FP1 - Rosberg leads the Red Bulls in rain-hit Austin

A damp Circuit of The Americas threw up some tricky conditions for Friday’s opening practice in the United States. With the drivers setting their best times on intermediate tyres, Mercedes’ Nico Rosberg led the way from Red Bull’s Daniil Kvyat and Daniel Ricciardo.

The way things are going, Friday’s sessions are likely to experience the best weather as worse is predicted tomorrow. And as anticipated, it began raining well before practice and the track was wet throughout, though dry enough for intermediates.

As the first man to start pushing and recording time laps, Sauber’s Marcus Ericsson reported that there was no real standing water, while Lewis Hamilton subsequently said the grip level actually wasn’t bad.

Once the Swede had opened things up, working down from an initial 2m 01.702s to 2m 00.996s, chased by team mate Raffaele Marciello in Felipe Nasr’s car on 2m 01.855s, Rosberg went out and reset the ante to 1m 55.102s. Hamilton didn’t record a time until the first half hour was done, then went second on 1m 55.693s before being immediately supplanted by Ricciardo on 1m 55.592s. In turn the Australian was deposed by team mate Kvyat, on 1m 55.224s.

Unobtrusively, Rosberg then banged in a 1m 53.989s lap which remained fastest as everyone started switching to race work.

Carlos Sainz showed he’s well and truly over his Sochi shunt with the fourth-fastest time for Toro Rosso on 1m 55.667s, leaving Hamilton - who completed just four laps - fifth for Mercedes ahead of Sebastian Vettel and Kimi Raikkonen in their Ferraris, which sandwiched Max Verstappen’s Toro Rosso. The German lapped in 1m 55.710s, the Dutchman 1m 55.969s and the Finn 1m 56.326s.

Fernando Alonso - running Honda’s updated power unit, unlike team mate Jenson Button - completed the top 10 with 1m 56.839s ahead of Williams’ Valtteri Bottas on 1m 56.866s.

Local hero Alexander Rossi outpaced Will Stevens at Marussia, while Pastor Maldonado didn’t record a time as his Lotus kept selecting neutral right from the outset.

More rain is expected for second practice this afternoon.