Hello and welcome to coverage of qualifying for the Belgian Grand Prix. It has started absolutely bucketing it down here so a wet session looks likely.

Hall an your to qualifying: don't know if it will be totally dry.. pic.twitter.com/RYyZS0PXX5

— Pirelli Motorsport (@pirellisport) August 23, 2014

The thing is, knowing Spa, it wouldn't be a huge surprise if the session turned out to be completely dry.....

As we saw in FP3, the rain seemingly opens the field up a little bit. It's perfect for the likes of Ferrari and Red Bull, who otherwise may have been at the mercy of Mercedes and Williams in a fully dry session. That said, Alonso and even, to a lesser extent, Raikkonen, looked good this morning.

No word yet on whether qualifying will be delayed with this downpour. At this rate the track is going to be very, very wet.

I tell you who is licking their chops right now - @CaterhamF1 and @Marussia_F1Team, who both reached Q2 here in the wet in 2010 and 2013

— Sean Kelly (@virtualstatman) August 23, 2014

Caterham new-boy Andre Lotterer was called a bit of a wet-weather master by the team in its announcement he would be replacing Kamui Kobayashi this weekend.

Says a lot about Spa that fans will come here rain or shine in their droves.

It's quite moist. pic.twitter.com/sN4W5d9Dpv

— Sniff Petrol (@sniffpetrol) August 23, 2014

Fifteen minutes until qualifying and Charlie Whiting is doing a lap of the circuit in the safety car. The rain has stopped, though, so should dry up pretty quickly.

Force India and McLaren may also surprise in wet. Past form indicates that Williams, low on drag but also on mechanical grip may struggle.

— Steve Slater (@steveslaterF1) August 23, 2014

And like that, the sun is out in Spa. What a place.

I'd imagine its intermediates for Q1. Unless of course, it decides to rain again.

Previous pole-setters in Belgium among the current field: Hamilton (2), Vettel, Raikkonen and Button (1).

Five minutes left until the start of this session. Genuinely tricky to predict anything this afternoon. I'm going to put my neck on the line and say a non-Mercedes pole.... but won't get more specific than that just yet.

Temperature currently 9 degrees Celsius, track temperature 21 degrees. There is rain in the distance. The risk of rain currently around 70%, there's quite a bit of wind around too.

Both Marussias are waiting at the end of the pit lane, both with the green-striped intermediates on their cars.

The light goes green and two Marussias head out, followed by the Caterhams, followed by the Toro Rossos. Everyone out on intermediate tyres.

Visibility is so poor out there when you see the onboard shots.

A few drivers going for the full wets, including Bottas, Sutil and Massa.

The Ferraris both head out on the blue-striped tyre, while Hamilton and Rosberg come out on the intermediate. To me it lookslike intermediate, there's been about 15/20 minutes for this track to dry.

Perez told there may be some rain towards the end of Q1. Key to get some banker laps in now for these drivers, who can forget Bianchi knocking Raikkonen out of Q1 in Hungary before the summer break.

Only Hulkenberg sat in the garage. Everyone else out on track for an early lap.

Kvyat having an almighty wobble through Eau Rouge and then runs wide on the run out of Bruxelles. Treacherous conditions out there currently.

Hulkenberg joins the circuit so now everyone is out on track.

Bianchi sets the initial benchmark, a 2:16.474. Chilton goes one tenth slower.

Kvyat goes 2:13.697 to jump into P1, before Bottas shaves nearly three seconds off that time on the wet tyre to take the lead of the session. Maldonado and Vergne both slot in behind him.

Massa runs across the chicane at Les Combes. Lotterer ran wide at the Bus Stop.

Hamilton has a big lock up and goes wide at the Bus Stop chicane but still goes fastest, setting a 2:09.492. Remarkable.

Hamilton says "please don't speak to me during my lap, Bonno" to race engineer Peter Bonnington.

Ricciardo 1.150s behind Hamilton currently.

Still no times for Lotterer and Hulkenberg.

And Hulkenberg jumps into fifth with his first time. Alonso goes fourth, 1.7s off Hamilton's benchmark.

Despite what it looked like earlier, intermediate appears to be faster and Rosberg slots in two tenths behind his team-mate. Ferrari have put the intermediates on Raikkonen and are about to do the same with Alonso.

Lotterer runs wide again, this time at Les Combes.

Looks like Lotterer just held up Grosjean on his way into the Bus Stop chicane, too.

Currently Raikkonen the biggest name in the drop zone.

Gutierrez has stopped out on the circuit and his qualifying session is over.

The marshals quickly remove his stricken Sauber from the race track and roll him across the run-off area. Not an ideal start to qualifying for Sauber. He's currently 15th but he will certainly drop down into the bottom six before the end of the session.

Raikkonen, now on the intermediates, is on a timed lap. He wobbles and lifts through Eau Rouge.

Every car out on track is on intermediate tyres. Vergne, Perez and Chilton in the pits.

Contrasting fortunes for Marussia. Bianchi 12th, Chilton down in the drop zone, 19th.

Raikkonen slipping and sliding around on this lap but he does his fastest second sector. This should be enough to take him clear of the drop zone.

