The Brazilian Grand Prix weekend got off to a wet start in both free practice sessions today, with no times set on the slick tyres and all the running taking place on the Cinturato Green intermediate and Cinturato Blue full wet. The P Zero Orange hard tyres and P Zero White medium tyres have been nominated for the race, but only the hard tyre was used briefly in FP1 by Red Bull driver Sebastian Vettel. The German's slick run was just for data gathering and he did not set a time with them.

The teams also had the new 2014 Pirelli development tyres available, but the weather conditions meant that they did not get the chance to drive on them. Again, only Vettel went out to do one lap on the prototype tyres. However, with more rain expected for the rest of the weekend, all the wet weather practice today was extremely useful.

The fastest time of the day was set by Mercedes driver Nico Rosberg early in FP1 on the Cinturato Green intermediate: 1:24.781s. Rosberg was quickest for most of FP2 as well, having set a benchmark time on the Cinturato Blue, before being usurped by Vettel on an intermediate tyre run. However, Rosberg managed to take fastest time back right at the end of FP2 with his own final run on intermediate tyres, thanks to a lap in 1:27.306s.

The rain eased off slightly at the end of FP2, with Sauber's Esteban Gutierrez the only driver not to switch to the intermediate by the end of the session. Most of the drivers used just one set of intermediates and wets throughout the day, even though the regulations allow for an extra set of intermediates if the Friday sessions are wet.

Paul Hembery: "It was a tricky start to the weekend here at Interlagos, but the conditions we saw are likely to continue for the rest of the weekend, so it was useful for the teams to establish a wet set-up and assess the performance of the wet and intermediate tyres with different fuel loads. It was a pity that the drivers didn't get the chance to try the development tyres as this was an important opportunity: on the other hand, the 2014 tyres are obviously designed for a completely different type of car to what we see competing for the final time this weekend, so there was only a limited amount to learn anyway. In the end the situation was just a bit unlucky, as on the two previous occasions that we brought development tyres to Brazil in 2011 and 2012, conditions remained dry on a Friday. You can't control the weather though, which has always been part of the challenge of Formula One. There is of course only limited data you can get from wet running and the risk of damaging the car is higher than in dry conditions, so teams tend to restrict running despite the fact that wear and degradation on both the intermediate and wet is low, as long as it continues to rain and the compound doesn't overheat. The intermediate tyre in particular has shown itself to be very adaptable yet durable over a wide range of conditions. It's hard to predict a strategy under these circumstances, as in the end it's the most quick-thinking and flexible tactics that tend to win in the rain – and of course there's always an element of luck as well."

Check out our Friday gallery, here.