Written by Sig Silber
ENSO is a persistent but irregular cycle caused by the rotation of the Earth which due to friction creates Easterly winds on the Equator which skim off the surface warm water and drive it to the Western Pacific. That creates what is labeled La Nina. On occasion, the process reverses and the accumulated warm water is able to move east to South America and that creates what is labeled El Nino. There is no doubt that this El Nino is waning and the pendulum is swinging in the other direction. What is not clear is how fast the pendulum will swing and will next winter be a La Nina or ENSO Neutral winter and if it is La Nina, how strong it will be. We discuss this and will be discussing and tracking this until we know the answer.
This is the Regular Edition of my weekly Weather and Climate Update Report. Additional information can be found here on Page II of the Global Economic Intersection Weather and Climate Report.
Let’s Now Focus on the Current (Right Now to 5 Days Out) Weather Situation.
A more complete version of this report with daily forecasts is available in Part II. This is a summary of that more extensive report. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks will take you directly to that set of information but it may take a few seconds for your browser to go through the two-step process of getting to Page II and then moving to the Section within Page II that is specified by this link.
Many graphics in this report are auto-updated by the source of the graphic. It is always my choice as the writer to allow these graphics to auto-update or “freeze them” to what they looked like when I write the article. Generally speaking graphics in research themes which appear above this point do not auto-update as they come from published scientific papers. When I make the decision to allow certain graphics to auto-update, it creates two issues: A. As the graphic updates, my commentary becomes out of sync with the new version of the graphic. This can be very extreme if for example you take a look at my report from months ago. B. On rare occasions, source sites for graphics go down and the graphic does not appear in the article and you probably see white space. If you experience such an event and that graphic is important to your understanding of the report, please return later to view my weather and climate column. Sometimes the “outage” is only for several minutes, but often the duration can be a number of hours or even one or more days. We feel that this inconvenience is preferable to looking at “frozen” weather map images that do not update since I write the article on Monday evenings and you probably do not read it until Tuesday and perhaps later in the week. So I want you to have the advantage of seeing the most up-to-date graphics. If the source is down, the white space is the price paid for most of the time being able to see the latest available graphics. |
First, here is a national animation of weather front and precipitation forecasts with four 6-hour projections of the conditions that will apply covering the next 24 hours and a second day of two 12-hour projections the second of which is the forecast for 48 hours out and to the extent it applies for 12 hours, this animation is intended to provide coverage out to 60 hours. Beyond 60 hours, additional maps are available at the link provided above.
The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color coding.
The map below is the mid-atmosphere 7-Day chart rather than the surface highs and lows and weather features. In some cases it provides a clearer less confusing picture as it shows only the major pressure gradients.This graphic auto-updates so when you look at it you will see NOAA’s latest thinking. The speed at which these troughs and ridges travel across the nation will determine the timing of weather impacts. This graphic auto-updates I think every six hours and it changes a lot.
The MJO is not likely to have much of an impact for the month of May as a whole as this MJO cycle appears to be weak and the forecasts of phase changes are contradictory. The MJO has had significant impacts this winter but the impact on May is not likely to be very noticeable.
Notice the Northern Pacific is like a giant anticyclone with clockwise motion so that which gets sent west due to El Nino is to some extent returned to North America but at higher latitudes. I am trying to see if I can discern a change in pattern towards lower latitudes for storms arriving from the Western Pacific but so far I do not see that in this animation.
As I am looking at the below graphic Monday evening May 9, I see a dry West and wet East pattern and the continued northerly displacement of the overall storm track. In the last few weeks the storm track has moved to the south slightly. But that seems to have ended for the time being. This graphic updates automatically so it most likely will look different by the time you look at it as the weather patterns are moving from west to east.
Below is an analysis of projected tropical hazards and benefits over an approximately two-week period. This graphic is scheduled to update on Tuesday and I am reading the May 3, 2016 Version and looking at Week 2 of that forecast.
Below is a graphic which highlights the forecasted surface Highs and the Lows re air pressure on Day 6 (the Day 3 forecast is available on Page II of this Report). This graphic also auto-updates.
Looking at the current activity of the Jet Stream
And here is the forecast out five days.
To see how the pattern is projected to evolve, please click here. In addition to the shaded areas which show an interpretation of the Jet Stream, one can also see the wind vectors (arrows) at the 300 Mb level.
This longer animation shows how the jet stream is crossing the Pacific and when it reaches the U.S. West Coast is going every which way.
Click here to gain access to a very flexible computer graphic. You can adjust what is being displayed by clicking on “earth” adjusting the parameters and then clicking again on “earth” to remove the menu. Right now it is set up to show the 500 hPa wind patterns which is the main way of looking at synoptic weather patterns.
