The La Niña has strengthened, now near 2008 levels

Update:  it appears that the September values of the Tahiti-Darwin SOI (+25) and Klaus Wolter Multivariate ENSO Index (MEI) are at historical levels when compared to previous Septembers, with the SOI only showing a higher September value (+29.7) back in 1917!

From the Australian Bureau of Meteorology, the trace is now at a comparable level to the 2008 La Niña, though the onset is more rapid:

Issued on Wednesday 13 October

The La Niña in the Pacific remains a moderate to strong event. The Southern Oscillation Index (SOI) value of +25 for September was its highest monthly value since 1973 [Ryan Maue adds here:  the September value of +25 is the highest value for that month since 1917, the only other time it has been exceeded according to the Tahiti-Darwin SOI data back to 1876], while central Pacific Ocean temperatures are comparable to those observed during previous moderate events, such as 2007 and 1998. Long-range models surveyed by the Bureau suggest that this La Niña will persist into at least early 2011.

ENSO indicators remain firmly at La Niña levels. The central Pacific Ocean is more than 1°C cooler than the long-term mean at the surface, while temperatures below the surface are up to 5°C cooler than normal. The SOI remains above +20, which places it in the top 5% of observed values. Although trade winds are stronger than normal over the western Pacific and cloudiness over the central and western Pacific continues to be suppressed, a strong Madden Julian Oscillation (MJO) may weaken some of these indicators over the coming fortnight.

La Niña periods are generally associated with above normal rainfall during the second half of the year across large parts of Australia, most notably eastern and northern regions. Night time temperatures are historically warmer than average and Tropical Cyclone occurrence for northern Australia is typically higher than normal during the cyclone season (November-April).

A negative IOD event is also underway in the Indian Ocean. Negative IOD events are typically associated with above average rainfall over large areas of southern Australia during spring. IOD events usually decay in the months of November and December with the onset of the Australian monsoon.

Click image to go to BOM page or see our WUWT ENSO/SST page here

h/t to Geoff Sharp

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39 Responses to The La Niña has strengthened, now near 2008 levels

  1. vukcevic says:

    On the opposite side in the Arctic, there are also signs of cold winter on the way. There is a hot spot developing in the Labrador Sea due to release of heat into atmosphere from a brunch of Gulf Stream.
    http://weather.unisys.com/surface/sst_anom.gif
    This could move polar jet-stream further south than normal, implying colder winter for the North Atlantic areas.

  2. David says:

    “The central Pacific Ocean is more than 1°C cooler than the long-term mean at the surface, while temperatures below the surface are up to 5°C cooler than normal”

    Is the 5C cooler typical for a La Nina of this degree?

    Thanks in advance.

  3. Pingo says:

    Brr. Snow expected in England next week – look out for london grinding to a halt in another October!

  4. Les Francis says:

    Some more bon mots from the Australian B.O.M.
    They have just realized that there is such a thing as the U.H.I.

    Hot Cities

  5. Ian W says:

    David says:
    October 14, 2010 at 2:42 am
    “The central Pacific Ocean is more than 1°C cooler than the long-term mean at the surface, while temperatures below the surface are up to 5°C cooler than normal”

    Is the 5C cooler typical for a La Nina of this degree?

    Yes – I picked that up too. From the track of cold water around Bermuda where hurricane Igor passed by more than a month ago, it looks like the Atlantic hasn’t got any warm water below the surface either.

    This could be investigated if NOAA would allow the ARGO data to be accessed. The ARGO teams seem to be unwilling to release details of the ocean temperatures. One wonders why this is.

  6. rbateman says:

    Local meteorologists are telling us that the rains are set to begin in 10-14 days for California. We are wondering what kind of storms they will be given the colder Sea temps of La Nina.

  7. Bob Tisdale says:

    They illustrated NINO3 region (5S-5N, 150W-90W) SST anomalies in the graph above. It’s a little east of the NINO3.4 region (5S-5N, 170W-120W) which is more commonly used. The NINO3.4 SST anomalies this year have been well below the levels of the 2007/08 La Nina since May/June:
    http://i53.tinypic.com/sls9k8.jpg

    For those who missed it a few days ago, here’s a link to the monthly SST update for September:
    http://bobtisdale.blogspot.com/2010/10/september-2010-sst-anomaly-update.html

  8. Bob Tisdale says:

    Anthony: Shouldn’t the headline read “2007 levels”? The La Niña that year straddled 2007/08. Similarly, this one will straddle 2010/11.

