Ahead of today's sole free practice session, the air temperature is 14 degrees C, while the track temperature is 15 degrees. Just ten minutes before the start of the session the first spots of rain began to fall, though the track was already wet from heavy overnight downpours. What's more, it's unusually cold.

If yesterday's session didn't give us much information, we might be in for some more of the same today. That said, the order appears to be the same as ever, Red Bull, McLaren, Ferrari and the rest.

While we all adore this majestic track and have got used to its quirky microclimate there are times when the constantly changing conditions are more than a little frustrating.

The big news this morning is that Mark Webber has signed a new one-year deal with Red Bull, the ideal way to celebrate his birthday. Also, talking of Australians, the ideal wake up call for Daniel Ricciardo who, at this stage, must be considered a shoo-in for the Austrian team in 2013.

Moments before the session is due to get underway, 1964 world champion John Surtees poses for photographers in the pitlane with Fernando Alonso and Felipe Massa. The Englishman won here in 1966.

When the lights go green local hero Jerome d'Ambrosio is the only driver to venture out, the clouds over the circuit various shades of very dark grey and black.

Although the rain is light it is very wet out there. A number of teams predict heavier rain later in the session and further showers this afternoon.

While d'Ambrosio is on inters, Perez is on wets. As more and more drivers take to the track, including the Mercedes and Red Bull duos, most of them are on full wets.

Five minutes into the session all but Button and Ricciardo have been out. On board camera picks up the fact that Hamilton is aquaplaning on a couple of parts of the track. The Englishman was lucky to escape a major off at Blanchimont in yesterday morning's session. "It's massively wet," he tells his crew.

After ten minutes of total inactivity an engine fires up. And then the silence returns when it is cut.

Mike Gascoyne says it is unlikely there will be much running for the foreseeable future, a claim endorsed by McLaren. Every now and then an engine is fired up, raising anticipation in the grandstands, only to be frustratingly switched off again.

Twenty-one minutes into the session, Daniel Ricciardo finally comes out for his installation lap. Unsurprisingly he is on full wets.

As the Australian returns to the pits, Alguersuari is the first driver to come out for a second run, followed, a minute later, by his Toro Rosso teammate and, subsequently, Vettel.

Alguersuari crosses the line at 2:30.210 as Vettel begins his first flying lap. Buemi posts a 2:14.207.

Vettel isn't pushing too hard, crossing the line at 2:15.082 as Perez, Petrov, Senna and Maldonado come out to play.

Senna gets it all wrong at Les Comes and has to work his way around the various barriers. Elsewhere, Webber posts 2:14143 to go quickest, ahead of Buemi, Alguersuari, Vettel, Trulli, Maldonado and Kovalainen.

The rain has stopped but it is still very, very wet. Furthermore, Ferrari claims there will be another "shower" some time soon. Mercedes reveals that Schumacher has asked if anyone has been out on inters yet. The answer is no.

Di Resta goes off at Pouhon after losing grip on the kerbs - which have been freshly painted red and yellow in deference to the race sponsors (Shell).

Ass Buemi goes quickest (2:13.306), all but Alguersuari, Webber, Trulli, Schumacher, Hamilton and Button are on track. With rain expected this afternoon, drivers have to ensure they keep enough sets of tyres.

Sutil takes the top spot with a 2:13.231 as Buemi says it will soon be OK to make the switch to inters. At which point the camera cuts to Schumacher who has already made the switch. The board coverage makes it clear that there are still a number of points where he's aquaplaning. To add to his problems, the German appears to have a problem with rain water trapped between the rip offs on his visor.

The German's bravery is rewarded when he takes second with a 2:13.199. Moments later, di Resta, on wets, posts 2:12.955.