One hour in and the times are slowly coming down as the track dries out as Carlos Sainz does a 1:35.226.

Lewis Hamilton started in the 1:39s but is steadily coming down as the track dries and is now in the 1:38s.

Image source, Getty Images

Plenty of spray kicking up as the cars circulate the track. Those tankers did a fine job.

There's a few more cars out on the track now, including the Mercedes with Lewis Hamilton now behind the wheel. He's out on inters.

Chris Medland
F1 journalist in Barcelona

Image source, Chris Medland

Don’t expect any fastest lap times for a while, as Pirelli has soaked the track using giant tankers to allow wet tyre testing to take place. McLaren are first to get out and try the conditions, which is a sensible call as the sun is trying to break through and it’s not too cold, so it might not take all that long to dry up again.

Daniel Ricciardo has switched to inters, which Nicholas Latifi is also out on. No other takers at the moment to test these wet conditions out.

Nicholas Latifi is back in the Williams with the plan, I believe for both himself and Alex Albon to get some time on the circuit this afternoon.

The seven-time world champion is yet to emerge, but surely won't be far off.

Daniel Ricciardo is out by himself on the wet track as the afternoon session gets under way. He's got full wet tyres bolted on.

Red Bull: Perez

Mercedes: Hamilton

Ferrari: Sainz

McLaren: Ricciardo

AlphaTauri: Tsunoda

Aston Martin: Stroll

Williams: Latifi/Albon

Alfa Romeo: Bottas

Haas: Schumacher

Image source, Getty Images

It was a stop-start session as we saw four appearances of the red flag. Fernando Alonso and Sebastian Vettel had the most dramatic stops with smoke coming off their cars.

Five minutes to go until the afternoon session begins and, like at football matches, the surface is currently being doused in water to create a wet session.

1. George Russell (Mercedes) 1:19.233 – 66 laps

2. Max Verstappen (Red Bull) 1:19.756 - 59 laps

3. Sebastian Vettel (Aston Martin) 1:19.824 - 48 laps

4. Charles Leclerc (Ferrari) 1:19.831 – 44 laps

5. Nicholas Latifi (Williams) 1:20.699 – five laps

6. Lando Norris (McLaren) 1:20.827 – 52 laps

7. Fernando Alonso (Alpine) 1:21.242 – 12 laps

8. Guanyu Zhou (Alfa Romeo) 1:21.939 – 41 laps

9. Pierre Gasly (Alpha Tauri) 1:22.469 – 40 laps

10. Alexander Albon (Williams) 1:22.652 – 21 laps

11. Nikita Mazepin (Haas) 1:26.229 – nine laps

OK I'll post the times from the morning session when I have them. There's a little break now for lunch before the afternoon session begins at 13:00 GMT.

The Russian Grand Prix, scheduled for 25 September, is off.