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Formula One Weather Forecast: Japanese Grand Prix 2010

Ian Fergusson | 17:17 UK time, Tuesday, 5 October 2010

Suzuka, 8 - 10 October 2010 (Round 16)

(This forecast will be regularly updated. This entry: Saturday 9 October, 21:05hrs BST)

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Nowcast / Forecast Updates:

Saturday, 2100BST: As per model expectations (and they've been excellent this weekend), the rain has now left the circuit by 0500 Local and I'm expecting a dry or largely dry scenario to now prevail for the rest of Sunday. Good news for qualifying, then! One or two light showers are still possible, but it's a low % point probability and the real hazard for drivers is straying off the asphalt and into very sodden run-off  / gravel trap areas. So, quali could still be a tricky affair! One wheel off the kerbs could spell disaster.

Saturday, 1150BST: So, the 'worst case scenario' alluded to in my forecast below - i.e., a potential for undriveable conditions during qualifying - unfortunately became reality. We'll see a slow and rather erratic improvement in conditions for the rest of this evening and tonight in Suzuka, but JMA weather advisories and warning currently remain in force, not least to cater for further heavy pulses of rain easing northwards along ripple or wave-like perturbations on the frontal zone. Areas of flooding, with landslip risk, are a real possibility in some parts of Mie Prefecture. The postponed qualifying on Sunday (10am local; 0200BST) will take place after the rain departs; current modelled estimates take it's back edge of away northwards from Mie by around 04-0600 local. The circuit will thus still be pretty tricky for qualifying - especially the sodden margins & run-offs - but steadily drying.  We'll then see hints of the cloud deck breaking with some brighter spells developing progressively towards midday. During the qualifying window, there's still a (small-ish) chance of a few light showers - these are catered for as a 30% chance of PPN by JMA's forecasters (and with good inter-model support). The race, meanwhile, remains as previously forecast: dry, with brighter or sunny spells; much warmer and with a low (10%) prospect of any further showers.


Forecast Summary:

(PPN = Precipitation)

Emphasis: Unsettled conditions developing PM & overnight Friday, bringing spells of heavy rain Saturday, especially PM, continuing into Sunday AM. Inclement weather will have cleared well ahead of race start.

Friday: Sunny spells; mostly dry but with a chance of a few showers later PM as cloud increases.  Rain arriving through the late afternoon and overnight, heavy at times. Chance of PPN 30%. Max 24C. Wind light, SSE.

Saturday: Overcast and breezy, with outbreaks of rain throughout the day, turning heavy at times and especially during the afternoon and evening. Up to 50mm accumulation plausible. Continuing wet & rather windy overnight. Chance of PPN 90%. Max 21C. Wind freshening / brisk SE.

Sunday: Further outbreaks of rain through a cloudy morning, easing by mid-morning. Dry and probably brighter by race start; i.e., a damp circuit then steadily drying(?). A few light showers still possible during early afternoon. Chance of PPN 80% AM; 20% PM. Max 25C. Wind moderating, predominantly NW. 


Synopsis & Forecast Evolution:

There's now broad inter-model consensus for a tropical low / wave-like depression to form off Taiwan during Thursday and move NNE towards Japan. The centre eventually tracks just offshore east of Honshu throughout the weekend and deepens, with an arm of the jetstream directly aloft - offering significant potency and fluidity in the eventual degree / extent of bad weather across Suzuka, especially throughout Saturday.

Currently, the most pessimistic solutions from major operational centres (e.g., Canadian CMC; UKMO, NOGAPS and to an extent, GFS) offer a very wetr propect for Qualifying. This is likely to prove the major point of weather-related interest / uncertainty in an already critical race weekend for the five championship protagonists.


Whilst Friday has a pretty decent chance of dry running for P1 and P2, the onset of inclement conditions appear later into the evening and become dominant during Saturday. With FP3 and qualifying in mind, this will be real concern for the teams.

As the low tracks north, it is likely to become very developmental across Okinawa during Saturday and with various wavelike / ripple perturbations running ahead (possibly forming a secondary low centre) into southern areas of Japan, offering a real potential for heavy showers, including across Mie Prefecture (and Suzuka, located therein).