And when we look at Sea Surface anomalies below, we see a lot of them not just along the Equator related to El Nino.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
6 – 14 Day Outlook Plus the 3 – 4 Week Experimental Forcast.
Now let us focus on the 6 – 14 Day Forecast for which I generally only show the 8 – 14 Day Maps. The 6 – 10 Day maps are always available in Part II of this report but in the Winter and Spring I often show both maps as the forecasted weather patterns change during that nine day period.
To put the forecasts which NOAA tends to call Outlooks into perspective, I am going to show the three-month MJJ Outlook and the recently updated Outlook for the single month of May and then discuss the 6 – 10 Day and the 8 – 14 Day Maps and the 6 – 14 Day NOAA Discussion within that framework.
First – Temperature
Here is the Three-Month MJJ Temperature Outlook issued on April 21, 2016:
Here is the Updated Outlook for May Temperatures issued on April 30, 2016.
Below are the current 6 – 10 Day and 8 – 14 Day Temperature Outlook Maps which will auto-update daily and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that as long as the patterns are moving from west to east fairly rapidly. I have also included the experimental Week 3 and 4 Outlook. The Week 3-4 Experimental Outlook updates weekly on Friday. Notice the Week 3-4 Experimental Outlook has fewer levels of probability starting with 50%.
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Looking further out.
Now – Precipitation
Here is the three-month MJJ Precipitation Outlook issued on April 21, 2016:
Updated Precipitation Outlook for May Issued on April 30, 2016
Below are the current 6 – 10 Day and 8 – 14 Day Precipitation Outlook Maps which will auto-update and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that as long as the patterns are moving from west to east fairly rapidly. I have also included the experimental Week 3 and 4 Outlook. The Week 3-4 Experimental Outlook updates weekly on Fridays. Notice the Week 3-4 Experimental Outlook has fewer levels of probability starting with 50%.
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook
Here are excerpts from the NOAA discussion released today May 9, 2016.
6-10 DAY OUTLOOK FOR MAY 15 – 19 2016
TODAY’S MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE OVERALL 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. AN ANOMALOUSLY STRONG TROUGH IS PREDICTED NEAR THE GREAT LAKES LEADING TO FORECAST BELOW NORMAL HEIGHTS FOR MUCH OF THE NORTH-CENTRAL AND NORTHEASTERN CONUS. RIDGING IS PREDICTED UPSTREAM OF THIS TROUGH OVER WESTERN CANADA AND PARTS OF THE NORTHWESTERN CONUS WHILE ABOVE NORMAL HEIGHTS ARE FORECAST FOR ALASKA. FARTHER TO THE SOUTH, A WEAK TROUGH IS PREDICTED OVER THE SOUTHWESTERN CONUS WHILE MOSTLY ZONAL FLOW IS FORECAST ACROSS THE SOUTHEASTERN CONUS. ENSEMBLE SPREAD IS HIGH TODAY OVER MUCH OF NORTHERN NORTH AMERICA (PARTICULARLY FOR ALASKA AND EASTERN CANADA) INDICATING LARGE UNCERTAINTIES AMONG INDIVIDUAL ENSEMBLE MEMBERS FOR THESE REGIONS. DUE, IN PART, TO THESE UNCERTAINTIES, TODAY’S OFFICIAL MANUAL HEIGHT BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS.
THE STRONG TROUGH PREDICTED NEAR THE GREAT LAKES LEADS TO ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES FOR MUCH OF THE NORTH-CENTRAL AND NORTHEASTERN CONUS. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE SOUTHEASTERN AND SOUTH-CENTRAL CONUS TO THE SOUTH OF A PREDICTED MEAN FRONTAL BOUNDARY. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR MOST OF ALASKA AND PARTS OF THE NORTHWESTERN CONUS UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS.
ABOVE MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF THE SOUTH-CENTRAL AND SOUTHEASTERN CONUS IN ASSOCIATION WITH A PREDICTED MEAN FRONTAL BOUNDARY. CONVERSELY, THERE ARE ENHANCED PROBABILITIES OF BELOW MEDIAN PRECIPITATION FROM THE WESTERN GREAT LAKES TO THE NORTHERN PLAINS DUE TO SUBSIDENCE BEHIND THE TROUGH FORECAST NEAR THE GREAT LAKES. ABOVE MEDIAN PRECIPITATION IS FAVORED AHEAD OF THE TROUGH AXIS FOR PARTS OF THE NORTHEASTERN CONUS. PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF ENSEMBLE MEMBERS ALSO SUPPORT ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE NORTHWESTERN CONUS. CONVERSELY, BELOW MEDIAN PRECIPITATION IS FAVORED FOR MUCH OF ALASKA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIRLY GOOD AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS OFFSET BY HIGH MODEL SPREAD AMONG THE COMPONENT ENSEMBLE MEMBERS OVER MUCH OF NORTHERN NORTH AMERICA.
