Ahead of today's sole free practice session the air temperature is 19 degrees C, whilst the track temperature is 21 degrees.

As forecast, it is wet. Indeed, it is very wet. There was heavy rain earlier and whilst it has now eased the circuit remains very wet and there will be further heavy rain throughout the day... including during qualifying.

However, with dry conditions predicted tomorrow this will make things difficult for the teams and should certainly lead to the sort of 'mixed up' grid Mr Ecclestone has been calling for.

Indeed, with Lewis Hamilton already carrying a 5-plane grid penalty, the Briton cannot afford any mishaps during this afternoon's session.

Nico Rosberg was quickest in yesterday's opening session, whilst Kimi Raikkonen led a Ferrari 1-2 in FP2. However, all that goes out of the window in these conditions.

The problems that punctuated FP1 have now been traced to a suspension failure for Kevin Magnussen and a set-up issue related to new vanes in the rear brake ducts on Felipe Massa's Williams.

It was a difficult days for Haas also, Esteban Gutierrez suffering a brake fire in the morning and teammate Romain Grosjean suffering numerous issues.

Whilst the wet conditions will level the playing field and possibly allow teams like McLaren to shine, the fact that it will almost certainly be dry tomorrow means that it will paint a false picture.

As expected, when the lights go green, signalling the start of the session, there is no sign of anyone going out. Far from it, nobody appears to be sitting in their cars. Other than the fact that conditions will be different tomorrow, there is also the risk of damaging the car in these conditions.

Fifteen minutes into the session and Bottas is the first driver to head out. Shortly after he is followed by his Brazilian teammate.

A nasty wobble for Bottas as he returns to the pits, his place on track now taken by Palmer, Button, Magnussen and Alonso.

"Radar looks clear," Alonso is told, "so no more rain for the moment."

More drivers pour (sorry) on to the track, amongst them Grosjean who spins at T10 momentarily bringing out the yellow flags. Shortly after, Kvyat runs wide.

Hamilton is among the last to make an appearance, as we await Vettel, Ericsson and the Toro Rosso duo.

Approaching the half hour, Massa and Magnussen are the first drivers to come out for a second run.

One driver who appears to be revelling in the conditions is Raikkonen, who fights his Ferrari all the way, posting the first time of the day (2:00.812). Moments later Massa posts 2:02.438.

Bottas goes second (2:01.256) as Palmer returns to the pits with a (rear-right) puncture. Elsewhere, Magnussen takes a long, long detour after running wide in T1.

Kvyat, the first driver to switch to Inters, runs wide in the final corner. No such problems for his teammate, also on Inters, who goes quickest in the first two sectors before heading into the pits.

With twenty minutes remaining, Vettel heads out, as do the Toro Rossos.

On full wets, Sainz posts 59.865 to go quickest.

"A couple of times now we've got issues," complains Vettel, "stuck in first gear."

Hulkenberg (Inters) goes second with a 2:00.158.

Despite his issues, Vettel posts 57.351 to take the top spot, though currently there are only nine time on the board.

Informed he has lost telemetry, Grosjean is told to "box".

Perez posts 58.689 to go second.

"Qualifying is also likely to be held in wet conditions, so teams will not want to use too many inters and wets during FP3. Just in case," Pirelli reminds us.

With twelve minute remaining, more drivers switch to Inters.

Raikkonen almost trips up over Nasr who had just run wide. The moment causes the Finn to abort his lap and head back to the pits.

Onboard footage shows Wehrlein struggling for grip. The German is currently ninth.

Bottas posts 58.061 to go second, just 0.710s shy of Vettel's best.

Back on track following his puncture, Palmer runs wide in T6.

"The balance is absolutely rotten," claims Wehrlein, "so much understeer." Nonetheless, he has improved to seventh (59.964).

Palmer goes sixth with a 59.677 as teammate Magnussen goes seventh (59.761) moments later.

With less than two minutes remaining there are only three drivers on track, only 14 names on the board. One of those three drivers on track is Ericsson... who will at least complete a lap or two.

Magnussen has completed the most laps... 9.

The session ends, Vettel is quickest, ahead of Bottas, Perez, Sainz, Gutierrez, Palmer, Magnussen, Wehrlein, Verstappen, Hulkenberg, Nasr, Raikkonen, Massa and Haryanto.

While Hamilton, Rosberg, Ricciardo, Kvyat, Ericsson, Alonso, Button and Grosjean all failed to post times.

Check out our Saturday gallery, here.