Spa in 1998 is proving popular in the category of best wet race.

You can refresh your memory by watching highlights here, if you're starved of race action (UK users only).

Get involved in the chat by using #bbcf1 on Twitter.

Image source, AP

The home straight resembles a steadily flowing stream at the moment. There is lots of movement in the car park at the Circuit of the Americas - I can't quite tell if it's people giving up and heading for home. It's probably a sensible idea.

Andrew Benson
Chief F1 writer

"There are reports that F1 boss Bernie Ecclestone and FIA president Jean Todt are planning to introduce a cheaper engine to run alongside the current turbo hybrid V6s.

"They are looking at a 2.2-litre twin turbo and an equivalence formula. It is no coincidence that it's the engine that is run in IndyCars at the moment - one of which is built by British company Ilmor.

"It’s highly likely to be a ploy to get the F1 manufacturers to put a limit on the cost of customer engines, which they have so far refused to do. Because the risk they face if the 2.2-litre engine goes ahead is that Ecclestone would ensure it was more powerful than the works engines by allowing it to run more boost or revs or both.”

A 19:30 BST start is looking optimistic, if that image is anything to go by.

We're asking for your craziest wet-weather grands prix - and your own scary drives in the weather.

Scratch that - qualifying is now set to start at 19:30 BST. 

Honda confirming what we were hearing - start time pushed back to 19:15 BST.

As we await a slightly delayed qualifying session, why not tell us about your most memorable rain-affected grand prix?

Also, what are the craziest conditions you've ever faced in the car?

Get involved using #bbcf1 on Twitter.

In case you weren't around, here are the times from that final practice session. Lewis Hamilton was almost a second quicker than nearest rival Sebastian Vettel, who will endure a 10-place grid penalty for exceeding the permitted number of engine changes.

You can read more about the session here, in Andrew Benson's report.

It's also been a weekend for social media milestones for Hamilton, who has notched up 3,000,000 Twitter followers.

Anyone remember Mario Paint for the SNES? It looks like Hamilton pulled this terrific picture together using that.

So far the signs are good that this could be a weekend to remember for Lewis Hamilton. He was by far the best in the wet conditions of final practice.

Here is how he can become the first Briton to win back-to-back titles and only the second, after Jackie Stewart, to win three.

Our chief F1 writer Andrew Benson is hearing there could be a 15-minute delay to the start time. 

There are still 40 minutes to go until qualifying, but it's not looking good.

The upshot is that numerous fans have been kicking their heels until they've been able to enter the circuit...

One of the more curious aspects of today's earlier practice session, was that it was played out in front of empty stands. The Circuit of the Americas decided it was too unsafe to allow spectators into the venue. The FIA decided it was safe enough to drive metal machines around at immense speeds.

The fans are coming in now - will they get to see any moving cars?

I'm looking at pictures of the pit-lane. At least I think it's the pit-lane. It could be a water slide at a fancy Spanish hotel resort.

I keep expecting Kevin Costner to pop up and find out I'm actually watching Waterworld.

Here's an update from Autosport's Lawrence Barretto. It's teeming down in Austin - still no news.

Image source, Rex Features

Welcome back one and all. We're one hour away from the scheduled start time of qualifying at the US Grand Prix - and as things stand, qualifying is set to start on time.

Lewis Hamilton was quickest in final practice - by far the quickest. If qualifying doesn't happen, it could be moved to Sunday morning. Otherwise, the times from FP3 will be used to decide the grid.

So, will we have any action in wet and wild Texas?

It's time to take a break and dry off.

We, like the teams, are just going to go ahead and assume that qualifying will happen at 19:00 BST. So you can join us from 18:00 BST for all the build up.

In the mean time, take a look at Andrew Benson's assessment of that thoroughly enjoyable session.

Image source, EPA

Lewis Hamilton is obviously the main man after that session - Sebastian Vettel was 0.863secs behind the Mercedes driver. After that the intervals are just tenths of a second - nobody could touch the world champion.

Vettel will be delighted if that proves to be the grid placing - his 10-place penalty means he'll only be 11th.

But Nico Hulkenberg deserves a special mention. The Hulk was consistent throughout to come in P3, more than two seconds quicker than his Force India team-mate Sergio Perez.