  9. stephen richards says:

    None of the BOM/world models were showing any predictions below 1.5° earlier this summer. Now they are all heading south. Good stuff these models, eh.

  10. stephen richards says:

    Les Francis says:
    October 14, 2010 at 3:31 am
    Some more bon mots from the Australian B.O.M.
    They have just realized that there is such a thing as the U.H.I.

    They are soooo passé. They make it sound like they have just discovered something wonderful. Scientist? more like idiots.

  11. stephen richards says:

    rbateman says:
    October 14, 2010 at 4:26 am
    Local meteorologists are telling us that the rains are set to begin in 10-14 days for California. We are wondering what kind of storms they will be given the colder Sea temps of La Nina.

    In southern france we are desperate for some rain. 3 consequtive years of drought means my house has started to move again having been piled following the droughts of 2003, 2005, 2007-10.

  12. stephen richards says:

    Bob Tisdale

    What are your thoughts on the 5°c, the overhang of global temps during this niña fall??

  13. Tenuc says:

    What we don’t seem to know yet exactly what drives these quasi-regular fluctuation in and above the tropical Pacific Ocean. Therefore, nor do we know for certain what relationship these events have with long-term weather. Contrary to some commentators’ beliefs (or prejudices), we cannot yet say whether the strengthening La Nina will affect the NH winter to make it colder as the previous La Nina didn’t cause warm conditions in UK and US. Must be some other confounding influence?

  14. stephen richards says:

    Pingo says:
    October 14, 2010 at 3:07 am
    Brr. Snow expected in England next week – look out for london grinding to a halt in another October!

    That would be about 20 Oct. according to GFS. http://www.theweatheroutlook.com/twodata/datmdlout.aspx

  15. lotto says:

    Anthony: Shouldn’t the headline read “2007 levels”? The La Niña that year straddled 2007/08. Similarly, this one will straddle 2010/11.

  16. Phil's Dad says:

    vukcevic says:
    October 14, 2010 at 2:10 am
    “…a brunch of Gulf Stream.”

    Low calorie cirtainly but a little salty for my taste.

  17. Ken Hall says:

    Of course none of the models predicted this. They were all following the ‘El Nino hottest year on record’ meme.

  18. jackstraw says:


    When the rains come to California, then snows come to the Rockies. My snowmobiles are ready, the wood is stacked high, my phat skis are ready. I hope it is another epic powder year like it was the last La Nina.

  19. PeterW says:

    I can’t hear the Com’ Games closing ceremony on the tele because of the rain on my tin roof – dams are full, tanks are full and ground is saturated.

    That’s enough for this year Gaia, the wheat needs to ripen now…

    Rivers are breaking their banks, major water catchment dams are spilling at over 4 metres over the wall.

    Must be climate disruption… Better tax carbon dioxide because… we…

    Oh I just give up…

    It is after all the hottest year on record…

    Not.

  20. Douglas Dc says:

    Hurt my leg last year when the PacNW had a nino winter, this year I’m goin’ Skiin’….

  21. Breckite says:

    jackstraw says:
    October 14, 2010 at 6:51 am
    “When the rains come to California, then snows come to the Rockies. My snowmobiles are ready, the wood is stacked high, my phat skis are ready. I hope it is another epic powder year like it was the last La Nina.”

    jackstraw, where are you in the Rockies? During the 2007/2008 La Niña many ski areas in Colorado had record snowfall. It was one of my best seasons ever in my 28 years of skiing. I’m praying for a repeat this season – my Fat-ypus D-Senders are ready.

  22. vukcevic says:

    Phil’s Dad, I did see spelling error, but once is up there it was too late, I was having a late breakfast at the time. It would be useful if one can edit minor errors while post is awaiting moderation.
    I hope Phil is a good boy.

  23. John F. Hultquist says:

    rbateman says:
    October 14, 2010 at 4:26 am
    Local meteorologists are telling us that the rains are set to begin in 10-14 days for California.

    Is that unusual? Perhaps a little early? In any case, isn’t a La Niña winter expected to bring less rain to California?

    I also wonder what the “local meteorologists” know. I don’t see that the NWS folks out of LOX are expecting much:
    http://www.wrh.noaa.gov/lox/scripts/getprodplus.php?sid=lox&pil=afd&back=yes

  24. jorgekafkazar says:

    vukcevic says: “Phil’s Dad, I did see spelling error, but once is up there it was too late…”

    We all knew what you meant, Vuk. It’s not important.

