Despite the bright sunshine and searing heat, yesterday evening a number of teams were claiming that, according to their sources, today's weather would be entirely different.

Lo and behold, at around 5am, Daisy - one of the Pitpass cats, should you need to ask - who has been flaked out in the garden for the last few days, leapt on to the bed soaking wet. The rain had arrived.

Consequently, yesterday's set-up work was in vain, or was it, because whilst we are in for more of the wet stuff today nobody has a clue what tomorrow might bring.

However, at least that will mean a calming down on the strong winds that were battering the circuit yesterday. With grip already difficult, the strong gusts made it even harder to remain on the black stuff.

And then there was the reliability, or lack of it.

Be it Susie Wolff only completing one flying lap before succumbing to a technical issue or Lewis Hamilton suffering an engine problem shortly after posting the best time of the day, at some stage or another almost everyone was experience some sort of 'issue'.

Then there was Felipe Massa's crash in FP1 and Jean-Eric Vergne's mysterious problem with his left-front wheel which wanted to explore the English countryside.

Clearly, once again, the Mercedes duo rule, however, the Red Bulls also look very strong. Indeed, were they fitted with Mercedes power units we wouldn't see them for dust such is their aero advantage.

McLaren is also looking good, Jenson Button no doubt buoyed by the strong support for his 'Pink for Papa' campaign rather than Ron Dennis' gee-up earlier in the week.

Air temperature is 1616 degrees C, while the track temperature is 22 degrees. It is damp. Though it is no longer raining there was lots of it overnight and earlier this morning, and looking at the sky there is more to come. Consequently, it comes as no surprise that the session is declared wet.

The lights go green but there is no immediate rush to get to work. Eventually, Sutil heads down the pitlane followed by Maldonado and Button.

As more drivers head down the pitlane, mechanics are still working on Massa's car in the Williams garage.

While most drivers head back to the pits after a sole exploratory lap, Button, on Inters, stays out, claiming that there are some dry patches.

Within the first five minutes all but Hamilton have been out, the Mercedes driver having had no long runs yesterday. Eventually, he too decides to test the conditions.

Some drivers on full wets and others on Inters, as Bottas claims conditions are much better than he expected.

As Hamilton heads back to the pits and continues down the pitlane to perform a practice start, the sky is getting worryingly dark.

In the Marussia garage, Chilton is out of his car as his team reveals the need for a gearbox change, which means a five place grid penalty.

Ericsson, who was the cause of an extended yellow flag period yesterday when he 'beached' his car at Becketts, is the first driver to complete a flying lap, the Caterham driver stopping the clock at 1:57.091. Moments later teammate Kobayashi posts 59.947.

"More rain coming," warns Hamilton as Kvyat posts 56.404.

Replay shows a massive slide and wobble for the Russian in the final corner, the Toro Rosso driver doing well to keep it all under control. Indeed, watching from the McLaren garage, Button is clearly impressed.

Rosberg is back on track having switched from full wets to Inters.

The German goes quickest in S1 as Vergne goes quickest overall (55.232). He maintains his pace his pace in S2, as Kvyat goes quickest (54.657). The Mercedes driver then dives into the pits.