21/05/2015
NEWS STORY
Ahead of today's opening session, the air temperature is 14 degrees C, whilst the track temperature is 16 degrees. Following an overnight storm the track is still dampish and there is the prospect of further rain to follow.
Tyre options this weekend are soft and supersoft, the latter, which features a new compound, making its 2015 debut. There is one DRS zone, and that's on the pit 'straight'.
This being Monaco, the risks being what they are, there are no third drivers or reserves on duty this morning.
While Lewis Hamilton will be keen to celebrate his new Mercedes deal with a win, teammate Nico Rosberg would love to take his third successive victory here, closing the title gap in the process.
This is a circuit where anything can happen - and usually does - in terms of the weather and the Principality's unique micro-climate and the ability to throw up shock results.
Due to the remaining damp patches, the session has been declared 'wet', though the sun, which has magically appeared, is doing its job and the storm residue is evaporating.
A late ERS issue is likely to limit Button's running this morning.
The lights go green and Ericsson leads Raikkonen and Bottas down the pitlane, all on Inters.
Most complete the sole installation lap, though Maldonado, Rosberg, Hamilton and Grosjean stay out for a second lap. Indeed, the Mercedes duo posts times, Hamilton crossing the line at 1:27.842 and Rosberg 33.180.
Despite being the only drivers on track, the pair are running remarkably close together.
Just six minutes in and everyone bar Button and the Manors have been out. The Yorkshire team making an emotional return here.
The two Manors emerge, whilst following a quick stop, Hamilton is also back on track, as is Rosberg, both now sporting the prime tyres. The Briton improves to 23.992.
More and more drivers return to the track, most following the Mercedes example and switching to primes. Ericsson goes third (36.150), only to be eclipsed by Ricciardo (26.987) and Verstappen (32.593).
Complaining of "abnormal rear locking", Sainz runs wide at Ste Devote.
Rosberg clouts the barrier at Tabac and heads into the pits, it's hard to tell if he incurred damage. Hamilton improves to 22.103.
As Vettel overtakes a Manor, Nasr gets it wrong at Ste Devote. Indeed, it's like Sunday afternoon for Vettel as he finds himself having to weave through the traffic.
Bottas is the latest to get it wrong at Ste Devote, a corner which has claimed so many over the years.
"I have no front warm-up whatsoever," complains Raikkonen. Nonetheless, he goes third, behind Hamilton and Ricciardo, with a 2..079 before improving to second with a 22.238.
Back to Ste Devote, where Ricciardo is thankful of the run-off, the Australian doing a quick reverse job and returning to the fray. Moments later it's Alonso's turn.
McLaren reveals that the crew is aiming to get Button on track "before 10am".
The 'free' half-hour comes to an end, Hamilton heads Raikkonen, Ricciardo, Vettel, Maldonado, Sainz, Perez, Grosjean, Verstappen and Hulkenberg.
While the rest return to the pits, Rosberg heads out on a brand new set of primes, thus enjoying a completely empty track, a rarity in Monaco.
Making full use of the free air, Rosberg improves to third with a 22.449, still 0.827s off his teammate's best. It's in the two final sectors where he's losing out.
That said, a 21.744 sees him close to within 0.122s of his teammate.
A 20.700 sees the German go quickest by almost a second, but Hamilton is back on track. Moments later the Briton posts 19.764. Rosberg responds with a 19.762. Game on!
Indeed, Hamilton bangs in a 19.196, over half-a-second quicker than Rosberg. Remember, this is where it all began to sour for the Mercedes pair last year.
Shortly after Stevens gets it wrong at Ste Devote, Ricciardo makes another short visit to the escape road.
As Button looks ready to come out and play, attention switches to his teammate's car.
Sainz improves to fourth with a 22.106, it make it a Toro Rosso 3-4. Moments later the Spaniard has a massive lock-up.
Kudos to the McLaren crew; five minutes before scheduled time, Button heads down the pitlane.
As flo-vis is applied to the front wing of Ricciardo's car, Vettel posts 20.444 to go third.
Another improvement from Hamilton sees the Briton open a 1.012s gap to his teammate.
As Raikkonen improves to fourth, Maldonado is off at Mirabeau, the 'corner' at the centre of all the controversy last year.
Vettel splits the Mercedes with a 19.382 but remains 0.632s off Hamilton's pace. The German subsequently does very, very well to keep it out of the barriers in Casino.
As Alonso improves to thirteenth (21.662), teammate Button is back in the pits having completed a single installation lap.
More problems for Vettel as he locks-up and consequently misses the chicane exiting the Swimming Pool. However, he subsequently improves with a 19.134, thereby closing the gap to 0.384s.
Back on track, Button reveals that "there appears to be a limiter in fourth and fifth gears".
Massa improves to fifth with a 20.175. Up to now Williams has been giving away very little in terms of revealing its potential pace here.
As Button is told to pit, Alonso improves to seventh with a 20.262, the Spaniard subsequently locking-up big time at the Nouvelle Chicane.
Bottas, having overdone it at Ste Devote, performs a neat little pirouette and gets going again.
Another improvement from Alonso, the Spaniard going fifth with a 19.791. Teammate Button is currently nineteenth (25.890). Alonso is subsequently bumped down to sixth when his former Ferrari teammate, Massa, posts 19.766.
As ever, focus now switches to Sunday with cars on longer runs, some on full fuel.
A lock-up for Hamilton sees the Mercedes driver miss the chicane exiting the Swimming Pool. Raikkonen has been told that the Briton is on a high fuel run - the Finn on a similar strategy.
Hamilton complains about his dashboard display, claiming that some of the colours have been changed.
Maldonado's Lotus looks extremely skittish at various points on the circuit.
Verstappen, making his Monaco debut, goes third with a 19.365.
Kvyat is told to "calm down" after swearing at the time he is losing behind slower cars.
With five minutes remaining, all but Alonso are on track.
A 19.311 sees Ricciardo go third, the Australian subsequently going quickest in the first sector of his next lap. Indeed, he crosses the line at 19.086 to go second, 0.336s off Hamilton's pace.
As the track continues to improve, drivers post PBs in various sectors.
As the chequered flag is waved, Verstappen goes second with an 18.899, teammate Sainz going fourth moments later. A late, late improvement from Maldonado also.
Hamilton is quickest, ahead of Verstappen, Ricciardo, Vettel, Sainz, Maldonado, Kvyat, Raikkonen, Rosberg and Massa.
Alonso is eleventh, ahead of Button, Grosjean, Perez, Hulkenberg, Nasr, Bottas, Ericsson, Stevens and Merhi.
Check out our Thursday gallery, here.