April 2016 ENSO Update – La Niña Alerts Issued for Later This Year and NINO1+2 SSTa Are Near Zero Deg C

Guest Post by Bob Tisdale

This post provides an update of many of the ENSO-related variables we presented as part of the 2014-15 El Niño Series.  For the posts about the 2015/16 El Niño, we’ve used the evolution years of different El Niños as references to the goings-on in 2015 and 2016.  This month we’re including the 1997/98 El Niño because it was the strongest El Niño in our short instrument temperature record.  For the other reference, we’re using 1982/83, which was the second strongest El Niño.

INTRODUCTION

The sea surface temperature anomalies for the easternmost NINO1+2 region have dropped to near zero.  The NINO3 and NINO3.4 regions should follow soon.

Both Australia’s Bureau of Meteorology (BOM) and the U.S.’s NOAA have issued La Niña alerts for the ENSO season of 2016/17. (BOM notice is here, and NOAA advisory is here.) Keep in mind that moderately strong El Niño conditions still exist, though, and that the alert is for possible future conditions.

In an upcoming post, we’ll discuss what we might expect to happen as the tropical Pacific transitions from El Niño to La Niña.  All of that warm water released by the El Niño has to go somewhere. It doesn’t magically disappear.

In the March ENSO update, we mentioned the odd forecast for a weak El Niño from NOAA CFS.v2 model. NOAA has since discovered a glitch in the CFS.v2 model. They reported on it in the Briefing on: Operational CFSv2 Atlantic Ocean Cold Bias Problem (.pptx file).  Based on the model mean, the NOAA CFS.v2 is now forecasting a moderately strong La Niña.  See Figure Supplement 1.

Figure Supplement 1

Figure Supplement 1

Back to your regularly scheduled update…

ENSO METRIC UPDATES

This post provides an update on the progress of the evolution and decay of the 2015/16 El Niño with monthly data through the end of March 2016, and for the weekly data through mid-April, 2016. The post is similar in layout to the updates that were part of the 2014/15 El Niño series of posts here. (The series of posts about the 2015/16 El Niño is here.) The remainder of the post includes a bunch of illustrations and some gif animations, so it might take a few moments to load on your browser.  Please click on the illustrations to enlarge them.

Included are updates of the weekly sea surface temperature anomalies for the four most-often-used NINO regions. Also included are a couple of graphs of the monthly BOM Southern-Oscillation Index (SOI) and the NOAA Multivariate ENSO Index (MEI).

For the comparison graphs we’re using the El Niño evolution years of 1997/98 and 1982/83 where possible (the two strongest El Niño events during recent decades) as references for 2015/16.

Also included in this post are evolution comparisons using warm water volume anomalies and depth-averaged temperature anomalies from the NOAA TOA project website.

Then, we’ll take a look at a number of Hovmoller diagrams comparing the progress so far for the 2015/16 El Niño to the El Niños of 1982/83 and 1997/98.

NINO REGION TIME-SERIES GRAPHS

Note: The weekly NINO region sea surface temperature anomaly data for Figure 1 are from the NOAA/CPC Monthly Atmospheric & SST Indices webpage, specifically the data here.  The anomalies for the NOAA/CPC data are referenced to the base years of 1981-2010.

Figure 1 includes the weekly sea surface temperature anomalies of the 4 most-often-used NINO regions of the equatorial Pacific. From west to east they include:

  • NINO4 (5S-5N, 160E-150W)
  • NINO3.4 (5S-5N, 170W-120W)
  • NINO3 (5S-5N, 150W-90W)
  • NINO1+2 (10S-0, 90W-80W)

01 NINO Region Time Series

Figure 1

Note that the horizontal red lines in the graphs are the present readings, not the trends.

The sea surface temperature anomalies for the easternmost NINO1+2 region have dropped to near zero (+0.1 deg C).  The NINO3 and NINO3.4 regions should follow soon.  As you’ll see later in the post (Animation 1), there is not a lot of warmer-than-normal subsurface waters left below the equatorial Pacific.

EL NIÑO EVOLUTION COMPARISONS FOR NINO REGION SEA SURFACE TEMPERATURE ANOMALIES

Using weekly sea surface temperature anomalies for the four NINO regions, Figure 2 compares the goings on this year with the 1997/98 event. (That weekly data start in January 1990, so we can’t include the 1982/83 El Niño.)  While sea surface temperature anomalies in the NINO4 and NINO3.4 regions peaked higher than in 1997, the NINO1+2 and NINO3 regions lagged well behind the 1997/98 El Niño.  In other words, the 1997/98 El Niño was a stronger East Pacific El Niño than the 2015/16 El Niño.

