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Autumn blast on its way

Paul Hudson | 15:12 UK time, Friday, 21 September 2012

A deep area of low pressure looks set to dominate our weather late in the weekend and into next week as the official start of autumn (which is the 22nd September this year, defined as the day the sun crosses the equator into the southern hemisphere) coincides nicely with the first meteorological blast of the season.

The track of this low pressure is still open to question, and has been causing real problems for forecasters in the last few days.

It's down in part to ex-hurricane Nadine which is in the mid-Atlantic near the Azores.

Computer models invariably struggle to handle these storms because such systems are relatively small but intense, and as such can be difficult to model with any consistency.

What Nadine does in the next few hours will help determine where an associated area of low pressure will develop and track, drawing in some of Nadine's warm sub-tropical air, hence the uncertainty regarding the timing and location of potentially heavy rain and strong winds for the UK.

The chart below is the best estimate of its position at midday on Monday, based on the UK Met Office Global model.

The current best estimate for our area is for the heavy rain to hold off until late Sunday, with much of next week then very unsettled, at times windy, with showers or longer spells of rain.

On a more positive note, if timings remain the same, it does mean that much of this weekend across Yorkshire and Lincolnshire will be fine and sunny, albeit cold at night with a risk of rural frost.

Follow me on twitter @Hudsonweather


  • Comment number 1.

    Hi Paul. that's a pretty big call. NADINE has been on a holding pattern south of the Azores unable to make up it's mind for some days now.
    http://www.nhc.noaa.gov/refresh/graphics_at4+shtml/143657.shtml?5-daynl. The USNHS consensus forecast is for the remnants to be somewhere WNW of the Cape Verde Islands come Wednesday. Are you sure you've got the right week?

  • Comment number 2.

    I hope you are right about it being a nice weekend for my sins i'm in Skegness!
    #grumpyoldman58 correct me if I'm mistaken, but Paul isn't saying Nadine is coming our way, but is playing a part in where another area of low pressure heading for the UK will form and develop.

  • Comment number 3.

    Is it advisable to get some Braising Steak and Stew meat in then maybe some Lamb for a Hotpot or are we likely to be on salads again early October like last year

  • Comment number 4.

    "The track of this low pressure is still open to question, and has been causing real problems for forecasters in the last few days."
    24 hours ago, the web forecast for the NE said there was going to be heavy rain and strong winds today, but neither haver materialised.
    The strong winds forecasted for Monday appear to have been delayed until Tuesday.

  • Comment number 5.

    We have already had a touch of rural frost here a couple of nights ago. Only ground frost so far. Seems like a fairly chilly early autumn is setting in. Going by natural "signs" I am guessing this year as a whole will turn out to be the coolest for some time unless there is a dramatic change very soon.

    #4 - we had quite a bit of rain today.

  • Comment number 6.

    According to my data, the lowest max temp set in Sheffield this early in Sep was 10.0C in 1976. We must have been pretty close today. I reckon we made it to 10.0C in Stocksbridge, but Sheffield is usually half a degree higher.

    Either way it has probably been in amongst the top 10 coldest.

  • Comment number 7.

    This year has proven to be quite volatile, certainly in the UK with a poorer than usual growing season, which is the basic bottom line where weather is concerned. Three months to go and I am certainly thinking that 2012 will be a lot closer to 2011 than I originally thought, perhaps we are at solar max now.

    Thoughts on this winter, a lot of agencies are saying average to slightly warmer than average temperatures as their forecast at this stage. Maybe, maybe it could get a bit colder, if not this year then certainly for Jan, Feb.

    My original forecast of 0.28 for 2012, this may be a little low but still, I think, closer than the MO, perhaps an increase for this years prediction and a lowering of next years in my mind, QV AT 0.34 could hit the spot this year, but three months is a long time where weather is concerned.

  • Comment number 8.

    Herewith the latest, and possibly last, post-tropical NADINE Forecast discussion by NHS. Note particularly Para 3.


  • Comment number 9.

    Once again, the forecast for the NE has changed, with strong winds and heavy rain now forecast to start on Sunday night, instead of Tuesday.
    Monday, having been wet but without strong winds is now down for heavy rain all day and strong winds, peaking at about 07:00.
    All this proves is that 5 day local forecasts are pretty much a waste of time.