  25. geo says:

    Yes, but where’s the impact on the global anomally? Even Roy Spencer is scratching his head over that one.

  26. Ryan Maue says:

    The MEI index has the La Nina ranked number 1 most intense for the AUG/SEP period — with data since 1950.

    The most recent (August-September) MEI value shows a continued drop from earlier this year, reaching -1.99, or 0.18 sigma below last month’s value, and 3.39 standard deviations below February-March, a record-fast six-month drop for any time of year, while slowing down a bit at the shorter time scales. The most recent MEI rank (lowest) is clearly below the 10%-tile threshold for strong La Niña MEI rankings for this season. One has to go back to July-August 1955 to find lower MEI values for any time of year.

    Read more here: http://www.esrl.noaa.gov/psd/people/klaus.wolter/MEI/

  27. Bob Tisdale says:

    stephen richards says: “What are your thoughts on the 5°c, the overhang of global temps during this niña fall??”

    If I don’t give the answer you’re looking for, please clarify your questions. If you’re referring to the -5 deg C subsurface anomalies in the eastern equatorial Pacific, then Sept 2010…
    http://i51.tinypic.com/a3p82h.jpg

    …appears lower than Sept 2007…
    http://i55.tinypic.com/15x0sx5.jpg

    …and appears lower than Sept 1988…
    http://i54.tinypic.com/29fcnpy.jpg

    …but it’s more in line with Sept 1998:
    http://i53.tinypic.com/6z31iw.jpg

    The ECMWF Zonal Section graphics are available here:
    http://www.ecmwf.int/products/forecasts/d/charts/ocean/reanalysis/xzmaps/Monthly/

    And if your question about overhang has to do with the lag in the drop of global temperatures in response to the La Niña, I wrote a post about that subject a month ago. I’ll update it toward the end of the year. I don’t believe there’s anything unusual about the lag so far this year, but it’s still early:
    http://bobtisdale.blogspot.com/2010/09/declines-in-global-temperatures-from-el.html

  28. kalsel3294 says:

    JAMSTEC are predicting that the La-Nina will persist until early 2012. http://www.jamstec.go.jp/frcgc/research/d1/iod/sintex_f1_forecast.html.var

    Interestingly other commentators are now comparing the present conditions in Australia as comparable to conditions in 1974 which was the beginning of 3 consecutive La-Nina years that produced the wettest period since records began, and possibly since settlement.
    What makes that even more interesting to me is that in 2006/2007 whilst BOM were strongly forecasting the imminent arrival of a La-Nina, JAMSTEC were observing, and correctly predicting conditions developing in the Indian Ocean that approximated the unusual conditions there in 1967. 1967 for those in SE Australia became at the time a benchmark for bad droughts.
    It will be interesting to see if the next few years become a repeat of the cycle that occurred 40 years ago.

  29. Cam says:

    We’re LOVING IT here in south-eastern Australia. The drought is well n truly over, dams are at their highest levels in over a decade, some areas have had their best rainfall in over 30 years…. And yet the ‘climate change hysterics’ in this country, many who earlier this decade said some of our capital cities would run out of drinking water by 2010, get off scot-free. And now we have Government sycophants like Wil Steffen desparately trying to keep the scare going this week by using lies to say that sea level rises are still headed for a 1 meter rise by the end of the century, when all the data available supports nothing more than a few inches.

    With continual reduced solar activity, a negative IOD situation in the Indian Ocean, and a strong La Nina, real scientists are expecting the wet conditions to continue right into the new year. Yey!!

  30. Matt Rogers says:

    As in 2008, La Nina will cool the planetary temperature. Remember in 2008, there was considerable talk of “no net warming in ten years” because the global temperature fell to the lowest levels of the decade (near normal on the satellite-based estimates). This should happen again.

  31. The Monster says:

    Am I the only person who noticed that “The La Niña” literally means “The The Girl”? It’s not quite as bad as “The Los Angeles Angels” (“The The Angels Angels”), or “use your PIN Number at the ATM Machine”….

  32. phlogiston says:

    Bob,

    The last link in your reply to Stephen Richards described persistent elevated SSTs in the west Pacific and Indian oceans, continuing from the recent 2009-2010 el Nino, as a reason for the “TLT overhang”. In previous posts you explained the ENSO heat turnover in which OHC is lost during an el Nino and recovered during a La Nina. Could these currently persistent raised SSTs reduce the recovery of OHC in the present La Nina? Or have I picked up the wrong end of the stick? Thanks in advance.