Indeed, Raikkonen improves to fifth, 3.044s off Hamilton.

Bottas has just done a fastest first sector, he's now on inters.

Maldonado in dangerous territory in 15th but team-mate Grosjean jumps up to seventh with a 2:10.998. Kvyat leaps clear of the drop zone into eighth. Perez now a man in trouble but he's on a timed lap currently.

Lotterer needs to make five seconds to make the 107% qualifying time. His current best a 2:19.870, which was due to a Bus Stop chicane off during his flying lap.

Hamilton lowers his benchmark to 2:07.280.

Bianchi now improves to tenth.. Superb effort from the Marussia man. Chilton improves to 16th with a 2:12.566. It looks like the rain is starting to fall, too.

Chilton briefly out of the drop zone but is knocked back down by Sutil. Maldonado spins at the chicane and forces Vettel to abort his lap. He'll have one more lap to get free of the drop zone.

Perez improves to 11th. Hulkenberg can't improve on his time and is in really dangerous territory - he crosses with 20 seconds to spare so has one more shot to improve on his time.

Lotterer, meanwhile, is set to out-qualify Ericsson after shaving seven tenths off his team-mate's time.

Chequered flag - more times to come though, and Rosberg pips Hamilton into P1.

Maldonado is flying and could well do enough to drop Hulkenberg out of the session... though the German is also on a good lap.

He does, Maldonado goes 16th and just knocks Hulkenberg down into the drop zone. Sutil then jumps into 15th to push Maldonado back into the drop zone.

Hulkenberg does not improve, he stays 18th! He lost some two-and-a-half seconds in the middle sector. A little bit of a disaster for Hulkenberg as Perez makes it through Q1.

Lotterer outqualifies Ericsson by a full second for Caterham, though both finished 21st and 22nd.

Hulkenberg tells Force India his "brakes are just getting colder and colder and colder" and that he'd lost confidence braking as a result. He will start 18th.

In the drop zone, then. Maldonado, Hulkenberg, Chilton, Gutierrez, Lotterer and Ericsson. Gutierrez unlucky with his Sauber coming to a halt.

Super job by Bianchi to get his Marussia into the second qualifying session.

In that session, Mercedes looked pretty untouchable.

It's started raining again ahead of Q2.

BIA makes Q2 for 2nd year at Spa. #F1

— Maurice Hamilton (@MauriceHamilton) August 23, 2014

Good effort from Vergne as well, going fifth in that session. This the first race in his bid to find a home at another F1 team after being binned by Toro Rosso.

Bianchi proving with every race he's a star of the future. Ferrari no doubt taking notice in their young prodigy. Also hardly relieves the pressure on Chilton after the events of the last two days....

It's raining very heavily now.

The session is underway and Button is the first man out on track. Everyone opting for intermediates at this stage. These times could be the fastest of the session if the rain gets worse so some vital laps ahead.

It may well be dry at the end of the session but its a huge gamble to assume. Everyone out on track now and all on the green stripe.

Both Ferrari drivers have opted for a higher-downforce front wing, understandable given the conditions.

Grosjean sets the first benchmark, a 2:13.974, three seconds slower than his fastest time in Q1.

Times starting to tumble now as Button and then Bottas goes top, the latter posting a 2:08.470.

Hamilton has an off through Les Combes and navigates his way through the run-off area.

Alonso now goes top with a 2:08.470.

Rosberg now goes P1, three tenths quicker than Alonso. Hamilton starting a new lap, he's currently in the drop zone.

Rosberg ran wide at Rivage and still managed to go top of the session.

Hamilton goes purple in both the first two sectors of his latest lap.

Hamilton frighteningly quick through the middle sector. Hamilton jumps to P1, lowering the time to 2:08.108.

Raikkonen improves to P5. Ricciardo can only manage seventh with his latest lap, two seconds down on Hamilton.

Six minutes remaining. Kvyat, Perez, Sutil, Grosjean, Bianchi and Vergne in the drop zone.

The rain definitely getting heavier as he runs wide at Rivage again, he had just posted the fastest first sector in S1.

Button asks if he has time to come into the pits to change his wet gloves.

Rosberg can't jump Hamilton, he's four tenths off in second place.

Ricciardo now back in the pits. Raikkonen and Alonso have both taken on fresh intermediates.

Hamilton sets another fastest first sector.

Vergne finally out for his first timed lap and he has three minutes to improve on 12th and get himself into the final session.

Two minutes left in this session.

Rosberg now goes fastest through the first sector. Kvyat also on a very neat lap and he jumps into eighth, 2.288s off Hamilton and knocks Vergne (who improved on his own lap) into the drop zone.

Hamilton extends his advantage further, setting a 2:06.609. Eight tenths clear of Rosberg.

Rosberg loses time in the final sector, can only cross one tenth behind Hamilton.

Button in the drop zone by just a tenth but Vettel in a very precarious position ahead.

Ricciardo stays eighth but improves his time by a couple of tenths, that should be him safe. Grosjean crosses in 13th.

Vergne can't improve on 12th either. Can Button knock Vettel out?