All the models agree on some grim weather throughout Saturday and especially later in the day. As soil moisture deficit continues to shrink from later Friday onwards, substantial run-off and standing water could become a real issue around the circuit by Saturday.  Timing will be critical as the model continuity improves: i.e., will conditions possibly worsen ahead of qualifying, or after? It's more likely to be after... but impossible to call reliably until we see reality unfolding on radar. With 50+mm rainfall accumulation not out of the bounds of probability, there's obviously a possibility of undriveable (red-flagged) weather but this can be considered a fairly low risk. The worse conditions presently look set for the late afternoon and evening.

Either way, the low centre continues to look very threatening by 00GMT (0900hrs local) on Sunday morning but thankfully, it's impact on the actual race should then be steadily reducing.

In broadscale terms, the low centre is likely to be located just offshore from Mie Prefecture during the early morning and tracking NNE, if the currently fairly good inter-model agreement can be trusted.

The precipitation (and trailing cold front sitting off to the south) then ease off to the north quite quickly during Sunday morning, so the race itself will be dry or largely so. However, the earlier rain will have kept the circuit very sodden during the morning and I'd imagine the margins / run-off areas / section beneath 130R crossover will remain treacherous!.

One possible complication towards the early afternoon is any degree of wrap-around occlusion debris swinging back from the north towards Mie,  bringing a few light showers, especially with any sunny spells adding to daytime heating and instability. With this in mind, I've retained a 20% point probability of afternoon precipitation and I note the Japanese Meteorological Agency do likewise. However, it's very likely for this critical race to run entirely dry, without further weather interruption. Exactly what grid line-up we'll have by the end of Saturday might well have provided more than enough weather drama, anyway!


  • Comment number 1.

    Sounds like a very very difficult forecast to predict for this weekend. Hopefully we won't see undriveable conditions, but it sounds like even at this stage, that both Saturday and Sunday are very much on a knife edge in terms of when rain falls, how heavy, but also when the rain stops and how quickly the track dries. Certainly seems like the teams may have to gamble as to what sort of setup to go for in qualifying, given that they can't change it for the race. Obviously things should become a bit clearer as we get closer to the race weekend, but certainly looks like it's impossible at this stage to be even remotely certain of the forecast.

  • Comment number 2.

    Japan is one of those tracks where it is hard to drive in the dry. One mistake and you could be stuck in the gravel. So if it does rain we could see some gambles and brave moves.

  • Comment number 3.

    I am a non-native English speaker. Perhaps for native speakers it looks normal, but I think your writing style is great! Is that a fair comment?

  • Comment number 4.

    It really does look like a knife edge situation this weekend. Hopefully we won't see any weather related red flags, but Saturday at this stage does look pretty bad. It'll be interesting though with the timing as to how long the rain hangs around on Sunday, ie if it's all gone by dawn, or still the odd light shower here and there (race starting at 3pm Japanese time of course). I don't envy your task forecasting the weather for this weekend Ian, it looks like you could have your work cut out, but really do appreciate the very detailed updates you give us.

  • Comment number 5.

    Hi Stevvy (et al.), thanks for the comments. Re the race window - the continuity between the main operational centre models is good; i.e., clearing the rain away northwards ahead of race start by some margin. Thus, a shower or so aside, I'm expecting it to run in dry and increasingly bright / sunny conditions, albeit areas of the circuit asphalt might still be damp (e.g., beneath the switchover bridge) and more broadly the circuit margins / run-off areas etc.
    Equally, the continuity for Saturday's inclement conditions is looking strong and frankly it'll be about the regional areal / timing nuances of just how wet things become.
    Best, Ian

  • Comment number 6.

    Well, it seems like we should get away with 2 dry sessions on Friday, but sounds like Saturday is still basically certain to be wet. Just a case of how wet now. Sounds like very heavy rain Saturday night into Sunday morning though, but seems like once the rain clears, it'll become warm and sunny, probably quite early in the day.

  • Comment number 7.

    When was the last time in an f1 race that it rained from start to finish without stopping?

  • Comment number 8.

    China 09 I think, and before that........probably Japan 07

  • Comment number 9.

    Should be very interesting on setups this week. I was watching the Classic Japanese Grands Prix today and one of them was red-flagged after hail. I hope that doesn't happen for any of the sessions.

    My article: http://www.bbc.co.uk/dna/606/A75116720 gives a selection of different forecasts but I must say they are all relatively similar to this one.