We also showed in the post here that the differences between sea surface temperature datasets and their uncertainties keep us from knowing which El Niño was strongest.

The NINO region sea surface temperature anomalies are continuing to show declines as the El Niño decays.  The weekly data are impacted by “weather noise” so we should expect to see another couple of upticks from time to time, but the 2015/16 El Niño is decaying on schedule.  El Niños are tied to the seasonal cycle and typically peak in November to January. See the post here.

02 NINO Region Evolutions

Figure 2

THE MULTIVARIATE ENSO INDEX

The Multivariate ENSO Index (MEI) is another ENSO index published by NOAA.  It was created and is maintained by NOAA’s Klaus Wolter.  The Multivariate ENSO Index uses the sea surface temperatures of the NINO3 region of the equatorial Pacific, along with a plethora of atmospheric variables…thus “multivariate”.

According to the most recent Multivariate ENSO Index update discussion, the El Niño conditions are decaying and “dropping below a Top-3 ranking”:

Compared to last month, the updated (February-March) MEI has decreased further (by 0.16) to +1.96, dropping below a Top-3 ranking for the first time since April-May 2015. This nine-month run in the Top-3 is tied with 1982-83 for its duration, while 1997-98 kept this level going for a full 12 months. No other El Niño since 1950 even exceeded three months at that level. The August-September 2015 value of +2.53 represents the peak of the 2015-16 event, and was exceeded only during the 1982-83 and 1997-98 events. The overall evolution of the 2015-16 El Niño has been most similar to both 1965-66 and 1997-98, as monitored by the MEI.

There’s something else to consider about the MEI.  El Niño and La Niña rankings according to the MEI aren’t based on fixed threshold values such as +0.5 for El Niño and -0.5 for La Niña.  The MEI El Niño and La Niña rankings are based on percentiles, top 30% for the weak to strong El Niños and the bottom 30% for the weak to strong La Niñas.   This is difficult to track, because, when using the percentile method, the thresholds of El Niño and La Niña conditions vary from one bimonthly period to the next, and they can change from year to year.

The Multivariate ENSO Index update discussion and data for January/March were posted on April 6th.  Figure 3 presents a graph of the MEI time series starting in Dec/Jan 1979.  And Figure 4 compares the evolution in 2015/16 to the reference El Niños of 1982/83 and 1997/98.

03 MEI Time Series

Figure 3

# # #

04 MEI Evolution

Figure 4

According to NOAA’s Multivariate ENSO Index, the 2015/16 El Niño was weaker than the 1982/83 and 1997/98 events.

EL NIÑO EVOLUTION COMPARISONS WITH TAO PROJECT SUBSURFACE DATA

IMPORTANT NOTE:  The 1982 values of the TAO Project subsurface data have to be taken with a grain of salt. The deployment of the TOA project buoys started in the late 1980s and was not compete until the early 1990s.  Also keep in mind that these values are the output of a reanalysis (a computer model), not observations-only-based data. [End note.]

The NOAA Tropical Atmosphere-Ocean (TAO) Project website includes the outputs of a reanalysis for two temperature-related datasets for the waters below the surface of the equatorial Pacific.  See their Upper Ocean Heat Content and ENSO (new) webpage for descriptions of the datasets and for a link to the data presented in the following graphs.   The two datasets are Warm Water Volume (above the 20 deg C isotherm) and the Depth-Averaged Temperatures for the top 300 meters (aka T300).  Both are available for the:

  • Western Equatorial Pacific (5S-5N, 120E-155W)
  • Eastern Equatorial Pacific (5S-5N, 155W-80W)
  • Total Equatorial Pacific (5S-5N, 120E-80W)

Keep in mind that the longitudes of 120E-80W stretch 160 deg, almost halfway around the globe. For a reminder of width of the equatorial Pacific, see the protractor-based illustration here. Notice also that the eastern and western data are divided at 155W, which means the “western” data extend quite a ways past the dateline into the eastern equatorial Pacific.

Note:  The TAO Project website recently modified their reporting of these datasets.  In the past, they included what appeared to be month-to-date values for the current month. With the new reporting, they have eliminated the values for the current month. [End note.]

