The day started off wet with a couple of drivers finally switching to slicks shortly before the lunch-break. However, further rain in the afternoon, including a thunderstorm, and reduced visibility that saw the medical helicopter grounded, meant that few drivers ventured out - much to the disappointment of the 15,000 fans present.

Alonso's programme for the day included development of new components and increasing the understanding of the behaviour of the tyres. Unfortunately, the conditions, with only a small window of dry time in the late morning, required a drastic revision of the programme. The afternoon was particularly limited, when the only work carried out was some practice starts.

"It's a shame about the rain," said Alonso, "which complicated the running of this first day of testing and a shame for the spectators who deserved to see more of a show.

"We had a pretty busy work programme, but we only managed to get through a part of it. Therefore, it's impossible to give a serious evaluation, especially as we did so little dry running.

"I can only say that, for me, it was a pleasure to be driving at this track again," he added, "the first and only other time was back in 2001, when I was testing for Minardi. It's a spectacular track and it would be nice to be able to race on it!"

Mark Webber was on duty for Red Bull, the Australian completing 24 laps on his way to posting a best time of 1:23.648.

The morning conditions led Red Bull to run a re-worked plan, which included some running on intermediate tyres. The Austrian outfit used those outings to test a number of aerodynamic and mechanical development parts, which had been brought to Italy for the test.

The brief lull in the wet weather later in the morning gave Webber a couple of dry tyre runs and the team maximised the opportunity before the heaviest rain of the day arrived.

"Obviously, the weather wasn't great today," said the Australian, "so we didn't get to do much running in the dry. Really, we only got one decent run on the slicks. Then it rained after lunch and with limited sets of wets available, you can't do that much. We're hoping for better over the next couple of days.

"It's an important test. We have a lot of information to gather and, while today didn't quite work out as expected, I'm optimistic that over the course of the next few days we'll get the information we need.