8-14 DAY OUTLOOK FOR MAY 17 – 23 2016
TODAY’S ENSEMBLE MEAN SOLUTIONS AGREE IN FORECASTING A MEAN 500-HPA TROUGH NEAR THE WEST COAST OF THE CONUS AND MOSTLY ZONAL FLOW FOR MUCH OF THE EASTERN CONUS. ENSEMBLE SPREAD AND UNCERTAINTY ARE HIGH FOR ALASKA. THE GFS AND CANADIAN ENSEMBLE MEANS FORECAST A TROUGH NEAR THE ALEUTIANS AND A RIDGE OVER MUCH OF THE REMAINDER OF ALASKA. HOWEVER, THE ECMWF ENSEMBLE MEAN IS OUT OF PHASE AND FORECASTS A MEAN TROUGH OVER CENTRAL ALASKA. THE OFFICIAL WEEK TWO MANUAL HEIGHT BLEND REPRESENTS A COMPROMISE OF THE ENSEMBLE MEAN SOLUTIONS AND DEPICTS NEAR TO BELOW NORMAL HEIGHTS FOR THE NORTHEASTERN AND WESTERN CONUS AND NEAR TO ABOVE NORMAL HEIGHTS FOR THE SOUTHEASTERN CONUS AND ALASKA.
THERE ARE ENHANCED PROBABILITIES OF BELOW NORMAL TEMPERATURES FOR MUCH OF THE GREAT BASIN AND SOUTHWEST CONUS IN ASSOCIATION WITH A PREDICTED MEAN TROUGH AND NEGATIVE HEIGHT ANOMALIES. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF THE SOUTH-CENTRAL CONUS DUE TO ANTICIPATED MEAN SOUTHERLY LOW LEVEL FLOW. ABOVE NORMAL TEMPERATURES ARE ALSO FAVORED FOR THE SOUTHEASTERN CONUS DUE TO PREDICTED ABOVE NORMAL HEIGHTS. ENHANCED PROBABILITIES FOR BELOW NORMAL TEMPERATURES ARE INDICATED FOR MUCH OF THE NORTHEASTERN CONUS CONSISTENT WITH GEFS REFORECAST GUIDANCE AND WITH BIAS CORRECTED TEMPERATURES FROM THE 0Z ECMWF ENSEMBLE MEAN. CONVERSELY, ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF ALASKA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS.
THE TROUGH FORECAST NEAR THE WEST COAST LEADS TO ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE NORTHWESTERN CONUS. ABOVE MEDIAN PRECIPITATION IS ALSO FAVORED FOR MUCH OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY UNDERNEATH ANTICIPATED MEAN SOUTHERLY LOW LEVEL FLOW. PRECIPITATION ESTIMATES FROM THE GFS AND ECMWF ENSEMBLE MEMBERS ALSO SUPPORT ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE SOUTHEASTERN CONUS. CONVERSELY, THERE ARE ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR MUCH OF ALASKA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: BELOW AVERAGE, 2 OUT OF 5, DUE TO ONLY FAR AGREEMENT AMONG THE ENSEMBLE MEAN 500-HPA SOLUTIONS COMBINED WITH POOR AGREEMENT AGREEMENT AMONG THE TEMPERATURE TOOLS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON MAY 19
Some might find this analysis interesting as the organization which prepares it looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of this El Nino.
Analogs to Current Conditions
Now let us take a detailed look at the “Analogs” which NOAA provides related to the 5 day period centered on 3 days ago and the 7 day period centered on 4 days ago. “Analog” means that the weather pattern then resembles the recent weather pattern and was used in some way to predict the 6 – 14 day Outlook.
Here are today’s analogs in chronological order although this information is also available with the analog dates listed by the level of correlation. I find the chronological order easier for me to work with. There is a second set of analogs associated with the Outlook but I have not been analyzing this second set of information. The first set which is what I am using today applies to the 5 and 7 day observed pattern prior to today. The second set, which I am not using, relates to the correlation of the forecasted outlook 6 – 10 days out with similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. The second set of analogs may also be useful information but they put the first set of analogs in the discussion with the second set available by a link so I am assuming that the first set of analogs is the most meaningful and I find it so.
