Sunday 13 May at 06:35 : May 13 (GMM) F1's season of confusion looks set to continue, with an uncertain weather forecast only adding to the uncertainty ahead of the Spanish grand prix.

The bizarre 2012 contest stepped into yet another gear on Saturday, with events unfolding to put the previously-derided pay driver Pastor Maldonado on pole, alongside the crisis-ridden Ferrari's Fernando Alonso.

And the Pirelli tyre predicament, worsened on the challenging Circuit de Catalunya layout and under hot Spanish skies, will continue to confound teams on Sunday, with temperatures set to drop and rain clouds predicted to gather.

"I am telling you now, honestly," said Red Bull's Mark Webber. "We don't have even the slightest idea who will benefit when it gets colder."

The German magazine Auto Motor und Sport laid out the fascinating if bewildering situation as of Saturday in Spain: "Sebastian Vettel doesn't know why his car suddenly lost grip in qualifying.

"Jenson Button has no idea why he couldn't generate any tyre temperature on the 40 degrees track. Williams don't know why Pastor Maldonado clocked the second fastest lap.

"Mercedes' engineers had to admit they still don't understand the Pirelli rubber."

Acting team principal Bob Bell smiled tortuously: "If we did understand, we'd be on pole. But even Pirelli don't know all the answers."

Writing in O Estado de S.Paulo newspaper, Livio Oricchio estimated there are up to 12 candidates for victory.

"A grid of madness!" said former F1 driver Patrick Tambay on France's RMC Sport. "And it's not over yet."

So, is Michael Schumacher - having sat out Q3 in order to save tyres for the race - now even more critical of Pirelli?

"I'll leave it with what has already been said," he insisted late on Saturday.