  • Comment number 10.

    #7. - ukpahonta wrote:
    "My original forecast of 0.28 for 2012, this may be a little low but still, I think, closer than the MO, perhaps an increase for this years prediction and a lowering of next years in my mind, QV AT 0.34 could hit the spot this year, but three months is a long time where weather is concerned."
    I think my forecast is looking on the low side now and I expect a final figure of around 0.42c.
    I do expect temperatures to decline on average, over the next 5 years, but getting the timing exactly correct is difficult.
    I certainly don't expect any new records, as forecast by the MO.

  • Comment number 11.

    #5. - jkiller56 wrote:
    "Seems like a fairly chilly early autumn is setting in. Going by natural "signs" I am guessing this year as a whole will turn out to be the coolest for some time unless there is a dramatic change very soon."
    I am not sure if you are referring to your local temperature as a whole, but the rolling 12 month CET figure is currently running at 10.4c, compared to the 1961-90 average (which may be a bit low), of 9.45c, so about 1c above normal.
    The year to date figure, according to the MO is 10.27c, against a 61-90 of 9.78c.
    The rolling 12 month CET reached 8.85c in December 2010, which was the lowest figure since March 1987, and this year looks like being cooler than last year, but warmer than 2008 and 2009.

  • Comment number 12.

    The first part of the first sentence should haver read;
    "I am not sure if you are referring to your local temperature or the U.K. as a whole"
    Why is there no retrospective edit facility on this blog????

  • Comment number 13.

    Briefly, from the 'Wet end to September raises autumn flooding concerns' thread, but probably also relevant to this one.

    101. 21st Sep 2012, ukpahonta wrote:

    "[ENSO] gives the process of the ocean absorbing energy from the Sun and then releasing it to the atmosphere. La Nina, and neutral conditions to a lesser extent, absorb energy into the ocean, El Nino releases energy into the atmosphere."

    That explains ENSO's role in distributing heat energy at the atmosphere/ocean interface. But it doesn't explain the steady rise in global temperatures observed throughout the 20th century, and especially in the past thirty years. Distributing heat is not the same thing as creating it.

    5. 21st Sep 2012, jkiller56 wrote:

    "Going by natural "signs" I am guessing this year as a whole will turn out to be the coolest for some time unless there is a dramatic change very soon."

    Not sure whether you're referring to local, regional or global temps here. But according to MO data year-to-date (Jan-Aug) in the UK 2012 is a little above average for the past 30 years, and spring 2012 (Mar-May) was in the top ten warmest on record (started 1910).

    So temperatures in the UK would actually have to *fall* dramatically relative to average throughout the rest of 2012 to be considered one of the coolest on record, or even to match those seen in 2010.

  • Comment number 14.

    newdr54 - it is apparent from your posts that you either briefly 'scanned' the Tisdale post or did not bother reading it at all. This is a shame, since it clearly explains that the amount solar energy entering the tropical oceans is a variable, governed by cloud cover variations which are in turn, influenced by ENSO. Ukpahonta's excellent 'ENSO 101' does not require any magical creation of heat energy - it's right there before your eyes.

    You persist in saying that ENSO must have a net neutral effect since it is an oscillation. Tisdale specifically explains why this is not the case. Presumably you already know that ENSO is difficult (impossible beyond a year or so) to predict. That in itself shows that ENSO isn't a self contained system working to clockwork precision, alternating in a simple fashion. The release of stored ocean heat during el nino is complex, as it can dissipate in a variety of ways, over different distances and timescales.

    Not for one minute did I expect you to simply accept Tisdale's alternative theory for the cause of the late 20thC warming. What had I hoped though, is that through reading the Tisdale post, you would no longer misrepresent ENSO as some sort of clockwork style, one cancels out the other, must be net neutral oscillation - it clearly isn't. Neither is it rocket science to understand this principle. Figuring out it's overall contribution to observed warming - yes, that's another matter.

    Ukpahonta - nice job with your ENSO 101

    jkiller - I'm with you. Intuitively, expected the numbers to be lower for the UK than those posted above.