Centered Day | ENSO Phase | PDO | AMO | Other Comments |
May 15, 1952 | Neutral | – | + | |
May 16, 1952 | Neutral | – | + | |
Apr 25, 1971 | La Nina | – | – | |
May 4, 1971 | La Nina | – | – | |
May 19, 1985 | La Nina | + | – | |
May 4, 1990 | Neutral | + | – | |
May 6, 1992 | El Nino | – | – | El Nino Modoki Type II |
Apr 25, 1998 | El Nino | + | + | Tail End of Most Powerful Modern El Nino |
May 23, 2008 | La Nina | – | + |
One thing that jumped out at me right away was the spread among the analogs from Apr 25 to May 19 which is just a little more than three weeks. It suggests that the prior week conditions are highly correlated with weather patterns which in the past occurred over a fairly narrow range of dates as shown. There are this time two El Nino Analogs, three ENSO Neutral Analogs and four La Nina Analogs suggesting indecision or that we are now beyond the point where the Phase of ENSO is very important.
The phases of the ocean cycles in the analogs are inconclusive but slightly favor PDO Negative. This is somewhat negative for next winter if it is indicating the PDO will return to its Negative formation but it is a single data point. The seminal work on the impact of the PDO and AMO on U.S. climate can be found here. Water Planners might usefully pay attention to the low-frequency cycles such as the AMO and the PDO as the media tends to focus on the current and short-term forecasts to the exclusion of what we can reasonably anticipate over multi-decadal periods of time.
You may have to squint but the drought probabilities are shown on the map and also indicated by the color coding with shades of red indicating higher than 25% of the years are drought years (25% or less of average precipitation for that area) and shades of blue indicating less than 25% of the years are drought years. Thus drought is defined as the condition that occurs 25% of the time and this ties in nicely with each of the four pairs of two phases of the AMO and PDO.
Historical Anomaly Analysis
When I see the same dates showing up often I find it interesting to consult this list.
With respect to relating analog dates to ENSO Events, the following table might be useful. In most cases this table will allow the reader to draw appropriate conclusions from NOAA supplied analogs. If the analogs are not associated with an El Nino or La Nina they probably are not as easily interpreted. Remember, an analog is indicating a similarity to a weather pattern in the past. So if the analogs are not associated with a prior El Nino or prior La Nina the computer models are not likely to generate a forecast that is consistent with an El Nino or a La Nina.
El Ninos | La Ninas | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
Start | Finish | Max ONI | PDO | AMO | Start | Finish | Max ONI | PDO | AMO | |
DJF 1950 | J FM 1951 | -1.4 | – | N | ||||||
T | JJA 1951 | DJF 1952 | 0.9 | – | + | |||||
DJF 1953 | DJF 1954 | 0.8 | – | + | AMJ 1954 | AMJ 1956 | -1.6 | – | + | |
M | MAM 1957 | JJA 1958 | 1.7 | + | – | |||||
M | SON 1958 | JFM 1959 | 0.6 | + | – | |||||
M | JJA 1963 | JFM 1964 | 1.2 | – | – | AMJ 1964 | DJF 1965 | -0.8 | – | – |
M | MJJ 1965 | MAM 1966 | 1.8 | – | – | NDJ 1967 | MAM 1968 | -0.8 | – | – |
M | OND 1968 | MJJ 1969 | 1.0 | – | – | |||||
T | JAS 1969 | DJF 1970 | 0.8 | N | – | JJA 1970 | DJF 1972 | -1.3 | – | – |
T | AMJ 1972 | FMA 1973 | 2.0 | – | – | MJJ 1973 | JJA 1974 | -1.9 | – | – |
SON 1974 | FMA 1976 | -1.6 | – | – | ||||||
T | ASO 1976 | JFM 1977 | 0.8 | + | – | |||||
M | ASO 1977 | DJF 1978 | 0.8 | N | – | |||||
M | SON 1979 | JFM 1980 | 0.6 | + | – | |||||
T | MAM 1982 | MJJ 1983 | 2.1 | + | – | SON 1984 | MJJ 1985 | -1.1 | + | – |
M | ASO 1986 | JFM 1988 | 1.6 | + | – | AMJ 1988 | AMJ 1989 | -1.8 | – | – |
M | MJJ 1991 | JJA 1992 | 1.6 | + | – | |||||
M | SON 1994 | FMA 1995 | 1.0 | – | – | JAS 1995 | FMA 1996 | -1.0 | + | + |
T | AMJ 1997 | AMJ 1998 | 2.3 | + | + | JJA 1998 | FMA 2001 | -1.6 | – | + |
M | MJJ 2002 | JFM 2003 | 1.3 | + | N | |||||
M | JJA 2004 | MAM 2005 | 0.7 | + | + | |||||
T | ASO 2006 | DJF 2007 | 1.0 | – | + | JAS 2007 | MJJ 2008 | -1.4 | – | + |
M | JJA 2009 | MAM 2010 | 1.3 | N | + | JJA 2010 | MAM 2011 | -1.4 | + | + |
JAS 2011 | FMA 2012 | -0.9 | – | + | ||||||
T | MAM 2015 | NA | 1.0 | + | N |
Progress of the Warm Event
Let us start with the SOI.