In the following three illustrations, we’re comparing reanalysis outputs for the evolution of the 2015/16 El Niño so far (through March 2016) with the outputs for the evolutions of the 1982/83 and 1997/98 El Niños. The Warm Water Volume outputs are the top graphs and the depth-averaged temperature outputs are the bottom graphs.  As you’ll see, the curves of two datasets are similar, but not necessarily the same.

Let’s start with the Western Equatorial Pacific (5S-5N, 120E-155W), Figure 5. The warm water volume and depth-averaged temperature anomalies show the Western Equatorial Pacific began 2015 with noticeably less warm water than during the opening months of 1997.  The western equatorial Pacific supplies the warm water for an El Niño.  Claims that El Niños are becoming stronger due to human-induced global warming are obviously not supported by the subsurface data from the western equatorial Pacific.  The warm water volume in 1982 was comparable at the start of this year but depth-averaged temperature anomalies started off higher in 2015 than in 1982. Notice how there was a much greater decline in 1997/98 than 2015/16.  That indicates more warm water migrated eastward from the western tropical Pacific during the 1997/98 event than in 2015/16….another indication that the 2015/16 El Niño was weaker that the one in 1997/98.

05 WWV and T300 Evolutions - West

Figure 5

Both warm water volume and depth-averaged temperature anomalies in the Eastern equatorial Pacific (5S-5N, 155W-80W) in 2015/16 had lagged behind the values of 1997/98, but had been greater than the 1982/83 values for most of the event.  See Figure 6.  Both the warm water volume and T300 have recently fallen into line with those seen in 1997/98 and are now lower than the values in 1982/83.

06 WWV and T300 Evolutions - East

Figure 6

Once again, with the noticeable differences between the 1997/98 and 2015/16 events, data contradict claims that the 2015/16 El Niño was stronger that the event of 1997/98.

The total of the TAO project eastern and western equatorial subsurface temperature-related reanalysis outputs, Figure 7, are as one would expect looking at the subsets. Both the warm water volume and the subsurface T300 data show greater drops in 1997/98 than in 2015/16, suggesting that more heat was released from equatorial Pacific in 1997/98 that in 2015/16.

07 WWV and T300 Evolutions - Total

Figure 7

SOUTHERN OSCILLATION INDEX (SOI)

The Southern Oscillation Index (SOI) from Australia’s Bureau of Meteorology is another widely used reference for the strength, frequency and duration of El Niño and La Niña events.  We discussed the Southern Oscillation Index in Part 8 of the 2014/15 El Niño series. It is derived from the sea level pressures of Tahiti and Darwin, Australia, and as such it reflects the wind patterns off the equator in the southern tropical Pacific.  With the Southern Oscillation Index, El Niño events are strong negative values and La Niñas are strong positive values, which is the reverse of what we see with sea surface temperature-based indices.  The March Southern Oscillation Index value is -4.7, which is a lesser negative value than the threshold of El Niño conditions. (The BOM threshold for El Niño conditions is an SOI value of -8.0.)  In other words, according to the SOI, we were in ENSO neutral conditions last month. Figure 8 presents a time-series graph of the SOI data.  The BOM SOI data provide more indications that the 2015/16 event was comparable to or weaker than many El Niño events.

08 SOI Time Series

Figure 8

Note that the horizontal red line is the present monthly value, not a trend line.

The graphs in Figure 9 compare the evolution of the SOI values in 2015/16 to those in 1982/83 and 1997/98. The top graph shows the raw data. Because the SOI data are so volatile, I’ve smoothed them with 3-month filters in the bottom graph. Referring to the smoothed data, the Southern Oscillation Index has recently once again fallen behind the values in 1997 and is still lagging behind the values in 1982.

09 SOI Evolution

Figure 9

Also see the BOM Recent (preliminary) Southern Oscillation Index (SOI) values webpage. The current 30-day running average and the 90-day average are still in El Niño conditions.

COMPARISONS OF HOVMOLLER DIAGRAMS OF THIS EL NIÑO (TO DATE) WITH 1982/83 AND 1997/98

NOTE:  The NOAA GODAS website has not yet added 2016 to their drop-down menu for Hovmoller diagrams. For the following illustrations, I’ve extended the Hovmoller diagrams by splicing the 2016 portions of the most recent ones onto 2015 so that we can compare the evolutions and decays of the El Niños. [End note.]