  33. Bob Tisdale says:

    phlogiston says: “Could these currently persistent raised SSTs reduce the recovery of OHC in the present La Nina?”

    First, let’s discuss the surface. The East Indian and West Pacific Ocean SST anomalies increase first because the El Niño causes changes in atmospheric circulation and these changes had travelled east and have finally made it to that part of the world. Then they are warmed because the water that had been released from below the surface of the Pacific Warm Pool during the El Niño is returned to the East Indian and West Pacific Oceans by the increased trade winds during the La Niña but some of that warm water remains on the surface. Also during the La Niña the stronger-than-normal trade winds also decrease cloud cover and allow more downward shortwave radiation to heat the tropical Pacific. This maintains SST anomalies in the East Indian and West Pacific Oceans at the elevated levels because the trade winds are pushing these additional warm waters to the west and then poleward when they run into the Indonesian land mass. And some of that warm water makes its way through the gap between Australia and Indonesia and into the East Indian Ocean.

    And now to answer your question: I don’t see how that would happen. The tropical Pacific OHC is also recharged during the La Niña and this is again a function of the decrease in cloud cover and increase shortwave radiation due to the increased strength of the trade winds.

    I wish I was a cartoonist. That process would be wonderful to illustrate with a series of them.

  34. Bill Illis says:

    In addition to the warm water of the former El Nino being pushed toward the Western Pacific and through Indonesia into the Indian Ocean, some of the warm water has been also pushed down below and also north into the north Pacific Ocean – Kuroshio Current.

    The Pacific cross-section at 165E (from 40N to 40S) – Pretty impressive amount of hot ocean water given the strong La Nina.

    http://www.ecmwf.int/products/forecasts/d/charts/ocean/real_time/yzmaps!20101014!Anomaly!Temperature!165E!/

    While ocean heat gets released to the atmosphere/space and the ocean gets recharged by the Sun/warm atmosphere, some of this water just keeps re-circulating within the oceans. There are all kinds of ocean currents that go east-west, or west-east at different latitudes and they might go the opposite direction in the subsurface.

    While there are dominant ones like the Pacific equatorial, the Kuroshio or the Gulf Stream, as we move to higher and higher resolution, there are actually striation patterns in the ocean currents. As in this map where red is west-east and blue is east-west. The north equatorial counter-current, which has a big impact on the ENSO, looks to be the strongest striation in this map (which leaves out some of the areas where the more dominant currents operate).

    http://oceanjets.org/img/jets.jpg

  35. Pascvaks says:

    Ref – Bill Illis says:
    October 15, 2010 at 5:58 am

    Anyone have a good feel for how well we’re doing actually monitoring ocean currents (surface and deep) these days? Get the “impression” we’re doing better extraterrestially(sp?) that we are on Terra Firma. Or, is this another megasupercomputer software program simulation now that we don’t even bother stepping outside to check?

  36. George E. Smith says:

    “”” Bill Illis says:
    October 15, 2010 at 5:55 am
    …………………………………
    While ocean heat gets released to the atmosphere/space and the ocean gets recharged by the Sun/warm atmosphere, some of this water just keeps re-circulating within the oceans. ……………………….

    While there are dominant ones like the Pacific equatorial, the Kuroshio or the Gulf Stream, as we move to higher and higher resolution,……………….. there are actually striation patterns in the ocean currents. ………………….As in this map where red is west-east and blue is east-west. The north equatorial counter-current, which has a big impact on the ENSO, looks to be the strongest striation in this map (which leaves out some of the areas where the more dominant currents operate).

    http://oceanjets.org/img/jets.jpg “””

    My dot streams added either in lieu of deletions or for emphasis.

    So Bill, as to Ocean heat getting recharged by the “Sun/warm atmosphere” as you state; which certainly seems to be the standard dogma, do you have any even rough numbers for those two components; i.e. the sun and warm atmosphere.

    The sun part is rather obvious, and I would expect something ranging from about 1000 W/m^2 down to some obliquity factor of that; given that the (deep) oceans are a pretty good black body imitation; well of about 0.97-8 absorptance (for solar spectrum radiation).

    The “warm atmosphere” contribution though is where I think there is contention; and I confess I have not even a rough idea for what W/m^2 is even fashionable for that.

