Ahead of today's second session the air temperature is 21 degrees C, while the track temperature is 32 degrees. Since FP1 the sun has disappeared and now there is even talk of a 40% chance of rain.

Sainz was the pace-setter, edging out teammate Leclerc, Perez and Verstappen is a session that witnessed two red flags. The first was to retrieve a piece of bodywork from the track while the second was due to Vettel stopping with an engine issue.

Incidentally, the German, ho has had an engine change during the break, is under investigation for returning to the pits on a scooter having used the race track as opposed to the escape road network.

Other than that there were no significant incidents other than a couple of cases of impeding.

The lights go green and the Alfa pair lead the way, with Zhou hot on the heels of teammate Bottas. Stroll is next out, followed by Norris and Ocon.

At Red Bull a new floor is being fitted to Verstappen's car.

Bottas gets proceedings underway with a 22.410, while Zhou responds with a 23.358.

No sooner has Norris gone quickest (21.852), than Ricciardo posts a 21.793.

Just 5 minutes into the session and we have a traffic jam in the final sector as drivers seek to create a space.

Leclerc goes quickest (20.898) ahead of his Ferrari teammate who stops the clock at 21.145.

Stroll in under investigation - and rightly so - for impeding Sainz, the Canadian having 'parked' his car on the racing line in the final corner as he sought to create a space.

All bar Vettel, Perez and Schumacher are on track, mostly on mediums though a few are on hards.

A 20.432 sees Bottas go top as Stroll is also noted for impeding Hamilton.

A hairy moment in Turn 1 for Russell who goes over the kerb and almost loses the rear of the W13. The Briton is currently 13th.

Quickest in the first and final sectors, Sainz goes quickest with a 19.979 on mediums.

"The car feels much better," says Albon, though he is still struggling with "mid-corner over-rotation".

"I still have the same issues, I can't turn the car in," reports Verstappen.

Schumacher spins at Turn 11 which briefly brings out the yellows, at which point drivers begin making the switch to softs.

While Sainz has to abort his flyer after encountering a very slow Tsunoda, Leclerc goes quickest with a 19.711 despite a mistake in the final sector.

Making up for his previous error, Sainz stops the clock at 19.568 to retake the top spot.

Norris improves to third (20.100), ahead of Bottas, Gasly and Alonso as the Finn goes cross-country at Turn 1 after locking-up and being unable to make the corner.

Down in 11th, Ocon goes quickest in S2 but fails to improve his overall time.

Moments later, Alonso also goes quickest in S2, finally crossing the line at 19.537 to go top.

The Spaniard's glory is short-lived however, as Leclerc posts a 19.376.

In quick succession, Latifi is off at Turn 6 and Hamilton at Turn 8.

Verstappen improves to fourth (19.812), but the Red Bull doesn't look anywhere near as stable as the Ferrari.

Indeed, having gone quickest in S2, the Dutchman is a little too ambitious in the final corner, locks-up and ruins the lap.

With 18 minutes remaining, Aston Martin announces that "despite the team's best efforts", Vettel's car will not be ready to run in this session.

Verstappen splits the Ferraris with a 19.223, but remains 0.245s off Leclerc's pace.

Attention now switches to Sunday afternoon, with long runs on high fuel.

At which point the session is red-flagged when the 'wheel brow' from Stroll's front left fells from the car.

The session resumes with 9 minutes remaining, Tsunoda leading the way.

"All the cars reporting graining on the medium compound," Leclerc is advised.

All bar Vettel are on track.

On board with Leclerc and the Ferrari driver is tasking a real pounding courtesy of the car's porpoising.

"I've got a lot of air in the cockpit around my legs, is everything okay?" asks Leclerc. "We are not sure what it is," he is told, "it is not anything wrong at the moment," he is assured.

The session ends. Leclerc is quickest, ahead of Verstappen, Sainz, Alonso, Perez, Ocon, Bottas, Norris, Gasly and Ricciardo.

Russell is eleventh, ahead of Tsunoda, Hamilton, Stroll, Zhou, Magnussen, Albon, Schumacher, Latifi and Vettel.

Check out our Friday gallery from Melbourne, here.