Ahead of today's opening session the air temperature is 29 degrees C, while the track temperature is 41 degrees.

This morning, much like FP3, is pretty much unrepresentative due to the fact that qualifying and the race take place in the evening when it will be cooler.

However, with only one driver (Sergio Perez) having experience of the track, this morning will be invaluable in getting use to the track.

There are no support races at all on the schedule and the circuit hasn't been used a lot recently, which will mean that there's no rubber laid down prior to the cars running this morning. As a result the drivers can expect a slippery track at first and a high degree of track evolution. The surface could also be 'reset' by sand blowing onto the track over the weekend.

Indeed, in the minutes before the start of the session there is sand being blown on to the track and what appears to be a dust storm in the distance.

All things considered, it is understandable that Pirelli has gone for the hardest compounds in its range.

Such is the lack of information on the track it is understood that the various teams simulations vary by more than 5 seconds in terms of what sort of pace we can expect here.

As ever, track limits are being enforced with no less than 5 corners - 4, 12, 13, 14 and 16 under scrutiny.

The lights go green and Raikkonen leads the way, followed by the Haas pair.

More and more drivers head out, among them the Ferrari duo and Bottas, while Ocon is on softs the rest are running a mixture of hards and mediums.

Due to an "awkward drain", Schumacher is told not to wheelspin when exiting his garage.

As Hamilton heads down the pitlane, Raikkonen has the honour of posting the first time by an F1 car, the Finn crossing the line at 1:30.173. Ricciardo responds with a 29.192.

Leclerc warned of a 15 km/h headwind into Turn 1.

Hamilton posts a 29.573, Verstappen 26.829 and then Ricciardo a 26.727 as the drivers familiarise themselves with the track. Bottas goes third with a 26.870.

"I feel massively down on power," says Hamilton.

With almost every lap the bar is lowered, Sainz, Gasly... while Verstappen, quickest in all three sectors, bangs in a 25.669.

No sooner has Bottas posted a 25.231 than Norris crosses the line at 25.215.

Like his teammate, Alonso is on the red-banded rubber.

Verstappen goes top with a 24.998 as Perez complains of someone (inaudible) being "far too aggressive into Turn 1". "Yes, we saw that," he is assured.

As Hamilton improves to 25.360, Verstappen ups the ante with a 24.855.

"That slow lap may have been a bit too slow," Hamilton is advised.

Incidentally, Verstappen is on hards, as are the Mercedes duo, while Norris, Gasly and Leclerc are on mediums.

Seventh placed Ocon is on softs.

A number of drivers, including Hamilton and Norris are finding it difficult to keep it on the black stuff, which could be an issue once the stewards begin to crack down.

"Biggest issue is rear entry to the slightly more medium and high speed corners," advises Norris. HE subsequently pits.

Sparks and dust fly as Gasly runs wide at Turn 3.

Thirty minutes in and the drivers begin switching to the red-banded rubber. Bottas is the first of the big guns to make the switch.

Giovinazzi almost heads off into the desert as he runs wide, while Stroll reports "brake failure".

On the softs, Vettel improves to 4th with a 25.328.

"Don't shift, don't shift," Stroll is told, "there is a hydraulics issue, drive slowly."

Tsunoda (softs) goes quickest with a 24.648, but Bottas responds with a 24.194. The Finn went wide at a number of corners but without sanction.

"Understeer in seven, the rest is more on the nose," reports Vettel.

No sooner has Hamilton gone second (24.509), than Verstappen bangs in a 23.723.

All are currently on softs, bar Perez (hards) and Gasly (mediums).

Sainz is the latest to go wide, however in many cases it is not merely a case of going over the white line it is going some considerable way off track.

"Something's gone wrong," says Norris as he enters the pitlane very, very slowly. Replay shows him taking a very bumpy ride over the kerb at Turn 15.

Having gone quickest in S2, Hamilton subsequently eases off following a mistake.

With the stewards seemingly turning a blind eye to track limits for now, drivers continue to push the limit. However, the crackdown is sure to come and certain drivers appear to be lulling themselves into a sense of false security.

Turn 14 is proving to be particularly difficult, most notably for Hamilton.

"How's the final sector looking until the last corner," asks the world champion. "It better," he is told, "but still too much speed into Turn 14."

Back in his garage, following a call from his team, the Mercedes crew form a wall as work is carried out on what appears to be a broken front wing for Hamilton. No doubt kerb damage.

Vettel pits after reporting something loose around his feet.

Verstappen is back on track, as is Norris, while Gasly finally switches to the softs.

"We are strong at high speed but losing a little at 16," Gasly is told.

As Schumacher goes off (Turn 7) into one of the rare gravel traps here, the yellow flags are waved as a piece of debris is removed from the middle of the track. "Sorry about that," he apologies. Incidentally, the stones in the gravel trap are huge.

Meanwhile, as late improvement sees Gasly go second, 0.437s off the pace.

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

Ricciardo is eleventh, ahead of Vettel, Latifi, Giovinazzi, Raikkonen, Russell, Alonso, Schumacher, Stroll and Mazepin.

Though unrepresentative it was an interesting session, if only to see the job the stewards and the drivers have on their hands in terms of track limits.

Certainly, we have seen a number of cars incur damage this morning, with Alpine Marci Budkowski admitting that front wings, floors and bargeboard, anything that touches, as susceptible.

Check out our Friday gallery from Qatar, here.