Sam Bird
Formula E driver on BBC Radio 5 Sports Extra

If we are looking at the times now everyone has had a decent stint on the intermediate tyre. The Mercedes look like the car that have raised their game in these kind of conditions.

Is it spitting? Or is this the start of a proper downpour? We still have nine cars delighting the fans out on the circuit but we haven't seen any frighteningly fast speeds just yet.

Marc Priestley
Former F1 mechanic on BBC Radio 5 Sports Extra

The rain is coming down sideways such as the wind around this place.

That wind affecting the aerodynamics of the car depending on the angle it's blowing at you coming into a corner can dramatically change how you approach these turns.

Weatherman Max Verstappen is having a difficult time getting those intermediate tyres up to standard and his latest lap sees his Red Bull dice with the gravel with a rear wheel. The Dutchman is in fifth place on the timesheets behind the Carlos Sainz, Lando Norris and the two Mercedes of Lewis Hamilton and George Russell.

Jennie Gow
F1 pit-lane reporter

It's raining in the pit-lane as George Russell just goes out, the other Mercedes [of Hamilton] has gone out already.

The little graphic on the official timing screen is informing us of rain trackside, but there are still plenty of cars completing their Saturday run plan. Max Verstappen tells his pit wall it is indeed raining and is met with a "yeah, we're aware of that, box" reply.

Pierre Gasly finished with a point at the Austrian Grand Prix but repeating that achievement will be a tough task for the Frenchman this weekend.

The Alpine driver is set to drop to the back of the grid at Silverstone - wherever he ends up qualifying this afternoon - after the team changed a number of power-unit components in his car, breaching the limit of four for the season.

He's currently watching the rest of third practice from the garage after his earlier off into the gravel at the Vale chicane.

Marc Priestley
Former F1 mechanic on BBC Radio 5 Sports Extra

It's a long lap here, it's vey open, very flat and it's wet in certain parts.

It's quite a difficult thing to balance over the course of a lap and in particularly from an engineering perspective and making decisions about tyres.

Or maybe George Russell wants to carry over his Austrian good luck to home soil? The Briton has jumped above his Mercedes team-mate Lewis Hamilton by 0.035 seconds to lead the field with 26 minutes to go.

Andrew Benson
BBC F1 correspondent at Silverstone

Lewis Hamilton is looking very comfortable in these wet conditions, he's swapping the fastest time with Charles Leclerc in the Ferrari at the moment.

Every time he does a lap he's basically going to the top of the timesheets at the moment.

Image source, Getty Images

Forget Lando Norris versus Max Verstappen. That's last week's new. The battle at slippy Silverstone is between future team-mates Charles Leclerc and Lewis Hamilton.

The two drivers are swapping places at the top of the timesheets, with Mercedes' Hamilton the quickest of the pair with a new time of 1:38.065.

Meanwhile, Carlos Sainz receives an unwelcome call from his engineer at Luffield, so the Spaniard firmly tells his team not to contact him in the middle of a corner.

Sam Bird
Formula E driver on BBC Radio 5 Sports Extra

It's not so much about lap time where things stand at the moment, it's more about learning where the grip is, how the circuit is changing as the conditions are evolving.

1. Lewis Hamilton (Mercedes) - 1:38.511

2. Charles Leclerc (Ferrari) +0.179

3. Max Verstappen (Red Bull) +0.301

4. Lando Norris (McLaren) +0.607

4. Carlos Sainz (Ferrari) +0.918

Sam Bird
Formula E driver on BBC Radio 5 Sports Extra

We've just seen Lewis Hamilton on a cool lap finding wetter parts of the circuit to cool those intermediate tyres down.

This track is improving really quickly, still nowhere near slicks but the improvements are happening rapidly.

Those intermediates are warming up slightly now, along with the drying circuit, giving drivers slightly more grip than at the start of the session. George Russell moves to second on the timesheets but two becomes five as the Briton is pushed down the order by Sergio Perez, Max Verstappen, Charles Leclerc and his team-mate Lewis Hamilton.

Sam Bird
Formula E driver on BBC Radio 5 Sports Extra

These lap times are being lowered and lowered throughout this session.

It's a double-edged sword, at the beginning of this session you want to generate temperature in the tyres, so you've got to try and push from the offset.

It's not like a soft tyre in the dry where you have to tip-toe round. On these tyres you have to put the energy into the tyre to get the heat, but in order to do that you have to go through a little bit of pain on those first couple of laps.

Once you've got the heat you are going to feel the grip coming quite quickly and you are going to be able to perform at a much better level.

Pierre Gasly is the lonely driver back in the pits as every other car gets some valuable running in the slippery conditions. Charles Leclerc beat Lewis Hamilton's time to go top but the Ferrari man, after a few slips and slides, now finds himself in third spot behind Max Verstappen and...

Lewis Hamilton. A 1:39.546 for the seven-time world champion.

Marc Priestley
Former F1 mechanic on BBC Radio 5 Sports Extra

The intermediate tyres are very good in these conditions but the moment you start to get a dry line they are destroyed so quickly.

Lewis Hamilton, an eight-time winner of the British Grand Prix and a master in the wet weather, is top of the board with a 1:41.905 followed by the Red Bull of Max Verstapen.

"The track is definitely drying a bit now."