Below is the Southern Oscillation Index (SOI) reported by Queensland, Australia. The first column is the tentative daily reading, the second is the 30 day moving/running average and the third is the 90 day moving/running average.
Date | Current Reading | 30-Day Average | 90 Day Average |
May 3 | -2.5 | -18.64 | -14.99 |
May 4 | -0.1 | -18.02 | -14.99 |
May 5 | +7.6 | -17.34 | -14.88 |
May 6 | +10.3 | -16.72 | -14.75 |
May 7 | +24.0 | -15.31 | -14.52 |
May 8 | +18.2 | -14.04 | -14.25 |
May 9 | +18.8 | -12.98 | -13.96 |
The 30-day average, which is the most widely used measure, as of May 9 is reported at -12.98 which is again clearly associated with an El Nino (usually required to be more negative than -8.0 but some consider -6.0 value good enough). It is quite a bit weaker (less negative) this week due to what might be the reversal of the SOI or it might still be changes in local conditions in Tahiti and Darwin Australia where the readings for this index originate. if there were two more weeks of such readings, the SOI would move into ENSO Neutral Territory. The 90-day average remains in El Nino territory at -13.96. Usually but not always the 90 day average changes more slowly than the 30 day average but it depends on what values drop out. The SOI continues to be indicative of an El Nino Event in progress but it is pretty much passed the time of year where it is very meaningful re El Nino development. I believe we will see a moderating trend in the SOI from here on with the possible exception of the continued local stormy conditions in Tahiti which for now have ended. But storms come and go so it may take longer than two weeks for the SOI to go NEUTRAL. It kind of looks like this is not very likely so it does seem the SOI is about to signal the end of this EL Nino just as the ONI is about to do the same.
The MJO or Madden Julian Oscillation is an important factor in regulating the SOI and Kelvin Waves and other tropical weather characteristics. More information on the MJO can be found here. Here is another good resource.
Low-Level Wind Anomalies
Here are the low-level wind anomalies. We see light westerly anomalies which are probably MJO related.
And now the Outgoing Longwave Anomalies which tells us where convection has been taking place.
Kelvin Waves
Let us now take a look at the progress of Kelvin Waves which are the key to the situation. From the earliest to the most recent they can be named #1 through #5. Kelvin Wave #1 has now been pushed off the top of this graphic as more recent information is added at the bottom.
One should keep in mind that for a new Kelvin Wave, the period of time from initiation to the termination of impacts is about six months. So when you have four or five this winter six in a row, the pattern of impacts on different indices and geographic areas becomes quite complex. It is further complicated as you can see above because the Kelvin Waves do not necessarily originate at the same location i.e. longitude.
We are now going to change the way we look at a three dimensional view of the Equator and move from the surface view to the view from the surface down. This El Nino appears to be fading slowly from west to east. The real decline will be from east to west.
Current Sub-Surface Conditions. Notice the lag in getting this information posted so the current situation may be a bit different than shown.
And now the pair of graphics that I regularly provide and which as I publish are currently able to be accessed from the NOAA website:
The above pair of graphics showing the current situation has an upper and lower graphic. The bottom graphic shows the absolute values, the upper graphic shows anomalies compared to what one might expect at this time of the year in the various areas both 130E to 90W Longitude and from the surface down to 450 meters.
The bottom half of the graphic (Absolute Values which highlights the Thermocline) perhaps is a now equally useful in terms of tracking the progress of this Warm Event as it converts to ENSO Neutral and then La Nina.
It shows the thermocline between warm and cool water. The 25C Isotherm is now reaching the surface. There is a lot of compression of the Isotherms so from 120W on east, the 20C is close to the surface and will reach the surface soon. We now pay close attention to the 28C Isotherm as west of that temperature is where convection is more easy to occur. The 28C Isotherm remains at about 140W or perhaps has shifted a bit further to the west. Thus we may remain in what is more like an El Nino Modoki situation for longer than most models predict. But the transition to ENSO Neutral is taking place pretty rapidly. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur.
Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.
TAO/TRITON GRAPHIC
Let us compare the situation as reported on October 4 to the most recent graphic. Remember each graphic has two parts the top part is the average values, the bottom part is those values expressed as an anomaly compared to the expected values for that date. Generally I am mainly discussing the bottom of the pairs of graphics namely the anomalies
First the October 4 version which I am providing for purposes of comparison. I “flash froze” the daily value that day so that it would not auto-update.
And then the December 14 version which I also “flash froze” to stop it from updating.
And then the current version of the TAO/TRITON Graphic.