Hovmoller diagrams are a great way to display data.  If they’re new to you, there’s no reason to be intimidated by them. Let’s take a look at Figure 10.  It presents the Hovmoller diagrams of thermocline depth anomalies (the depth of the isotherm at 20 deg C.  Water warmer than 20 deg C is above the 20 deg C isotherm and below it the water is cooler). 2015 is in the center, 1997 on the left and 1982 to the right.  (Sorry about the different sizes of the Hovmollers, but somewhere along the line NOAA GODAS changed them, but they are scaled, color-coded, the same.)

The vertical (y) axis in all the Hovmollers shown in this post is time with the Januarys at the top and Decembers at the bottom.  The horizontal (x) axis is longitude, so, moving from left to right in each of the three Hovmoller diagrams, we’re going from west to east…with the Indian Ocean in the left-hand portion, the Pacific in the center and the Atlantic in the right-hand portion.  We’re interested in the Pacific. The data are color-coded according to the scales below the Hovmollers.

Figure 10

Figure 10

Figure 10 is presenting the depth of the 20 deg C isotherm along a band from 2S to 2N. The positive anomalies, working their way eastward early in 1982, 1997 and 2015, were caused by downwelling Kelvin waves, which push down on the thermocline (the 20 deg C isotherm).  You’ll note how the anomalies grew in strength as the Kelvin wave migrated east. That does not mean the Kelvin wave is getting stronger as it traveled east; that simply indicates that the thermocline is normally closer to the surface in the eastern equatorial Pacific than it is in the western portion.  In this illustration, we’re looking at anomalies, not absolute values.

Based on thermocline depth anomalies, the El Niño conditions were much stronger in 1997 than they were in 1982 and in 2015.

Figure 11 presents the Hovmollers for wind stress (not anomalies) along the equator.   The simplest way to explain them is that they’re presenting the impacts of the strengths and directions of the trade winds on the surfaces of the equatorial oceans. In this presentation, the effects of the east to west trade winds at various strengths are shown in blues, and the reversals of the trade winds into westerlies are shown in yellows, oranges and reds.  To explain the color coding, the trade winds normally blow from east to west; thus the cooler colors for stronger east to west trade winds. The reversals of the trade winds (the yellows, oranges and reds) are the unusual events and they’re associated with El Niños, which are the abnormal state of the tropical Pacific.  (A La Niña is simply an exaggerated normal state.)

Figure 11

Figure 11

The two westerly wind bursts shown in red in the western equatorial Pacific in 1997 are associated with the strong downwelling Kelvin wave that formed at the time. (See the post ENSO Basics: Westerly Wind Bursts Initiate an El Niño.) Same thing with the three westerly wind bursts early in 2015, January through April:  they initiated the Kelvin wave this year. Throughout 1997, there was a series of westerly wind bursts in the western equatorial Pacific. Same thing occurred in 2015. There were comparatively few westerly wind bursts early in 1982, and the bursts early in 1982 appear to have been weaker than those in 1997 and 2015, according to this GODAS reanalysis. But there was a strong westerly wind burst later in 1982.  Returning to 2015/16, the most recent westerly wind burst happened in January 2016.

Figure 12 presents the Hovmollers of wind stress anomalies…just a different perspective.  But positive wind stress anomalies, at the low end of the color-coded scale, are actually a weakening of the trade winds, not necessarily a reversal.

Figure 12

Figure 12

NOTE: There are a number of wind stress-related images on meteorological websites.  Always check to see if they’re presenting absolute values or anomalies.  [End note.]

And Figure 13 presents the Hovmollers of sea surface temperature anomalies along the equator.

Figure 13

Figure 13

Notice the extremely high sea surface temperature anomalies in the eastern equatorial Pacific got during the peak of the 1997/98 El Niño. While the sea surface temperatures in 2015/16 have reached well above threshold of a strong El Niño, they’re still well behind those of the 1997/98 El Niño…especially east of 120W (to about 90W), where sea surface temperature anomalies were more than 4.0 deg C. In 1982/83, sea surface temperature anomalies also reached 4.0 deg C, but we never reached those values in 2015/16.

That is, as noted earlier, the 1997/98 was a stronger East Pacific El Niño than the 2015/16 event.

THE DOWNWELLING KELVIN WAVE HAS MADE ITS PRESENCE KNOWN ALONG THE EQUATORIAL PACIFIC

We normally focus our attention on the temperature of the waters below the equatorial Pacific when trying to determine what the upcoming ENSO season will bring. See Animation 1.  It shows the temperature anomalies of the waters to depth along the equator starting in January 2016.  The central portion shows the equatorial Pacific.  As illustrated, an upwelling (cool) Kelvin wave has migrated east along the Cromwell Current (a.k.a. Pacific Equatorial Undercurrent).  Those cooler-than-normal subsurface waters are being drawn to the surface, soon to replace the positive anomalies associated with the El Niño and soon to initiate a possible La Niña.

