Ahead of today's sole practice session, the air temperature is 12 degrees C, and the track temperature is 20 degrees. Following overnight rain - how do you think this place gets to look so green, so lush - it is still damp and heavy cloud suggests we are in for more of the wet stuff today.

Sebastian Vettel was quickest in the second session yesterday, but separate (unrelated) gearbox issues in both sessions cast a shadow over the German's hopes. That said, until he destroyed a set of tyres, teammate Kimi Raikkonen was looking very good, confirming speculation that Ferrari will be strong here.

Nico Rosberg led a Mercedes 1-2 in FP1 but in all honesty his teammate doesn't look too comfortable hear. Unable to (his words) "get near" Rosberg's pace, the Briton snapped at his crew over the radio.

Truth be told, all the Mercedes powered runners look strong here, and while both Williams runners were well down the timesheets their long run/high fuel pace was very good.

Red Bull is facing a difficult weekend, which is why, this being its home race, the Austrian outfit's management is laying into the sport's powers-that-be, in an effort to distract attention. With the team changing the power units in both cars it is likely Ricciardo and Kvyat will be joining the Manors and McLarens at the rear of the grid.

Despite an updated engine and various updates for the car, Fernando Alonso admits that this weekend will be seen as a prolonged test session rather than a race. Fact is, each weekend brings a raft of new problems for the Woking team and its engine partner, which is still trying to come to terms with the issues raised over previous GP weekends.

Indeed, in a late move McLaren has changed the entire unit in Jenson Button's car meaning the Briton takes a 25-place grid penalty. The fact that there are only 20 cars on the grid gives you some of idea where the sport is these days.

Courtesy of a green track and low temperatures there were incidents aplenty, with everyone running wide at some point or another, turns 1, 8 and 9 proving to be the main trouble spots, though drivers were having problems at T3 also. That said, not a single red flag. However, that might change today as the pressure mounts and pace increases.

With a 40 percent chance of rain it is likely we'll see action from the start. However, with qualifying in just a couple of hours, and a dry race likely, nobody will want to take any unnecessary chances.

The lights go green and Merhi gets things underway. The Spaniard is soon joined by Grosjean, Raikkonen, Button, Stevens, Maldonado and the Mercedes pair.

Stevens posts the first time of the day (18.078) but this is soon eclipsed by Rosberg who posts a much more sensible 12.469. Hamilton can only manage 15.062.

It was a marmot a couple of weeks ago in Canada, today it's a hare that opts to join in the fun.

Next time around, as Nasr complains of "some smoke coming out", Hamilton goes quickest in all three sectors, crossing the line at 11.131. Maldonado improves to second with a 11.383, Rosberg failing to improve after a lock-up in T1.

Sainz warns that there are "spots of rain in sectors 1 and 2".

A 10.358 sees Hamilton go quickest again, as Maldonado runs wide in T1 after a massive lock-up.

On his first flying lap, Vettel goes straight to the top of the sheets, the German stopping the clock at 9.994, that's 0.261s clear of Hamilton.

Perez runs wide after picking up a puncture during an earlier excursion, as Verstappen, who had a torrid time yesterday, goes fourth (10.826).

Hamilton improves but is unable to beat Vettel's best, as Raikkonen posts 10.781 to go fifth.

Kvyat locks-up in T1 and is left with a large flat-spot as a result.

Raikkonen improves with a 10.177 to third, the top three covered by just 0.183s.

Like yesterday, Hamilton looks ragged, pushing too hard. Quick in the first two sectors he throws it all away in the third.

As Massa goes fifth (10.408), Grosjean complains of problems with his clutch, the Frenchman is told to stay in current gear and pit.

Both Mercedes lined up behind one another outside their garage as the drivers perform practice starts. Rosberg isn't too sure about the idea:; "What am I doing," he asks.

After twenty minutes, it's: Vettel, Hamilton, Raikkonen, Rosberg, Massa, Bottas, Verstappen, Grosjean, Hulkenberg and Maldonado.

Ericsson is told that the chance of rain in the next fifteen minutes is "relatively big".

Alonso is the first to make the switch to option (supersoft) rubber. Thirteenth (no comment) on 11.168 the McLaren driver fails to improve over the next couple of laps.

Grosjean, who had pitted, slowly makes his way back to the pits, the Frenchman unable to "get a gear".

More and more driver switch to the options, as Ricciardo is warned that rain is expected.