  • Comment number 15.

    Anybody see the meteors last night? Sounds like a great display.

  • Comment number 16.

    15. - lateintheday wrote:
    "Anybody see the meteors last night? Sounds like a great display.
    This could have been a bolide/fireball or some space debris re-entering the atmosphere. Personally I think the latter as it was relatively slow.
    Either way, unpredictable, so the chance of seeing them was very low.
    More likely to be seen by late night revellers than amateur astronomers.
    Normaly meteors only last for a second or so and these seem to have lasted for about 1 minute, long enough for people to get their mobile phones out.

  • Comment number 17.

    14. lateintheday wrote:

    "newdr54 - it is apparent from your posts that you either briefly 'scanned' the Tisdale post or did not bother reading it at all. This is a shame, since it clearly explains that the amount solar energy entering the tropical oceans is a variable, governed by cloud cover variations which are in turn, influenced by ENSO."

    It must be me, because I still have no idea how that process is supposed to explain the bulk of the global surface warming observed since the mid 1970s? Nobody is claiming that ENSO doesn't shift heat between the atmosphere and the ocean. If that's all Bob Tisdale is claiming, then I don't know who he thinks he's disagreeing with.

    And I did not at any time refer to ENSO as a 'clockwork mechanical process'. I referred to it by its name - an *oscillation*. An oscillation, according to Wikipedia, is "the repetitive variation, typically in time, of some measure about a central value (often a point of equilibrium) or between two or more different states." Therefore, by their nature, oscillations in ocean cycles that absorb and redistribute heat must have a net neutral influence on climate over time, otherwise they wouldn't be called 'oscillations'.

    "jkiller - I'm with you. Intuitively, expected the numbers to be lower for the UK than those posted above."

    Thankfully we don't have to rely on intuition.

  • Comment number 18.

    #17 newdr54

    ENSO does the opposite of what you described, heat from the ocean is moved to the atmosphere. The amount of heat depends upon how much the ocean has absorbed from the sun, this varies as to how much cloud cover there is. Less cloud more energy into the system, higher OHC, higher surface temperatures, higher temperature in the troposphere. More cloud, less energy into the ocean, more energy reflected out of the system, cooler OHC, cooler surface temperatures, cooler troposphere.

    Think of it as one way traffic, from the sun into the ocean, from the ocean into the atmosphere, from the atmosphere into space.

    The relationship to TSI can be observed in the out going long wave radiation. If there is an increases in outgoing radiation without an increase in TSI then there is more energy being reflected out, from clouds, and less going into the system.

  • Comment number 19.

    18.Sep 2012, ukpahonta:

    As I said @17, as far as I know ENSO shifts heat *between* the atmosphere and the ocean; I didn't intend to suggest that I thought it was all one-way traffic. I think we are more or less agreed on the mechanics of the ENSO system.

    I have to admit at this point that lateintheday was right; I didn't read through Tisdale's (very long!) post at WUWT. I just read the intro and conclusions.

    I have now printed the whole thing off and am currently struggling through it, making notes as I go. I have to say the start has not been encouraging.

    So far he has, in so many words, said that "climate scientists" (for apparently they are a collective) are perpetuating "myths" about CO2 warming the oceans, and are all "alarmists" and "liers".

    Also, climate scientists all (again, they are a collective, apparently) perpetuate "falsehoods" and "fairy tales"; they "manufacture" data; they are "goofy" and "attempt to conceal" evidence.

    Bob Tisdale seems to think there is (and I hesitate to use the term given recent blogosphere events) a *conspiracy* against him and his views.

    But I'll persevere, aided by a few gin and tonics (it's Saturday, and it's after 9 am...)

  • Comment number 20.

    Have fun.

  • Comment number 21.

    The web local forecasts for the NE seem to be showing an earlier onset of the strong winds and increased wind speeds on Monday.
    Still the only weather warnings being issued seem to be for rain, with no warnings related to strong winds, which I personally feel is more of a threat.

  • Comment number 22.

    20. ukpahonta:

    I can't say it was fun, but I eventually got there.

