Saturday morning, and the weather in Cardiff is as gloomy and wet as a mole’s bathtub.

The atmosphere, however, is starting to sizzle.

With the hours falling away until kick-off, the talk among the thousands of soggy fans is all of omens.

The Gallic hordes, uncowed by the wintry rain, are in boisterous mood. Ask them how they think the match will go and they clobber you with a succession of stats that are hard to argue with.

Un: France have never lost to Wales at the Millennium Stadium. Deux: The last time they played here, they knocked white-hot favourites New Zealand out of the World Cup.

Trois: Wales have lost each of their last four Six Nations matches against France in Cardiff, and their three victories in the last nine championship meetings between the two (1999, 2001, 2005) have all come in Paris.

Aha, say the Welsh supporters loosening their throats and gullets for the long day ahead. This is the year for ending miserable streaks.

We hadn’t won at Twickenham for 20 years, or in Dublin for eight. Remember what happened there?

Remember what happened in 2000, retort the men in blue. We destroyed you 36-3 – a winning margin 13 points bigger than we need to steal the championship from you this time.

Not only that, but one of the men who did so much damage that day, Emile Ntamack, is in the French dressing-room again, as his country’s backs coach. And one of the men in red who got trampled all over, Neil Jenkins, is an integral part of Wales’s coaching team.

Who cares? say the Welsh. The French pack of today is nothing like the massive wrecking-ball it was that day. Show us a man in the current pack as darkly destructive as Abdel Benazzi or Fabien Pelous.

What about Thierry Dusautoir or Julien Bonnaire? comes the reply. Marc Lievremont’s experiments with fresh-faced youngsters are over. The beef is back.

Beef? laugh the locals. Ropey old mutton, more like. He gets rid of the old guard because they’re not up to it any more, and then panics at the first sniff of the Welsh front eight and brings some of them back to play in a combination they’re completely unused to.

Anyway, it's 30 years since we beat France in another Grand Slam decider in Cardiff. And it's 100 years since the first of our nine previous Grand Slams.

And so it goes on. Behind all the bluster and bravado lies palpable anxiety, pure and simple.

The Welsh fans don’t want their gloriously unexpected fairytale to end with the ugly ogre running off with the treasure. Grand Slam opportunities are as rare as the hairs on Shaun Edwards’ pate.

The French, meanwhile, are terrified of identity theft – that another northern hemisphere team beside them could tear apart stodgy rivals with a heady combination of forward strength and a showman’s flair through the backs.

Will Wales continue to start slowly? If they’re as sluggish out of the blocks as they were against England (16-6 down at half-time) or Ireland (hanging on 6-3 at the same point) the French could run away with it.

If France build a lead like England’s, whisper the nervy ones, Wales will have to start chasing the game. And with James Hook starting ahead of Stephen Jones at fly-half, they will have already taken the more attacking, running option at 10.

Equally, if France are as overwhelmed by Wales’s remarkable second-half fitness as everyone else this year, any lead they carry into the second period could be wiped out in minutes.

Wales have won every second-half in the tournament so far – by 20 points to three against England, 20-9 against Scotland, 34-0 v Italy and 13-3 v Ireland.

They’ve also stuck with the tactic of kicking the ball deep into play rather than into touch – which has worked beautifully so far, but could be suicidal against a France back three of Vincent Clerc (five tries in the first two, very open, games), the massive Julien Malzieu and side-stepping Anthony Floch.

So many scenarios, so few hours to go.

The roof is closed over the Millennium Stadium. The bars have opened their doors. It’s time for deep breaths all round.