Nico Rosberg has launched into action, jumping ahead of Mercedes team-mate Lewis Hamilton into fifth place.

We're shown a shot of Pastor Maldonado wrestling with his Lotus - the Venezuelan just about steadies the ship.

James Allen
BBC Radio 5 live F1 commentator

We have 40 minutes of FP3 remaining, the rain is worsening, but the times are improving. Felipe Massa's engineer has told him the next five minutes will be the best window to get a good time. 

Daniel Ricciardo is back out - he can only move up to 12th.

A terrific lap from Nico Hulkenberg sneaks him up to third - it could be perfectly timed with the rain worsening.

So now it's Sebastian Vettel (2:00.380) from team-mate Kimi Raikkonen. The Finns tells his team: "I have a lot of aquaplaning in the first sector."

Valtteri Bottas, Lewis Hamilton and Nico Hulkenberg make up the top five.

I wouldn't expect the cars to stay out much longer - the spray is everywhere.

Confidence is building on the track, but Sebastien Vettel, who has now set the quickest time, tells his Ferrari team: "The rain is getting heavier. Box now."

BBC Radio 5 Live

Don't forget, you can listen to live commentary by using the Live Coverage button on this page. I'd recommend it wholeheartedly.

Despite that little imperfection, Lewis Hamilton has the quickest time - 2:02.561.

He's followed by Valtteri Bottas, Sebastian Vettel, Fernando Alonso and Nico Hulkenberg.

There is a feeling that more rain is imminent - so these precious few minutes could end up dictating the qualifying positions, should things not improve.

Hamilton and Rosberg have both come a cropper. Hamilton aquaplanes and zig-zags off before recovering. And there's a spin for Rosberg, who may have damaged a wing in the gravel.

"You've got no front wing," say Mercedes over the radio.

There's plenty of experience out there now, with Lewis Hamilton and Nico Rosberg among the drivers on the track. 

Daniel Ricciardo has completed his lap - 2:12.758. Rosberg's leading time yesterday was 1:53.989.

"Lots of water, but not too bad," Daniil Kvyat tells his Red Bull team over the radio.

Image source, AFP

Friday saw a very sedate first practice in wet conditions end with Nico Rosberg top of the pile. In the couple of hours before second practice the Texas sky emptied every last bit of precipitation it had in it. And as a storm neared Austin, the sensible decision to call off proceedings was made.

And while there was little action, I would still recommend reading Andrew Benson's assessment of how the weather might affect the rest of the weekend.

Red Bull's Daniel Ricciardo is the lucky/unlucky soul to take on the water rapids first. Let's see how this goes...

Miracles of miracles... P3 has officially started.

Karin gets Brownie points for being a dedicated reader - yesterday's live text commentary descended into absolute farce. But we did get to discuss the highlights of James Marsden's acting career.