    As I understand Bob Tisdale's essay posted on WUWT, he is claiming that El Nino events have been responsible for most of the global land and ocean surface warming observed since 1980. This is because, he says, it takes the global oceans a long time to cool down after El Ninos (Fig. 8), and this risidual heat accumulates, apparently without dissipating fully, so each subsequent El Nino creates a sort of 'step function', whereby overall ocean temperatures continuously rise (Fig. 10).

    I don't see where in the essay Tisdale explains the mechanism whereby this heat fully dissipates from the oceans, but presumably he accepts that it eventually must (otherwise oceans would just continuously accumulate heat).

    Looking back over the ENSO data (http://www.bom.gov.au/climate/current/soihtm1.shtml%29 and comparing it with HadSST2 (http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2gl.txt%29 the ENSO trend (1887 to present) is flat (actually slightly negative overall, R^2 = -0.0005); whereas the SST trend over the same period is strongly positive overall (R^2 = +0.5803).

    So over the longer term the apparent correlation between ENSO and SSTs is not sustained. ENSO has fluctuated between El Nino, ENSO neutral and La Nina states more or less evenly since 1887. SSTs have seen a few ups and downs, but overall have risen quite strongly during that period. Tisdale is vastly overstating his case when he claims that ocean warming is fully natural and caused by ENSO.

  • Comment number 23.

    #22 newdwr54

    Can't say that your ability to find an earth shattering problem with Tisdale's life time work after one nights study was unexpected.

    Firstly the ENSO data that you refer to at http://www.bom.gov.au/climate/current/soihtm1.shtml, once you remove the end bracket, gives me a listing of the Southern Oscillation Index (SOI) which is based on pressure differences between Darwin and Tahiti. This is an indication of ENSO conditions and not a measure of temperatures

    Secondly you then compare the REGIONAL pressure difference with GLOBAL sea surface temperature data from http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2gl.txt ,once you remove the end bracket.

    Perhaps you should refer to:
    to give an indication of like for like in the modern era and relate the data for the 'rest of the world',
    back to the nineteenth century with your HadSST2 data, marking ENSO events from your pressure data.

    I await to see the graphs that you produce for pre-satellite data back to 1850. I'm sure that you could post them at Bobs site and he may even thank you for the effort.

  • Comment number 24.

    to QV#11; newdwr54#13; lateintheday#14

    Thanks all for the year temp info. Yes I was refering to the local temp not the global. I have to say I am a bit surprised by the relative warmth of the year.

    However, I guess under cloudy wet conditions, night time temps may also be higher which will affect the mean. How well an average can confound perception!

    Regarding the "natural signs" it just goes to show the subtleties that may be involved - for example direct sunshine levels (important for many invertebrates); degree of wetness (significant for disease); combinations of the above for food foraging. Our swallows only had one brood this year (normally 2) and there have been many reports of summer migrants "giving up" and going back south prematurely not to mention many other species simply being flooded out.

    I have a warmth loving exotic tree in my garden which has failed to flower for the first time in 12 years. I would be surprised if maize ripens this year on the Vale of York (it often does) - on the Wolds much of it hasn't even flowered yet! Will the sweet chestnuts ripen as they have regularly in recent decades? etc etc.

  • Comment number 25.

    'A cool-water anomaly known as La Niña occupied the tropical Pacific Ocean throughout 2007 and early 2008. In April 2008, scientists at NASA’s Jet Propulsion Laboratory announced that while the La Niña was weakening, the Pacific Decadal Oscillation—a larger-scale, slower-cycling ocean pattern—had shifted to its cool phase.'

    'Unlike El Niño and La Niña, which may occur every 3 to 7 years and last from 6 to 18 months, the PDO can remain in the same phase for 20 to 30 years. The shift in the PDO can have significant implications for global climate, affecting Pacific and Atlantic hurricane activity, droughts and flooding around the Pacific basin, the productivity of marine ecosystems, and global land temperature patterns. #8220;This multi-year Pacific Decadal Oscillation ‘cool’ trend can intensify La Niña or diminish El Niño impacts around the Pacific basin,” said Bill Patzert, an oceanographer and climatologist at NASA's Jet Propulsion Laboratory, Pasadena, Calif. “The persistence of this large-scale pattern [in 2008] tells us there is much more than an isolated La Niña occurring in the Pacific Ocean.” '

    'Natural, large-scale climate patterns like the PDO and El Niño-La Niña are superimposed on global warming caused by increasing concentrations of greenhouse gases and landscape changes like deforestation. According to Josh Willis, JPL oceanographer and climate scientist, “These natural climate phenomena can sometimes hide global warming caused by human activities. Or they can have the opposite effect of accentuating it.” '

  • Comment number 26.