    The “Warm atmosphere” energy contribution, would arguably be some sort of direct thermal contact conductive component plus the LWIR down radiation component. BOTH of those energy sources would seem to be deposited right in the surface film of the water; less than about 50 microns total absorption length for the radiation,a nd even less than that for the conducted “heat”.

    So in both instances that source of energy would seem to simply promote surface evaporation; and hence significant latent heat loss to the atmosphere.

    So I have a natural reticence to believe there is much “warm atmopshere” contribution to the total heat IN THE DEEPER OCEAN WATERS. But I have NO IDEA AT ALL just what level of such contribution there is.

    So if you have any numbers; even rough ones Bill it would be really helpful to know what really is the downward LWIR W/m^2 to compare with the solar, and how much of that sticks in the form of net W/m^2 into the deeper ocean; and also what the interface conducted heat from the warm atmosphere really is.

    I have never had the impression that there is a full realization of the significance of the wavelength shift from the incoming solar spectrum energy to the atmosphereic thermal radiation spectrum (downwards) and how that affects what happens at the ocean surface.

    Thanks for any enlightenment Bill.

    George

    PS I forgot to add those striated patterns are wonderful. While it is easier for our minds to grasp simple one dimensional thermal gradients and the like; it seems that Mother Gaia just does not like things looking alike for too great a distance;so she forces these pattern break ups, Well those recent NASA cloud cell patterns; which I just verified at the stick in the sand level on my recent daylight round trip to Hawaii; are another example of the same thing.

    I seem to recall that Sir James Jeans or someone else, actually did some sort of calculation that proved that you can’t have a body of matter greater than some certain amount that is stably uniform; so that beyond some mass limit, it must break up; which in the astronomy case, leads to gravitational collapse that results in star formation. Maybe Leif Svalgaard has that one at his fingertips.

    Something along the same lines evidently causes your SST striations; and the cloud cellular structure as well.

  37. Bill Illis says:

    George E. Smith says:
    October 15, 2010 at 11:29 am
    “”” Bill Illis says:
    October 15, 2010 at 5:55 am

    So Bill, as to Ocean heat getting recharged by the “Sun/warm atmosphere” as you state; which certainly seems to be the standard dogma, do you have any even rough numbers for those two components; i.e. the sun and warm atmosphere.
    ———————-

    This turns out to be very counter-intuitive. Tropical convection clouds drive the system.

    When there is a La Nina, huge amounts of energy are actually escaping to space (not only in the ENSO regions but covering the entire Tropics). There is no cloud cover to hold the energy in.

    When there is an El Nino, huge amounts of energy are being held-in the atmosphere (by clouds again).

    These numbers completely dwarf anything proposed for doubling GHGs for example.

    Right now, at the International Date Line area 5N to 5S, outgoing long-wave radiation is 24 watts/m2 above average (and can vary by as much as +/-35 watts/m2 over a monthly period). This very closely follows the ENSO.

    http://img87.imageshack.us/img87/8633/ensovsolrsept10.png

    Lets extend that to the entire Tropics between 20N to 20S, (an area which represents 41% of the total solar energy received by the Earth), the outgoing long-wave radiation is also extremely high at 12 watts/m2 above average (and this can vary by +/- 25 watts/m2 as a monthly average).

    http://img684.imageshack.us/img684/6536/ensovsequatorialolrjuly.png

    The ENSO area has enough change by itself (and influences other areas by enough) that it is the big driver of the OLR changes in the Tropics.

    So, the conclusion is that during a La Nina, the atmosphere is really cooling off, (and there is much less overall cloud cover in the Tropics – none in the Pacific and much above normal over Indonesia but on average for the whole Tropics, it is much below average). Less cloud means the colder Tropics water are absorbing more Solar energy.

    In an El Nino, the atmosphere is warming up and there is more cloud cover and less solar energy being absorbed.

    The numbers themselves are so big that this little ENSO phenomenon completely dwarfs the impact from increased GHGs. Over the long-term, there has been no change in the ENSO, so maybe these huge swings balance out over the long-term while with increased GHGs, they may not.

    But one cannot say that the ENSO is not a very important factor in the climate.

  38. E O'Connor says:

    The latest ENSO update by BoM was posted today –
    http://www.bom.gov.au/climate/enso/

    “All ENSO indicators continue to exceed La Niña thresholds. The tropical Pacific Ocean remains significantly cooler than average for this time of year, with NINO indices recording their lowest October values since the La Niña event of 1988. Below the Pacific Ocean surface, temperatures are up to 4°C cooler than normal.”

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