Ahead of today's second practice session the air temperature is 15 degrees C, whilst the track temperature is 20 degrees. It is somewhat overcast with a few drops of rain in the air.

Though the threatened rain didn't really affect FP1, a "significant" spillage of diesel did, the session reduced to just sixty minutes as marshals cleared the mess and subsequently allowed it to dry.

Consequently, and no disrespect to Nico Hulkenberg who topped the timesheets, the order and times set were of little significance.

Indeed, as speculation over Red Bull's future continues, activity in the various team hospitality units totally overshadowed what was happening on track.

There are two DRS zones, the first on the pit straight and the second on the long sweep between T10 and T13. Tyres, like Singapore and other street tracks, are soft and supersoft, a step softer than in 2014.

Having given his car over to Jolyon palmer for FP1, Romain Grosjean is back in the Lotus this afternoon.

As the lights are about to turn green the heavens open, and the mass of dark clouds filling the sky suggest were in for more of the same over the next ninety minutes.

"Track is green but no cars have ventured out as yet," tweets Mercedes, "may be a slow session unless the rain stops".

After twenty minutes of total nothingness, Vettel heads down the pitlane, his Ferrari sporting full wets.

Whilst we never thought we'd find ourselves comparing this circuit to Spa, just like that magnificent venue some parts of the circuit are dry and others wet.

Vettel completes his exploratory lap and heads straight back to the pits where he performs a practice start and heads out again. He is subsequently joined by Alonso, two drivers, six titles.

"From turn thirteen to turn two, there is quite lot of standing water," reports Vettel, then to two to thirteen it is only damp."

After another ten minutes of total inactivity, an engine fires up and Alonso heads out once more.

Despite a couple of twitches, Alonso posts the first time of the afternoon, crossing the line at 2:05.599.

Bottas is next out, like Alonso he is on the full wets.

As Bottas spectacularly slithers his was around the Sochi Motodrom, Alonso gets down to 2:02.414, then 2:01.077. The Finn heads back to the pits.

With forty minutes remaining, and just one time posted, Rosberg heads out. With no rain forecast for tomorrow or Sunday, most teams clearly see no point in completing any significant running.

Rosberg heads back to the pits whilst a minor mistake by Ericsson brings out the yellows. Moments later Hamilton heads out.

"Conditions are not very representative," says Force India, explaining its reticence to go out. That's the phrase we were looking for; "conditions are not representative".

"Kerbs are slippery," Hamilton is warned, "last part of the circuit is particularly wet."

Sainz and Verstappen head out as Hamilton heads to the pitlane for a practice start.

Sainz does well to keep it under control through a very wet T13. He crosses the line at 2:05.973, the youngster pushing all the way.

Sadly, having brightened up, a little, the skies have now darkened again and the rain appears to be falling again. That said, Verstappen posts 2:02.642.

"There's no chance it is going to dry up in the next twenty-five minutes," Ericsson is told. "I think it is useless to run."

On the other hand, Verstappen improves to 2:00.806.

Perez and Hulkenberg head out, subsequently joined by Button.

"We have heavy rain on this side of the circuit," Hulkenberg is warned, the German subsequently diving into the pits.