Ahead of today's opening session, the air temperature is 20 degrees C, while the track temperature is 29 degrees. It is bright and sunny. However, the big talking point is the tropical storm that is heading this way and is due to hit on Sunday.

Tyre options this weekend are medium (prime) and supersoft (option), while, unlike 2012, this year there are two DRS zones. The detection point of the first is 70m after Turn 2, with activation 360m after Turn 2. The second detection point is 60m before Turn 16 with activation 95m after Turn 18.

A couple of reserve drivers are on duty today, James Calado replacing Paul di Resta at Force India and Rodolfo Gonzalez is in Jules Bianchi's car. The Frenchman having been confirmed for another season with the Russian team only yesterday.

The lights go green and Gonzalez leads the way, shortly after he is joined by Maldonado, Chilton, Raikkonen, Bottas, Ricciardo and Calado.

The pit exit has been re-aligned and now runs through the middle of the run-off area at Turn 1, as the cars emerge it is noticeable that it is very bumpy.

Within five minutes all but Button and Vettel have made an appearance, and then, in unison, they head down the pitlane.

A number of teams are testing new bits for 2014, Mercedes running its passive DRS, while Ferrari has new bargeboards and McLaren a 2014 front wing.

While a few drivers complete two installation laps most complete just one, the track very green due to its lack of use. Fourteen minutes into the session Gonzalez is the first driver to come out for a second run.

The Venezuelan posts a 1:52.294, subsequently improving to 49.169 despite a couple of excursions.

As the Marussia driver posts 46.810, Vettel heads down the pitlane, surprisingly early for the world champion. The Red Bull is sporting a mighty array of sensors and whatnots.

Unsurprisingly, Gonzalez has pushed his luck just one too often and loses his nose after missing the apex and spinning at T13.

Around thirty-five minutes into the session, we finally get some action, Perez, Hulkenberg and Button taking to the track, a track that still, despite the promise, still appears to be in the midst of a building site. A building site on which work has come to a halt.

Perez posts 44.258 and Button 45.506 as more drivers get to work. Moments later Calado splits them with a 44.325.

Perez ups the ante with a 41.960, as Bottas goes second (42.637), ahead of Calado, Button, Maldonado, Van der Garde and Pic. Calado spins at T12 but is able to continue.

Approaching half-time, it's busy, Perez still quickest, ahead of Maldonado, Bottas, Calado, Ricciardo, Gutierrez, Vergne, Van der Garde, Button and Pi. Moments later Hamilton goes second (41.982) and Raikkonen third.