Animation 1

Animation 1

As noted earlier, there is not a lot of warmer-than-normal subsurface waters left below the equatorial Pacific.

But by focusing on the equator, we lose track of something very important, and it is the warm subsurface waters that are leftover from the El Niño…

THE SLOW MOVING ROSSBY WAVES NORTH AND SOUTH OF THE EQUATOR

In the March ENSO update, we discussed how the most recent Kevin wave (initiated by the January 2016 Westerly Wind Burst) appeared to split the pocket of subsurface warm waters in the eastern equatorial Pacific in February 2016, creating two pockets of warm subsurface waters…one north of the equator and another south of the equator.  Those two pockets of warm subsurface waters (leftovers from the El Niño) are now migrating westward very slowly…very slowly (as Rossby waves).  I’ve updated the animation of the temperature anomaly maps for the depths of 0-300 meters (a.k.a. T300) in Animation 2.

Animation 2

Animation 2

In the March update, we illustrated and discussed how it appeared that only one Rossby wave had formed north of the equator following the 1997/98 El Niño, which is why I focused on the pocket of warm water south of the equator in 2016.  Refer to the discussion in the March ENSO update for further information. We’ll discuss these phenomena in more detail in an upcoming post.

EL NIÑO REFERENCE POSTS

For additional introductory discussions of El Niño processes see:

Also see the entire 2014-15 El Niño series.  We discussed a wide-range of topics in those posts.

WANT TO LEARN MORE ABOUT EL NIÑO EVENTS AND THEIR AFTEREFFECTS?

My ebook Who Turned on the Heat? goes into a tremendous amount of detail to explain El Niño and La Niña processes and the long-term aftereffects of strong El Niño events.  Who Turned on the Heat? weighs in at a whopping 550+ pages, about 110,000+ words. It contains somewhere in the neighborhood of 380 color illustrations. In pdf form, it’s about 23MB. It includes links to more than a dozen animations, which allow the reader to view ENSO processes and the interactions between variables.

Last year, I lowered the price of Who Turned on the Heat? from U.S.$8.00 to U.S.$5.00.  And the book sold well.  It continues to do so this year.

A free preview in pdf format is here.  The preview includes the Table of Contents, the Introduction, the first half of section 1 (which was provided complete in the post here), a discussion of the cover, and the Closing. Take a run through the Table of Contents.  It is a very-detailed and well-illustrated book—using data from the real world, not models of a virtual world. Who Turned on the Heat? is only available in pdf format…and will only be available in that format.  Click here to purchase a copy.

My sincerest thanks to everyone who has purchased a copy of Who Turned on the Heat? as a result of the El Niño posts in 2014 and from this year’s El Nino series.

A NEW BOOK AND IT’S FREE

I also published On Global Warming and the Illusion of Control (25MB .pdf) back in November.  The introductory post is here.  It also includes detailed discussions of El Niño events and their aftereffects…though not as detailed as in Who Turned on the Heat?

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48 thoughts on “April 2016 ENSO Update – La Niña Alerts Issued for Later This Year and NINO1+2 SSTa Are Near Zero Deg C

  1. Ah! Natural cycles, the alarmists’ great heresy.
    Alarmist reaction in February 2016: “The hottest months evuh”, to their inevitable and highly predictable future comment of: “nothing to see here, let’s all move along” in just 12 months from now.

    • Agreed. The elephant in the room on climate is the variability due to other factors than CO2 warming, if that even exists to a measurable degree. The Little Ice Age, and the El Niño/La Niña cycles on a much more rapid time frame give the best-funded portion of climate studies all sorts of problems.

    • Or they might continue what they have done in the past and use data “corrections” that lower past temperatures and raise present temperatures to make it appear that global temperatures are still rising. Any cold temperatures you experience will be explained as “local weather.” And Mosher will come along to claim that the average temperature didn’t change. He knows full well that keeping the average the same is easy to do if you lower past temperatures and raise recent temperatures in equal proportions. Take three numbers: 6, 6,6. The average is 6. Now adjust them to 5, 6, 7. The average is still 6. Further adjustments to 4, 6, 8 doesn’t change the average value either. See how it works?
      If I remember correctly, the record temperatures of the 1998 El Niño were adjusted slightly lower to make 2010 the hottest year ever. And more recently, both NOAA and GISS have switched to NOAA’s overcooked “pause-busting” sea surface temperature data that lowers 1998 temperatures even more. So what’s to stop them from using these same tricks in the future? If people haven’t caught on to the scheme by now, they never will. Someone who believes that the “science is settled” but the temperature data upon which the science is based is never settled, can believe any contradiction.

