A snap of oversteer into Turns 2 and 3 from Lando Norris as he embarks on his slicks experiment.

He's already two seconds down on current leader Lewis Hamilton in the first sector.

Well Lando Norris, the championship leader, is the first man on slicks during this session.

"Zero risk" he's told over the radio.

Goes without saying!

Hardly any one's out on track at the minute.

Given there's the potential for rain, surely no one's mad enough go go out on slicks?

Rain could be on the way, apparently.

That would certainly mix things up and might even have a say on qualifying.

Lewis Hamitlon's having a decent session in his Ferrari so far.

His 1:42.809 is currently the time to beat.

Image source, Getty Images

"Box this lap, we've got an issue with the car."

1. Lando Norris (McLaren) 1:43.078

2. Lewis Hamilton (Ferrari) +0.059

3. Oscar Piastri (McLaren) +0.131

4. Max Verstappen (Red Bull) +0.699

5. Liam Lawson (RB) +0.975

Alice Powell
British racing driver on BBC Radio 5 Sports Extra in Las Vegas

One thing here that makes it difficult to run that low downforce is the temperatures, it's a lot colder.

Also the bumps, in particular down into Turn 14, the drivers will be hitting the brakes at over 200 miles per hour at the end of that Strip.

It's bumpy and the grip surface is low, the tyre temperature is not going to be where you ideally want it.

Lando Norris goes fastest with a 1:43.078, just ahead of Lewis Hamilton who's just 0.059 seconds behind.

Oscar Piastri is currently the fastest man on track.

He's set a 1:43.896 in his McLaren, 0.618 seconds faster than Lewis Hamilton in second.

Those lap times are beginning to come down. Who's going to go out on slicks first then?

Rosanna Tennant
5 Live F1 reporter in Las Vegas

It's nice to see cars on track, there are quite a few people in the grandstand on the start-finish straight so they're being treated to some action.

I'm not seeing any rain on the radar, is it just worth the drivers going out to clean up the track because it takes so long for the circuit to dry?

"It's almost dry. Almost ready for slicks."

That quick corner out of Turns 14 and 15 look fun.

Carlos Sainz avoids the wall as he drifts through them. Meanwhile his Williams team-mate Alex Albon takes the runoff area at Turn 5 to avoid a high speed meeting with the wall.

Max Verstappen, who won the first race here two years ago, does incredibly well to avoid going into the wall.

His rear was drifting in the wrong direction at a high speed corner. Meanwhile Lando Norris also does well to keep on the straight and narrow.

It's difficult out there at the minute as the track's so variable.

Alice Powell
British racing driver on BBC Radio 5 Sports Extra in Las Vegas

What Oscar Piastri was talking about there is basically the surface of his intermediate tyres have got too hot and when it meets the dry part of the track it just starts to bubble over and the grooves start to fold over.

You then do not have the grip and that is what we were kind of expecting.

The track certainly feels like it's in a state of flux at the minute and will dry quite quickly.

This is the place to gamble after all so you do wonder who's going to stick a set of slicks on first and whether they'll prosper.

"Tyre is starting to die already but I would be very nervous on the slicks."

Image source, Getty Images

The track looks a bit patchwork between dry spots and wet and there's not a clear racing line just yet.

Oscar Piastri slipslides his McLaren over the line with a time of 1:47.162.

Alice Powell
British racing driver on BBC Radio 5 Sports Extra in Las Vegas

There's so many variations of tarmac here and painted white lines on the circuit.

This straight now that Lewis Hamilton is heading down which goes into Turn 10 is pretty damp.

The drivers are desperately out there to try and make sure they're getting some data in, but it's going to be so tough to generate that tyre temperature because it's so cold.

"At the moment it's too wet for slicks"