———————————————— | A | B | C | D | E | —————– |
The 3.5C anomaly is no longer visible. Neither is the 3.0C anomaly or the 2.5C anomaly or the 2C anomaly. The 1.5C anomaly only exists in the Nino 3.4 Measurement Area south of the Equator and may soon be too far south to be counted. So the maximum anomalies (which do not appear everywhere) have declined by a full two and one half degrees Centigrade almost everywhere. This means that if one is attempting to mentally estimate the daily ONI, an approach would be to make an initial estimate of the midpoint of the 1C to 1.5C anomaly or 1.25C and subtract the reductions from there where the anomaly is less and add back in the area south of the Equator. What I have just described is not exactly the approach I use in my calculation below but it does provide a quick way to get a feel for the current strength of this El Nino. There is actually shading in the TAO/TRITON Graphic that might allow one to try to refine estimates a bit more than the contour lines but I rely on the contour lines. This El Nino is almost gone.
And an earlier but recent reference point close to the peak of this El Nino re the bottom half of the TAO/TRITON Graphic. You can certainly see the difference that three months makes.
The below table tracks the changes. It only addresses the situation right on the Equator so visually the TAO/TRITON graphic contains more information. But the below table turns visual information into quantitative information so it may be useful. The degrees of coverage shown in the rightmost two columns shows that the extent of the warm water directly on the Equator has been reduced in recent weeks. The way I constructed the table, the 1.0C anomaly as an example includes all water warmer than 1.0C so the 1.5C anomaly is included within it as well as the 2.0C anomaly which you can tell by the way I recorded the westward and eastward coordinates. I could have constructed this table in a different way. Note the 3C anomaly no longer exists. The 2.5C anomaly also no longer exists. As this El Nino decays I am including the less warm anomalies in the table below.
Subareas of the Anomaly | Westward Extension | Eastward Extension | Degrees of Coverage | |||||
Today | January 19, 2016 | Today | January 19, 2026 | Today | In Nino 3.4 | January 19, 2016 | ||
These Rows Show the Extent of El Nino Impacts on the Equator | ||||||||
3C or higher Anomaly | Gone | 158W | Gone | 134W | 0 | 0 | 24 | |
2.5C or higher Anomaly | Gone | 165W | Land | 110W | 0 | 0 | 55 | |
2.0C or higher Anomaly | Gone | 170W | Gone | 100W | 0 | 0 | 70 | |
1.5C or higher Anomaly | Gone | 175W | Gone | Land | 0 | 0 | 80 | |
1.0C or higher Anomaly | Gone | 175E | Gone | Land | 0 | 0 | 90 | |
0.5C or higher Anomaly | Inf | 160E | 138W | Land | Inf | 32 | 105 | |
These Rows Show the Extent of ENSO Neutral Impacts on the Equator | ||||||||
0.5C or less Anomaly | 138W | Land | Land | Land | 43 | 18 | 0 | |
0.0C or less Anomaly | 130W | Land | Land | Land | 35 | 10 | 0 | |
These Rows Show the Extent of the La Nina Impacts on the Equator | ||||||||
-0.5C or less Anomaly | 120W | Land | Land | Land | 25 | 0 | 0 | |
-1C or less Anomaly | 108W | Land | Land | Land | 13 | 0 | 0 |
I calculate the ONI each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W ONI measuring area into five subregions (which I have designated from west to east as A through E) with a location bar shown under the TAO/TRITON Graphic). I use a rough estimation approach to integrate what I see below and record that in the table I have constructed. Then I take the average of the anomalies I estimated for each of the five subregions. So as of Monday May 9, in the afternoon working from the May 8 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | 1.2 | 0.9 |
B. 160W to 150W | 1.5 | 1.1 |
C. 150W to 140W | 1.1 | 1.2 |
D. 140W to 130W | 0.8 | 1.0 |
E. 130W to 120W | 0.1 | 0.4 |
Total | 4.7 | 4.6 |
Total divided by five subregions i.e. the ONI | (4.7/5 = 0.9 | (4.6)/5 = 0.9 |
My estimate of the daily Nino 3.4 ONI after rounding remains this week at 0.9. NOAA has again reported the weekly ONI to be 0.8 which is the level of a weak El Nino but surprisingly not less than last week. The exact extent of the 1.5C+ anomaly south of the Equator has a big impact on the calculations. Nino 4.0 is being reported a bit lower at 0.8 raising questions about if and how fast the Warm Pool is migrating to the West as it dissipates. Nino 3.0 is being reported again at 0.4C . The action which I think is most important to track right now is in Nino 1+2. It have been a roller coaster up and down and now leveled off for the moment at+0.4C. The ONI is not measured in that area but it is significant. For the Coast of South America, the El Nino is over but we are not yet in a La Nina condition although the water directly off of Ecuador is now quite cold as can be seen in the TAO/TRITON graphic. I am only showing the currently issued version of the NINO SST Index Table as the prior values are shown in the small graphics on the right with this graphic.