    ' Regardless of the mechanism(s) causing shifts in the PDO and ENSO, the results presented in this paper confirm that a relationship does exist between the frequency of El Niño and La Niña events and phase changes in the PDO, prior to the 20th Century. In fact, this relationship appears to have been stable over the last 16 phase changes of the PDO. The implications of these findings are particularly important in the light of the recent spate of El Niño events, which have been reported as unusual, and have even been suggested to be possible evidence of anthropogenic climate change [e.g., Trenberth and Hoar, 1996]. However, the paleo records suggest that the apparent lack of La Niña events and high frequency of El Niño events over the past two decades may not be abnormal and could be attributed to the fact that during this time the PDO has been in a positive phase. When the PDO switches back to a negatively dominated phase, it is quite likely that the frequency of La Niña events will increase once again. However, if anthropogenic climate change was to dominate natural variability in the future, resulting in a persistent warm period similar to the positive phase of the PDO, then it is possible that we may see a sustained period of permanently elevated El Niño occurrence.'

  • Comment number 27.

    The wind is currently building up in speed in the NE, but still not as strong as forecast so far.
    On the other hand, forecasted speeds for this afternoon and evening have been
    increased since yesterday.
    A confusing picture.

  • Comment number 28.

    More info on Northern Hem ENSO teleconnections, I will have to read through a few more times. "Stratospheric sudden warmings" are all new to me!

    "Why might stratospheric sudden warmings occur with similar frequency in El Nino and La Nina winters?" Draft Aug 6th 2012


    H/T Bob Tisdale at WUWT

  • Comment number 29.

    Have the MO issued any seasonal rainfall forecasts recently?
    I thought I could remember one being posted here, but I can't find it.

  • Comment number 30.

    @29 QV

    Paul Homewood posted Sep=Oct-Nov on the previous thread:-


    and temp:-


    I have just had a look at present Sept Nos well down up till 22nd:-


    Certainly about to change!

  • Comment number 31.

    Winter Weather Outlook 2012/13 – Issue 1

    Includes Sudden Stratospheric Warming and Met Office Precipitation charts!

  • Comment number 32.

    Thanks for the links, I don't know how I missed them.

  • Comment number 33.

    Enso Wrap up today:-

    "Odds of El Niño ease, but risk remains"


    Whilst shown as "not available" in the Wrap Up the MO have posted their Sept GloSea Enso model prediction:-


    The outlook shows a further reduction in their expectation of El Nino folowing on from their August which also showed a reduction.

    Don't know which way this will go, the OLR/Cloudiness "indicator" still tracking 2009 very closely and 2009 ended with a transition into El Nino:-


    "Cloudiness along the equator, near the Date Line, is an important indicator of ENSO conditions, as it typically increases (negative OLR anomalies) near and to the east of the Date Line during an El Niño event and decreases (positive OLR anomalies) during a La Niña event."

  • Comment number 34.

    Reports that we will get a month's rainfall in 24 hours is total alarmism. Which month? Which part of the country?
    Given the wide rainfall variation across the country, Cumbria to Lincolnshire for example, I feel compelled to ask those questions.
    The BBC does itself no favours with reports like this.

  • Comment number 35.

    Last night the rain alarmism was modified to a month, September, but again not any particular part of the UK. An add on was that the last time such September rainfall happened was 30 years ago.
    Not a one off event then. In the mean time more building on flood plain, more concrete ground cover and no river dredging. The recipe for flooding increases.

  • Comment number 36.