    Just one question. This rain on Saturday night/Sunday morning. It's predicted to be a few inches of rain but what I want to know is how long it would take for an even surface to dry a track that has had 75mm of rain in around 12 hours. What variables decide how long it takes?

    Thanks Ian for all the updates. It's much appreciated.

  • Comment number 10.

    Hi James, I just spent 50 mins writing a detailed blog update... but a broadband disconnection then wrecked it!! So in quick summary: Your 606 entry suggests I'm forecasting a wet Sunday...not strictly so. Rain in the morning; yes, for sure - but crucially, dry ahead of race start and I expect it to be a good deal brighter and warmer by then, too.
    Saturday is the real problem for this weekend, forecast-wise and for that matter in terms of track action. We could see torrential downpours at some stage into Saturday PM, but I'm hopeful these will be post-quali. No-one wants to see undriveable conditions, of course. Re Sunday; the factors determining track condition are varied: how much rain has fallen (a lot, me thinks); evaporation rate courtesy of insolation, relative humidity; wind etc.... I would wager on wet areas of circuit margins and run-offs still by race start; probably ditto under the bridge cross-over beneath 130R and elsewhere too. So, probably dry 'from the sky' into the race but not a clear-cut dry circuit in the broad sense of venturing offline. One or two light showers are also still possible even by race start, but it's looking a good deal better compared to Saturday, by a huge margin!! Best, Ian

  • Comment number 11.

    That's really frustrating regarding losing your detailed blog entry after 50 minutes of writing it. Really do hope the worst of the rain comes after quali though, nobody wants it to be red flag conditions. I sort of get the impression that track conditions on Sunday, assuming we don't get any further light showers after the really heavy rain, will depend entirely on when the rain stops. If it stops at say 9am, with the amount of rain forecast, I can see the whole track being slightly damp, with wetter patches offline/under the bridge/run-off areas. Even in that respect, it's going to be uncertain as to the track conditions, as the timing of the end of the rain doesn't seem 100% certain yet. It does sound like we could end up dodging a bullet though on Saturday in terms of the REALLY heavy rain, as I suppose another issue is the build up of rain over a period of time, which can cause problems in itself.

  • Comment number 12.

    Just another quick thing as well, there's only going to be about 1 hour of on track action on Sunday before the start of the race, which will help dry the track slightly, but shouldn't make too much difference. Just wondering as well as to whether the combination of the heavy rain, as well as possible low cloud could create a problem with fog on Saturday morning. Just a thought, and may be a pointless 1 if there's no chance, it just seems possible to me for some reason (maybe I'm thinking of Fuji and the issues there with Mount Fuji, fog, etc).

  • Comment number 13.

    Well, it's currently raining apparently, and Saturday looks 100% certain to be wet (haven't said that in a while). I know you talk about red flag conditions being a low risk possibility, but my gut feeling says that we will see red flag conditions, mainly in quali, what with the build up of rain etc. Obviously I don't want red flag conditions, but I do expect them if I'm honest.

  • Comment number 14.

    Ian, do you think we're heading into potential cancellation conditions for tomorrow's Qualifying?

  • Comment number 15.

    Hi D_M_N; it's an issue seemingly raised also at Suzuka (according to my BBC colleagues there). The problem faced is fairly simple: The rain is now gathering just to the SW (see rainfall radar link, top of this blog) and with model continuity proving excellent, we can anticipate heavier rain to encroach progressively from now through Saturday, with no real let-up (other than the usual ebb-flow of somewhat drier interludes) between now and Sunday AM. If anything, a delay to later Saturday could, in my view, prove even worse. A delay to Sunday AM is clearly leaving things up against the wire for team race prep, but is not impossible I guess.
    Personally I think they'll go for it Saturday, at the alloted time. OK, it'll be a wet scenario but to what degree (in terms of rain rate each session; amount of standing water etc) is presently impossible to guess and I think it would require something truly exceptional to red flag the whole gig.
    FP3 will provide some important answers frankly... let's wait and see and keep eye on the radar!

  • Comment number 16.

    If only this was a European race I'd be looking at the radar in the hours before Qualifying - tomorrow I'll be getting up at 5am, I'll be a tad annoyed if there is no action. ;)

  • Comment number 17.