He can! He goes 2.663s off Hamilton but how can Vettel respond?

Vettel secures his place in Q3 with his own lap, jumping into seventh. Big lap from the world champion after a poor first two sectors.

Vettel secures his place in Q3 with his own lap, jumping into seventh. Big lap from the world champion after a poor first two sectors.

Perez goes 13th so he will also drop out of this session.

So there we have it - Button just safe. Kvyat, Vergne, Perez, Grosjean and Bianchi all drop out of the session.

Seeing a replay of a Kvyat spin on the exit of Les Combes. Possibly what cost him a place in Q3.

Got to admit, I was holding my breath there for Vettel (still a fangirl) #BelgianGP #F1

— alelbuth (@alelbuth) August 23, 2014

Hamilton looks in pretty imperious form around here but Rosberg has five poles from the last six races to his name.

A great replay of Alonso catching a slide in the middle of Eau Rouge. That must be terrifying.

Mercedes 0.727s clear of all other cars in Q2. Even in 1988 Mclaren were only 0.453s ahead of the rest at in qualifying at Spa

— Sean Kelly (@virtualstatman) August 23, 2014

I think he means 1.727s, just to make it even more impressive.

No doubts Mercedes is in its own little world in the current conditions. The rest fighting over scraps for third at the moment.

Vettel the first man to go to the end of the pit lane, waiting for the light to go green.

The clock starts ticking and Vettel leads out, followed by Hamilton and Rosberg.

Alonso also straight out on track.

Rosberg lapping incredibly closely to Hamilton as they make their way round on the out lap. Alonso runs across the run off area at Les Combes, a few drivers have been caught out there.

And Rosberg has dropped back a bit slightly to give himself some clear air. Hamilton runs very wide at La Source.

Blues skies appearing so the track is only going to get dryer from this point.

Rosberg quickest through S1.

Hamilton lost 1.6s in that little off through La Source, which is almost the entire gap that covered the guys behind Mercedes so possibly not much sense aborting the lap at this point.

Vettel goes P1 with a 2:08.141.

But Rosberg goes purple in all three sectors, a massive 2:05.698.

Alonso goes third, nearly three seconds off Rosberg.

Hamilton's time, by the way, a 2:11.947, so he did back off in that first lap.

Bottas now goes into fourth, still a huge 3.6s off Rosberg's current benchmark.

Ricciardo can only put himself fifth. Button goes sixth. Both of them four seconds down on Rosberg.

Hamilton has a poor entry to the final chicane and crosses six tenths down on Rosberg. There's a massive 2.4 seconds between Rosberg and Vettel. Incredible.

Everyone has a time on the board. Massa struggling down in 10th compared to Bottas.

Vettel and Rosberg take a new set of intermediates.

ROS 2.5s faster than VET. 2.5! #F1

— Maurice Hamilton (@MauriceHamilton) August 23, 2014

This is an incredible advantage for Mercedes. Staggeringly good. Just under four minutes left in the session now as we see some quick stops for Magnussen and Alonso for new rubber.

Hamilton gets some fresh intermediate rubber and he's going to get one shot at pole. Rosberg should have enough time for two runs. Rosberg the master at putting his team-mate on the back foot in these sessions.

Massa and Alonso going into Le Combes nearly wheel-to-wheel. Both on their out laps.

Incredibly, Hamilton has not been on the front row since Canada. He will be here but will it be first or second? Rosberg not improving on his own time so far.

The track will be getting quicker as well with the sun now glaring down on the track.

Vettel improves his time and is now just two seconds behind Rosberg. Hamilton slows through the final chicane to get a bit of a gap and he slips and slides through the La Source hairpin. Really big lap ahead for the 2008 world champion.

Hamilton goes purple through sector one... we could have an interesting finish on our hands though as Rosberg has done the same!

One tenth in it between Rosberg and Hamilton through that first sector. Alonso slides slightly wide through Eau Rouge.

Hamilton absolutely flying through Pouhon but he runs a little wide -- he's up on Rosberg's current time.

Ricciardo just holds it together through Blanchimont, he goes fourth.

Hamilton loses time in the final sector and is one tenth down on Rosberg - who will be pole as he improves again. Four in a row for Rosberg.

Alonso splits the Red Bulls in fourth.

Mercedes' first front row lock out since the Canadian Grand Prix.

Rosberg has matched Hamilton's achievement of taking four consecutive pole positions last year - and done it in the same four races, as well.

Raikkonen could only manage eighth in that session but given how recent sessions have gone for him he will be happy to have been in Q3. Something to build on tomorrow. Important result for Vettel and impressive given that he missed most of Friday with that power unit issue - great effort from the world champion.

The cars pull into parc ferme. We get a familiar pump of the first from Rosberg and he gives the cameras the thumbs up.

Not the first time this season Rosberg has found an extra gear at the crucial moment.

Hamilton not in the mood he was in post-Britain as he shakes hands with Rosberg. Great effort today from the German, his Saturday form at the moment is almost as good as his form on Sundays.

Thanks as ever for joining us for qualifying. It looks like it could be a battle between the two men in silver tomorrow - please do join us again on Sunday for the Belgian Grand Prix.