Ahead of today's qualifying session the air temperature is 25 degrees C, while the track temperature is 47 degrees. It remains bright and sunny and warmer than at any previous point this weekend.

Following his crash this morning, Esteban Gutierrez will sit out this afternoon's session as such was the damage to the front of the car - not the rear as one might suspect - the team is changing his chassis and will rebuild it overnight.

Williams Felipe Massa was the fly in the Mercedes ointment this morning, the Brazilian splitting the pair with a lap that confirmed the Grove outfit's strong pace here.

Surprisingly, Lewis Hamilton and Nico Rosberg were two of several drivers who failed to improve on their prime tyre time once they made the switch to the options.

Consequently, much will depend on whether Mercedes can get its option tyres working this afternoon, if not the German team could be under serious pressure from Williams and possibly even Ferrari.

Certainly, in FP2 yesterday, the Williams duo looked very strong on their longer runs, as did the Ferrari pair, and whilst we don't quite see the Mercedes steamroller being derailed here we could see both teams take some serious points on to Austria.

Whilst Sebastian Vettel had issues, teammate Daniel Ricciardo was able to post the fifth fastest time, though the combination of fast straights and slow corners do not best suit the Red Bull.

Despite ongoing reliability issues, both Toro Rossos were strong this morning whilst, thus far, the Force Indias have failed to live up to expectations. McLaren and Lotus are also struggling.

The lights go green but it is almost three minutes before a car (Ericsson) heads down the pitlane. He is followed by the Williams duo, Hulkenberg, Grosjean, Perez and Maldonado.

Overtaking Ericsson on the out lap, Bottas begins the first hot lap of the afternoon.

The Finn gets proceedings underway with an 18.270. We should see that pared down by a further three seconds or more within the hour.

Massa leapfrogs his teammate with a 17.728 as Perez goes third ahead of Grosjean and Hulkenberg.

As expected, on his second hot lap Bottas is going quicker, retaking the top spot with a 17.696.

An early riser, Rosberg goes quickest in the first two sectors, crossing the line at 16.690 to go quickest as Magnussen momentarily goes second before being beated by Bottas.

Button voices his unease as smoke emanating from his left-front brake.

A 16.438 sees Hamilton go quickest as Button goes sixth ahead of Alonso.

With 9:15 on the clock the Red Bull duo leave the pits as Vergne improves to fifth with a 17.552.

Sutil is one of several drivers to have already switched to the option rubber, as Raikkonen has a worrying moment in the final chicane. Elsewhere, Rosberg is told that his team cannot hear his radio messages.

Probably just as well as Hamilton bangs in a 15.750 to go quickest by 0.721s.