the line the world champion posts 37.175 to go fifth, having lost out to traffic.
The session ends with Hamilton quickest, ahead of Webber, Button, Heidfeld, Vettel, Alonso, Petrov, Massa, Kobayashi and Schumacher.
Rosberg is eleventh, ahead of Perez, Sutil, Maldonado, Buemi, Barrichello, Alguersuari, di Resta, Kovalainen, Trulli, D'Ambrosio, Glock, Liuzzi and Karthikeyan. Under the 107% rule neither Hispania would have made the cut.
While Red Bull and McLaren clearly lead the way - the Austrian team still to show what it is really capable of here - it's worth noting the improving pace of the Renaults.
Should be a fantastic qualifying session.