ONI Recent History
The official reading for Feb/Mar/Apr is now reported as 1.6. I have discussed before the mystery of how the Nino 3.4 (ONI) CFSv2 values above get translated into the ERSST.v4 values shown below and if NOAA feels that working with two sets of books is a good way to operate, who am I argue. Many businesses do the same thing. As you can see this El Nino peaked in NDJ and is now declining and depending on what system you use it is either the 2nd or 3rd strongest El Nino since modern records were kept which is considered to be 1950. You could argue for it being #1 based on a week of readings but few are buying that argument. Still #2 or #3 means it is one of the strongest ever based on the way these events are measured. I will be writing more about that soon in a separate article. I believe the measurement system is inadequate re being useful in forecasting Worldwide weather impacts.
The full history of the ONI readings can be found here. The MEI index readings can be found here.
Is this El Nino a Modoki?
It did not evolve as a Modoki unless you consider it to be a continuation of the Faux El Nino Modoki of 2014/2015 which is a possible interpretation. But the Walker Circulation appears to be much like that of a Modoki. These graphics help explain this.
Although I discussed the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures.
Until recently watching this El Nino evolve has been like watching paint dry. But that was very different last week. This week it is difficult to see much change. The undercutting cool anomaly has totally replaced the warm pool off the coast of Ecuador. What remains is a weak El Nino that resembles a Modoki but may or not be a Modoki as discussed in elsewhere in this article. You can also see that there is not much left of the warm pool. It is not really moving back to the Western Pacific as one would expect. It is just disappearing. That may turn out to be very significant. IT MAY TAKE A LONG TIME FOR THE NEXT EL NINO TO BE GENERATED.
SST Surface Anomaly Hovmoeller
Here is another way of looking at it: Unlike the Upper Ocean Heat Anomaly Hovmoeller (I call it the Kelvin Wave Hovmoeller) which takes an average down to 300 meters, this just measures the surface temperature anomaly. It is the surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. A major advantage of the Hovmoeller method of displaying information is that it shows the history so I do not need to show a sequence of snap shots of the conditions at different points in time. Nevertheless this Hovmoeller provides a good way to visually see the evolution of this El Nino and later track its demise.
Recent Impacts of Weather Mostly El Nino but possibly Also PDO and AMO Impacts.
Below are snapshots of 30 Day temperature and precipitation departures over the life of this El Nino. The end date of the 30 day period is shown in the graphic. It is a way of seeing how the impacts of this El Nino have unfolded.
Remember this is a 30 day average and last week I used a different graphic so this can not be compared to last week but is best compared with last month. The La Nina pattern persists for much of the West with respect to both precipitation and temperature but is a normal El Nino for the Mississippi Valley in March. Northern California was wet but it is hard to say if that looks like El Nino or La Nina. This is one strange El Nino and for the 2nd or 3rd strongest in modern history it is a mystery that has not been given adequate attention.
Lets take a look at the combined results for the first three months of 2016: January, February and March.
And here is the April (30 day) graphic.
I realize this is a lot of graphics but one needs to look at the history of an event to assess it. As you can see, so far we are not having the expected El Nino Impacts in CONUS.
Here is the ninety day picture for February, March, and April.
And here is the latest graphic which adds a week and remove the seven earliest days so it is a 30 day analysis through May 7, 2016
View from Australia
El Nino
Below is the discussion just released. Notice the discussion re forecasting a La Nina for next winter.
El Niño drawing closer to an end
The tropical Pacific Ocean has weakened to borderline El Niño-neutral levels. Sea surface temperatures across the tropical Pacific Ocean cooled further in the past fortnight, driven by cooler than average waters below the surface. Atmospheric indicators are also trending towards normal. Trade winds have been consistently near normal for some weeks. Typical El Niño cloud patterns are dissipating and the Southern Oscillation Index (SOI), while still negative, is steadily rising.
All international models suggest the tropical Pacific Ocean will continue to cool, with seven of eight models exceeding La Niña thresholds by September 2016. However, individual model outlooks show a large spread between neutral and La Niña scenarios.
Based on recent changes in the tropical Pacific Ocean and atmosphere, combined with current climate model outlooks, the Bureau’s ENSO Outlook remains at La Niña WATCH. This means the likelihood of La Niña forming later in 2016 is around 50%.
Typically during La Niña, winter-spring rainfall is above average over northern, central and eastern Australia.
Very warm sea surface temperatures continue across large parts of the Indian Ocean. Likewise, ocean temperatures around Australia remain well above average. Warmth in these two regions may provide extra moisture for rain systems as they cross Australia during the coming months.