      • As bob Tisdale will tell you.. the Entire SST record is WARMER before adjustments.
        “Take three numbers: 6, 6,6. The average is 6. Now adjust them to 5, 6, 7. The average is still 6. Further adjustments to 4, 6, 8 doesn’t change the average value either. See how it works?”
        Silly. That is WHY we talk about TRENDS…. look at the trends in your three silly cases.
        here is a clue.
        There was an LIA.
        The past was Colder than the present.
        If you look at only raw data, the past was STILL colder
        if you adjust the trend changes a small amount.
        The science remains EXACTLY the same whether you adjust or not.
        to WIT
        A) Regardless of how you adjust, C02 is STILL a GHG
        B) regardless of how you adjust, Man is still the cause of the increase in c02
        C) regardless of how you adjust, in 1896, the science said “IF you increase c02, the planet will warm.
        D) Regardless of of how you adjust, this prediction is Confirmed by the evidence.
        E) Regardless of how you adjust there are STILL natural cycles.
        F) regardless of how you adjust, natural cycles do not cause warming and cooling—- They are the EFFECT not the cause. to see this plot two series. In series A plot only the El Nino years. in series
        B plot only the La Nina years. tell me what you see,.
        The simple fact is the world is getting warmer. And the best explanation is that man plays a Part.
        perhaps a small part, perhaps a large part. but to understand that you have to do science.

    • “As bob Tisdale will tell you.. the Entire SST record is WARMER before adjustments.”
      And as every alarmist will tell you, it’s about the change in temperatures, not the temperature as such. Thus lowering the past by more than you increase the present may lower temperatures but it increases the change – the bit claimed to be caused by CO2.
      I cannot udnerstand why you try to defend this as if the effect is not in favour of the Alarmists?
      The actual temperatures do not matter, only the change, and it is the change that is being increased.

      • Tim Hammond
        “The actual temperatures do not matter, only the change, and it is the change that is being increased.”
        ——————–
        In fact the adjustments to pre 1945 sea surface temperatures tend to increase the raw temperatures. This raises the overall temperature but significantly reducing the long term trend. Bob Tisdale pointed this out in a recent previous post: https://bobtisdale.files.wordpress.com/2016/04/figure-12.png?w=720
        That’s the very opposite of what someone who was trying to make the warming trend warmer would do.

    • Gday mate. Seems like whenever someone steps our on the back porch and proclaims, “We could sure use some rain,” a monsoon often follows. Be careful what you wish for.

      • There is a big high pressure system centered over the Eastern U.S.right now, which is blocking the normal west-to-east flow of weather systems. The storm fronts are bumping up against the High and slowing down and dropping lots of rain on the same place.
        This is an El Nino year so I suppose it would be expected that a high pressure system would establish itself over the U.S. early this year. I don’t know if this particular high pressure system will move on out to the East or stay where it is, but eventually a high pressure system should sit down on the U.S., at least for a while.
        Anyone under a high pressure system will experience hot temperatures and dry conditions. How are you guys up East liking that nice warm weather recently? If that High were to sit there several more months, you wouldn’t like it so much. 🙂
        A High Pressure System should set up over the U.S. sometime later this year. That is the usual turn of events. But we did have some summers where that didn’t happen, and high pressure systems did not establish themselves for very long, and did not disturb the west to east flow very much.
        The focus of my weather curiosity when summer gets near is to look for a high pressure system, and see where it is going to set up, relative to me.
        The high pressure system over the East right now, for example, were it to remain there over the summer, would be a good sign for my area as it would mean that I am located on the western margin of the High, so storm fronts are still able to enter my area and give us cooler weather and mositure. Inside the high pressure system, you get none of that, as the High blocks the fronts from coming through.
        Whereas, if the High Pressure System sets up over the central U.S., than I am right in the middle of the hot zone, and the only question to ask then is how long is that High going to sit there before it moves.
        The center of the High Pressure System is always the hottest part. If you want to know where the center is on an unmarked weather map, just look for the highest temperature.