    I do get the impression that any red flags (be they for the weather or accidents) will only lead to heavier rain, as it does seem like the heavier stuff will fall once quali starts. As far as doing quali on Sunday morning is concerned, they managed fine there in 2004 (all Saturday action was cancelled on the Friday due to the expected arrival of Typhoon Ma-on which thankfully changed course at the last minute and missed the track), and they managed to get that on no problem (and that was in the days of pre qualifying and then qualifying itself), so I don't see that being an issue this year if it comes to that. Just hope we get all 3 quali sessions in. Though you may be interested by this tweet from Jonathan Legard:

    F1 first - saw sandbags around circuit at T1 and Degner when running Suzuka. Must be expecting a lot of rain...

  • Comment number 18.

    Hi Stevvy, yes I saw Jonathan's comment. I think it's worth stressing that I'm not anticipating some sort of exceptional rainfall event (!), just a threat of periodic bouts of heavy / torrential downpours coupled to more prolonged spells of moderate to heavy rain. So, in the broad sense, nothing worse than we've seen in many previous F1 events worldwide but it's the compound / cumulative effects of many hours of rain on this particular circuit that could make sections either too dangerous (waterlogged run-offs etc) or undriveable. We shall see. That's worst-case scenario. I'm hopeful they'll be able to navigate the circuit OK and whilst wet conditions look certain to prevail, fingers-crossed it's nothing too problematic for the organisers. Best, Ian

  • Comment number 19.

    Well I do hope for the same Ian, in terms of the drivers able to navigate the circuit ok, no red flags, etc. As you say though, it does seem to be the effect of so many hours rain that's going to be the biggest problem. Even if there was just a 3 hour period where it was bone dry it'd hopefully help to clear at least some of the water, but that doesn't sound like it's going to happen.

  • Comment number 20.

    After reading this blog, I think it won't rain during Quali, the showers could arrive before qualifing and rain again later in the evening or overnight.

  • Comment number 21.

    Theo, you're wrong, it will rain at some stage during quali even if it's just light rain, it will be a wet session. Unless it stops raining now and doesn't rain again, it'll be a wet session, and I can tell you right now that it'll carry on raining, and we will get a wet session. There's absolutely no doubt about it.

  • Comment number 22.

    OK stevvy1986,

    Perhaps you are correct but predicted rain does not always arrive on queue. as you said, it could be a wet session because of earlier rain.

  • Comment number 23.

    Does anyone know what happens if qualifying is wet but Sunday's race condition is dry and what would be the tyre choice/regulation for Sunday's front runners?

  • Comment number 24.

    theo 55, if qualy is wet and race starts dry, then the WHOLE field can choose either of the dry tyres at the start on sunday.

  • Comment number 25.

    Correct sato113, although they will still have to use both types of dry tyres unless they have to put inters/full wets on during the race/for the start.

  • Comment number 26.

    Not good, there's an advisory from the JMA for the area, the advisories (looking on their website) being for gales, storm surges, and thunderstorms.

  • Comment number 27.

    This tweet from 1 of the Autosport guys makes me worry big time for quali (hope you don't mind me mentioning it's 1 of their guys by the way, just passing on info):

    There is an extremely nasty storm cell 50 miles to the south of #suzuka #F1 circuit. Is currently bang on course to strike in the next 2 hrs

  • Comment number 28.

    Well, I don't think any of us are happy about the red flag conditions, but they obviously had no choice, the only safe way they could've been allowed on track would've been if they'd been given powerboats. Will have to wait and see what happens for quali in terms of the track and how dry it is, but even if it's dry, if you go off over the grass, you're going to bring up alot of water I'd imagine, as the run-off areas will be absolutely sodden. Seems pretty certain that the race will be dry though, which is good, and I have to say I think having the quali session on the Sunday morning only increases that chance, even if quali starts damp, purely because you'll have cars running on track clearing up any lingering wet/damp patches. Good job this didn't come tomorrow though, because as we saw, even the safety car was struggling at times, and to even have a race totally under the safety car wouldn't have worked, but anyway, at least it'll gradually improve.

  • Comment number 29.

    Well it did allow me to catch up with Emmerdale Omnibus on ITV2!

    Still hope we at least get some weather tomorrow morning. A bit disappointing to have completely dry weekend merely because it was too wet.

  • Comment number 30.

    This comment was removed because the moderators found it broke the house rules. Explain.


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