IOD (Indian Ocean Dipole)
The graphic comes with only a very short discussion and here is that discussion:
Indian Ocean Dipole outlooks
The Indian Ocean Dipole (IOD) is neutral. The weekly Dipole Mode Index value to 8 May is -0.01 °C.
Currently all international models monitored by the Bureau indicate negative IOD conditions are possible by July. However, model skill is generally lower at this time of year, and outlooks should be used with caution. Negative IOD events are more likely to occur during La Nina.
Information on the impact of a negative IOD on Australia can be found here.
El Nino in the News
2016 Weather Disasters (to date)
The Hot and Wet in India article might fit in this category. It is hard to separate out Global Warming from normal climate cycles unless you are a Climate Change Alarmist in which case it is all very clear to you or a CC Denier in which case it also is totally clear to you. Since I do not fit in either category I am left with the very difficult task of trying to sort it out. It is a bit like trying to sort out every medical condition from aging. We know that aging increases the odds of adverse medical conditions. But not all adverse medical conditions are attributable to age. This can become a problem what a doctor tells you are too young to have the symptoms you report or alternatively one dismisses certain symptoms as being simply age catching up with you when there is something not age related or only marginally age related going on. It is better to look at the evidence than start with a predetermined answer.
Global Warming in the News
The first article in the El Nino News Section could also fall in this category.
Putting it all Together.
This El Nino has peaked in intensity and is now in rapid decline. We are beginning to speculate on the winter of 2016/2017 which now according to most of the models seems increasingly likely to be a La Nina.
The below is the CPC/IRI forecast issued on April 21, 2016. It is important to remember that the first report in each month is based on a survey of meteorologists and the second report later in the month is based on the analysis of the forecast models. It is a minor difference but a difference. The first report in May should be available soon.
We have suggested that it is possible that some of the models and in particular NOAA’s model will be wrong about how fast the Eastern Pacific Warm Pool moves back towards its La Nina location and it may well be that next winter will be more of a Neutral year or even have some characteristics of an El Nino Modoki and thus be wetter than a typical year as the Warm Pool may still be more in the Central Pacific than shifted all the way west to its La Nina position.
I wish I had the May 1 Run of the JAMSTEC Model but here is the April 1 run and earlier you saw the Australian POAMA model run.
The JAMSTEC April 1 model run is definitely forecasting La Nina conditions for the heart of next winter but not very extreme and perhaps not with a duration that would have it qualify as an official La Nina.
Importance of the Strength of the La Nina
In many ways the ENSO Cycle has impacts like the PDO Cycle. So to some extent the intensity of a La Nina determines the impacts. That is why it is important to think about how intense this La Nina might be. Here is a graphic that shows the impacts of recent intense La Ninas on CONUS.
It is useful to look at the Phases of the PDO and AMO during these three months of each of these major La Ninas.
PDO | AMO | |
1988 – 1989 | – | – |
1998 – 1999 | – | + |
1999 – 2000 | – | – |
2007 – 2008 | – | + |
2010 – 2011 | – | + |
Forecasting Beyond Five Years.
So in terms of long-term forecasting, none of this is very difficult to figure out actually if you are looking at say a five-year or longer forecast. The research on Ocean Cycles is fairly conclusive and widely available to those who seek it out. I have provided a lot of information on this in prior weeks and all of that information is preserved in Part II of my report in the Section on Low Frequency Cycles 3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS. It includes decade by decade predictions through 2050. Predicting a particular year is far harder.
TABLE OF CONTENTS FOR PART II OF THIS REPORT The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page II where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.
A. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks (Usefully bookmarked as it provides automatically updated current weather conditions and forecasts at all times. It does not replace local forecasts but does provide U.S. national and regional forecasts and, with less detail, international forecasts)
B. Factors Impacting the Outlook
1. Very High Frequency (short-term) Cycles PNA, AO,NAO (but the AO and NAO may also have a low frequency component.)
2. Medium Frequency Cycles such as ENSO and IOD
3. Low Frequency Cycles such as PDO, AMO, IOBD, EATS.
C. Computer Models and Methodologies
D. Reserved for a Future Topic (Possibly Predictable Economic Impacts)
TABLE OF CONTENTS FOR PART III OF THIS REPORT – GLOBAL WARMING WHICH SOME CALL CLIMATE CHANGE. The links below may take you directly to the set of information that you have selected but in some Internet Browsers it may first take you to the top of Page III where there is a TABLE OF CONTENTS and take a few extra seconds to get you to the specific section selected. If you do not feel like waiting, you can click a second time within the TABLE OF CONTENTS to get to the specific part of the webpage that interests you.
D2. Climate Impacts of Global Warming
D3. Economic Impacts of Global Warming
D4. Reports from Around the World on Impacts of Global Warming