  2. Bob, thanks for the detailed update. Is there a reason we never see a Niño 1+2+3+4 trend? Why not look at the big picture as well?
    It certainly looks like the La Niña is already developing around the Galapagos Islands where sea surface temperature anomalies are now well below 0C.
    https://oz4caster.files.wordpress.com/2016/04/s5-um-cci-ssta-2016-04-18.gif
    It’s also interesting to see the large and intensifying cold anomalies in the northern Pacific and northern Atlantic. I’m not sure how unusual these might be.

  3. “This month we’re including the 1997/98 El Niño because it was the strongest El Niño in our short instrument temperature record.”
    I can’t completely agree with Bob Tisdale here, sofar he explicitly mentions the instrument records:
    – both HadCRUT4 and Berkeley Earth start their datasets with 1850;
    – there was a very strong El Niño event in 1877/78.
    On the first plot we can see the peak. Caution: all data is normalized wrt UAH’s baseline (1981-2010):
    http://fs5.directupload.net/images/160418/9wpxf8ig.jpg
    The second plot is a comparison of the 1877/78, 1997/98 ans 2015/16 Niños:
    http://fs5.directupload.net/images/160418/zt5p9x5g.jpg
    To obtain an accurate comparison, all three event windows (jan x – feb x+1) were overlaid by normalizing the anomalies wrt to their window as baseline (like Bob Tisdale did in a recent guest post, but over all 14 months instead of 3).
    We see the 1877-78 event in blue, with an OLS trend quite a bit higher than those of the recent guys.

    • A little hint: These are simplest plots using Excel (with euuropean customisation, hence commata mean dots).

    • Bindidon, the graphs you presented appear to be for global data. Yet in this post I’ve presented weekly sea surface temperature data for the NINO regions, and monthly data for the other equatorial Pacific datasets. The weekly NINO region data start in 1991 and many of the other datasets start in 1978.
      Source sea surface temperature data for the NINO regions are sparse before the 1950s, and they grow even more sparse before the opening of the Panama Canal in 1914. For that reason, I normally exclude the data before 1900 when looking at the long-term NINO region data. Also with the disparities between sea surface temperature datasets, we have no idea how strong ENSO events really were in the past. See the post “How Strong Was That El Niño or La Niña? – No One Knows For Sure”:
      https://bobtisdale.wordpress.com/2016/01/14/how-strong-was-that-el-nino-or-la-nina-no-one-knows-for-sure/
      Also, your last comparison doesn’t consider that there is very little source data globally in 1878, compared to the other years you’re referencing. For that reason, the monthly data in 1878 is likely more volatile than we might expect to see now.

  4. Bob, do we trust CFS.v2 after the exposure of the large errors that had to be corrected recently?

    • It seems that every time nature negates their forecasts/projections they then come up with a newly discovered error. How convenient. How does one trust anything they say?

    • Also, I had forecast this shift last year when they were still talking about an El Nino that should last for most of 2016. Once again the amateur beats the established consensus scientists.

    • ossqss, personally, I don’t pay attention to ENSO models, especially at this time of year with the (boreal) springtime prediction barrier.
      What might the future bring? There was a multiyear La Nina following the 1997/98 El Nino, but after the 1982/83 El Nino, sea surface temperature anomalies dipped into La Nina conditions but didn’t stay there long enough to register on NOAA’s Oceanic NINO Index.
      http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml

  5. First, thanks. Very informative.
    Second: A dull and pedagogical issue, I know.
    “… NOAA CFS.v2 is now forecasting a moderately strong La Niña.
    On another blog, a different writer used the phrase
    Powerfully Cold La Niña
    On the other hand, you write “All of that warm water released by the El Niño has to go somewhere. It doesn’t magically disappear.
    I responded (on the other blog) in the following manner:
    “It seems an El Niño exposes the atmosphere to warm water and thereby energy enters the system. La Niña exposes the atmosphere to cold water and there is a cessation of energy from that source. Pressure, winds, clouds, and precipitation, that is weather, respond.
    To me an analogy is driving an auto up a hill. Foot on gas pedal, up you go. Reduce pressure of foot on pedal and the movement slows. This leads to the thought that “powerful” is not a word that fits my notion of a La Niña. There will be serious changes in weather for some places when a very cold La Niña replaces a very warm El Niño. Some of the weather events will be locally powerful.”
    I will appreciate your take on this because I know you have said La Niña & El Niño are not opposites. Thanks, John.

    • John F. Hultquist, NOAA classifies ENSO events by strength. I’m simply using that as a reference for my statements. Also, I don’t believe your analogy with a gas pedal works for the strengths of ENSO events.