    I presumed that they meant that in "some locations", the daily rainfall could reach the equivalent of the whole of September's normal rainfall but I don't think that would be exceptional. I have personally recorded rainfall figures in my garden, of about 30mm on the 24th and 44mm on the 25th, compared to a total of 41.4mm in September 2011, 88.5mm in 2010 and 50.7mm in 2009, but that's as far as my records go back.
    It is also being said that it is the worst storm over the UK as a whole for 30 years, but I haven't heard a precise date for that claim. Personally my impression is that we used to get longer periods of sustained rainfall in the 1950's and 1960's.
    The average monthly rainfall in England & Wales for September is about 75mm and there has never been that much in a single day, since 1931, (when daily records begin), and I don't expect it on this occasion.
    The highest daily rainfall figure for September since 1931 appears to have been 43.23 mm on September 25th 1986, with a further 5.94 mm on the following day, which is about 26 years ago, so I don't know whether that was the event being referred to. It will be interesting to see how this compares with the rainfall figure from this event.

  • Comment number 37.

    Moreover, when the weather is exceptionally cold and appears to contradict "climate change" claims, we are often told by proponents of "climate change" not to confuse weather with climate.
    However, that doesn't stop those proponents using examples of bad weather as "proof" that climate change is happening and I expect someone will do that about this weather.
    More insidious is the fact that a lot of people have been so indoctrinated by talk of "climate change" that they now automatically assume that
    bad weather such as this, is caused by "climate change".

  • Comment number 38.

    Just thinking about it a bit more, a rainfall figure of 43.23mm over the entire area of England & Wales, is an awful lot of water.
    Perhaps someone can work out what that is in tonnes!

  • Comment number 39.

    @38 QV

    "work out what that is in tonnes!"

    No thanks, but I think it might have cleared out the red shading on the following "drought map":-


  • Comment number 40.

    I've just noticed that the figure of 43.23mm which I quoted in my post #36 above, was actually on the 25th of August 1986, not September.

  • Comment number 41.

    'WAITING for solar fireworks to reach a grand finale next year? Um, sorry, looks like you already missed them. Structures in the sun's corona indicate that the peak in our star's latest cycle of activity has been and gone, at least in its northern hemisphere'


  • Comment number 42.

    @ 41 QV

    Thanks for the link, apart from the interesting relative mismatch in the hemispheres I notice "sudden stratospheric warming" is referenced again? Time to read some more.

  • Comment number 43.

    Sorry ref should be @ 41 ukpahonta!

    Matron threatening to restrict router use!

  • Comment number 44.

    on post 37:

    Cool first, warm later
    Posted on September 22, 2012
    by Judith Curry

    From an article in the New Scientist by Fred Pearce, written in Sept 2009:

    One of the world’s top climate modellers said Thursday we could be about to enter one or even two decades during which temperatures cool.

    “I am not one of the sceptics,” insisted Mojib Latif of the Leibniz Institute of Marine Sciences at Kiel University, Germany.
    “However, we have to ask the nasty questions ourselves or other people will do it.”

    Asking questions is at the heart of the scientific method, and science has been characterized as ‘organized scepticism.’
    The questions are referred to as ‘nasty’, since presumably they are inconvenient for the audience (the UN).
    Not wanting to be identified as a ‘sceptic,’ in spite of the fact that the perspective that he presents is consistent with
    with what many sceptics say. There is a ‘we’ versus ‘other people’ , in terms of who is acceptable in terms of
    asking questions. If this doesn’t define climate tribalism, I don’t know what does.
    On issues of climate projection for the next few decades and late 20th century attribution, I suspect that there is little
    that Latif and I would disagree on. The big difference is that Latif has maintained his status in the climate community that identifies itself with UN programmes (e.g. IPCC, WCRP) by insisting that he is not a sceptic. Whereas people are increasingly labeling me as a ‘denier’ because I engage with sceptical individuals from outside the UN climate community.

    (( The above should make one wonder! ))

  • Comment number 45.

    I carried out a study of the Boscastle flood and local rainfall figures were from poor coverage. In fact the rainfall figure taken for Borcastle on the day were from a separate though adjoining catchment. There were no accurate official figures for the Boscastle catchment. The nature of the storm that caused this flood means that local severe rain will not be measured even with local catchment data so making local mitigation planning difficult if not impossible. The same will probably be true for the rest of the country.

  • Comment number 46.

    John Marshall,



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