While the rain stopped falling for the final ten minutes of this morning's practice session it began falling again shortly after and has been intermittent ever since.

Though this session is expected to take place in changeable conditions, tomorrow is expected to be fine. Which makes things all the more difficult for the drivers and their engineers - but all the more exciting for us.

Fifteen minutes before the start of the session, Bob Constanduros texts: "It's spitting a tiny bit, the track is wet, quite bright outside with clouds clearing. It's going to be all about being out there at the right time, probably the end of the session when it's at its driest in each case."

Five minutes before the session is due to get underway, Martin Whitmarsh reveals that though it has now stopped raining his experts predict that there will be a further downpour just five minutes into the session. Shortly afterwards, Ross Brawn says he is expecting rain halfway through the session.

As the lights go green signalling that start of this all-important session the air temperature is 19 degrees C while the track temperature is 25 degrees. Humidity is 84%.

To add to their problems, Sutil and Buemi both have 5-place grid penalties carried over following their naughtiness in Korea.

Buemi heads a queue of around ten cars at the end of the pitlane, all eager to get out there and get in that all-important 'banker' lap. Indeed, within seconds all twenty-four drivers are on track. The spray is one thing, the traffic quite another.

Buemi crosses the line at 1:22.744, the Swiss, unlike his rivals, enjoying a free track and no spray. On their first lap, only Webber and Massa are able to beat the Toro Rosso driver's time, the Australian going quickest with a 21.272.

A number of drivers run wide at various points on the track, including both Force Indias. Indeed, Liuzzi and Sutil almost take one another out.

Hulkenberg goes quickest only to be beaten by the wily old rain-master, Schumacher, who posts 20.940.

Hulkenberg re-takes the top spot with a 20.537 as Barrichello makes it a Williams 1-2 with a 20.848.

No sooner has Webber posted 19.950 than Vettel sneaks in a 19.855 to take the top spot. Hamilton is warned that rain is coming and that he must be careful for the next few laps. At this stage it is the usual suspects that fill the bottom six positions - no major upsets.

Alonso goes quickest in S2, finally crossing the line at 19.842 as Heidfeld drops into the danger zone.

Next time around Alonso goes quickest again in S1 but the rest of his lap is poor, while Rosberg, who is also quick in S1 runs wide and ruins his lap.

Having gone quickest in S2, Vettel is quickest again in S3 crossing the line at 19.160 to go quickest. Hulkenberg is on a hot lap, posting a 20.050 to go fifth. Elsewhere, Alonso is warned that rain is imminent.

Buemi, currently sixth, goes quickest in S1 however, he's off the pace in the final two sectors and fails to improve. Elsewhere, Alonso has moments when he hits the white lines at Tune 11.