  6. Dropping like a rock and fellow Californians can count on ongoing popularity of xeriscaping.

  7. All of that warm water released by the El Niño has to go somewhere. It doesn’t magically disappear.
    Maybe not ‘magically’…but two thing happen to it;
    1) the east warm anomaly water gets cooled & diluted by the returning cool upwelling current as the easterly trade wind resume. Just like pouring cool water into a pot of warmer water – the water which was warmer is now cooler.
    2) the more westward warm water is still flowing to the west to mix in with the already warm pool to the west. You pour 85F water into a pot that already has 85F water…the temperature is 85F. It is just now seen as ‘normal’ & not ‘anomalous’.
    I’ve mentioned before that, at times, you have a tendency to focus ‘only’ on the anomaly data & ignore the actual temperatures. For example, around the Galapagos Islands, you can have a tendency of the waters cooling but if they are not cooling as quickly as would be expected, it would show as a ‘warm anomaly’ even though the actual temperature trend is downward.

  8. Bob Tisdale wrote: “All of that warm water released by the El Niño has to go somewhere. It doesn’t magically disappear”
    Bob – why can it not just cool through migration to higher latitudes?
    The published data suggest that there was a moderate, prolonged increase in measured global temperature after 98. Do you expect the same to occur after this 2015?
    I would have thought that a positive anomaly in SST in any one location could radiate out to space quite quickly. The elevated LST over latter months is a symptom of this energy flow, is it not?

    • Michael Carter says: ” Bob – why can it not just cool through migration to higher latitudes?”
      It does cool, but there’s more warm water than “normal” and it starts off warmer than normal.
      Michael Carter says: “The published data suggest that there was a moderate, prolonged increase in measured global temperature after 98. Do you expect the same to occur after this 2015?”
      Yup. And of course it changes the radiation imbalance globally.
      Michael Carter says: “I would have thought that a positive anomaly in SST in any one location could radiate out to space quite quickly.”
      You assumption is that the associated temperature increase is only at the surface of the oceans.
      Michael Carter says: :The elevated LST over latter months is a symptom of this energy flow, is it not?”
      Much of the increases in land surface temperatures are not caused by increased energy flow directly from the tropical Pacific. That was one of the messages from Trenberth et al. (2002):
      http://www.cgd.ucar.edu/cas/papers/2000JD000298.pdf
      Cheers.

  9. I’m under the impression that when el nino breaks up, the warm water moves north and south as well as westward (making a C shape of warm anomalies) and drives the PDO up. Does this make sense?
    (Residual heat that doesn’t make it into the troposphere in winter months contributes to warm surface waters in the north pacific (blob region).)

  10. So what happened to all that warm water? Well, much of it evaporated and turned into moisture. It rose upward as all warm air does. It rises up into the great natural heat exchange 5-10 miles in the sky where the moisture cools, forms cold droplets and falls back into the ocean which is a secondary mechanism of cooling the water. Eventually the water cools to where less and less moisture is evaporated into the air and there is less heat to rise so there is less and less cooling, less cold rain. Eventually with less storms and clouds over the ocean, the sun is able to shine more into the water to where it begins to warm again.

  11. Can someone explain what is happening with the ENSO meter on this site? It has been stuck at 1.25 for the last 3 weeks, but hasn’t tracked sideways, Has the battery gone flat?

    • Can someone explain what is happening with the ENSO meter on this site?

      If you click on the graph that shows 1.25, it will now show 1.07. Two days ago, it showed 1.15 for last week.

  12. All of that warm water released by the El Niño has to go somewhere. It doesn’t magically disappear.

    Well as ‘all of that warm water’ has been giving its heat to the atmosphere – that is why the weather changes and the air temperature rises – it can just disappear it is called cooling. If there are clear skies at night and wind and then low levels of high frequency light from the Sun during the day water could cool quite fast.
    Or is that too simplistic?

    • Mosher says “there was a LIA…”
      Yes there was, and before that the Medieval Warming Period, or Medieval Climate Optimum, as some would say. And if you accept, as some do, that CO2 lags temperature peaks by about 800 years, then we should be seeing an increase in CO2 about right now, in a remarkable coincidence with the recent rise in temperature. So does the cause drive the effect, or do we have an effect masquerading as a cause. If the data weren’t so screwed up, we might figure it out…
      I think we should name this current period the “Industrial Climate Optimum” and all go safely to bed.

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