Written by Sig Silber
Contrary to what you might be reading or hearing, the onset of La Nina is at least temporarily stalled. It is likely to develop but it does not appear to be in any rush to do so. NOAA has not yet officially declared that we are in ENSO Neutral, but we have ENSO Neutral Conditions.
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 has had significant impacts this winter but the impact on June is not likely to be very noticeable The MJO is not likely to have much of an impact for the month of May due to the time of the year and the lack of indication of the MJO cycle being strong at this time. But over the next few months, it might slow the development of the La Nina.
Notice the Northern Pacific is again more like a giant anticyclone with clockwise motion so that which gets sent west at low latitudes is to some extent returned to North America but at higher latitudes. That pattern was interrupted last week probably due to the demise of the El Nino and the impact of the MJO. We still do not see the rapid movement of storms at lower latitudes from east to west. Most of CONUS storms are originating from Asia without nearly as much support from storms related to the Equator although we see some of that occurring. The entire circulation has slowed down as one would expect this time of the year.
As I am looking at the above graphic Monday evening May 30, I see what had been an active dry line firing up over Texas and to the north into the Great Plains now moving to the east and still recognizable as a distinct weather feature and causing havoc some of which I report on in the El Nino News section of this report. It was not showing earlier today but now you seen another dry line flaring up. I think you can still see the tropical system impacting the East Coast. As we move into a Summer Pattern, the concept of a storm track west to east becomes less relevant and we focus more on south to north movements i.e. the Monsoon in the Southwest and Tropical Storms in the East and Gulf of Mexico. 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 24, 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 Week 3-4 Experimental Forecasts
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 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 May 19, 2016:
Here is the Early Outlook for June Temperatures issued on May 19, 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 May 19, 2016:
Here is the Early Outlook for June Precipitation Issued on May 19, 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 30, 2016.
6-10 DAY OUTLOOK FOR JUN 05 – 09 2016
RECENT ENSEMBLE MEAN SOLUTIONS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION OVER NORTH AMERICA DURING THE 6-10 DAY PERIOD. AN UNUSUALLY AMPLIFIED FLOW PATTERN IS FORECAST WITH TROUGHS OVER THE EASTERN CONUS, THE ALEUTIANS/GULF OF ALASKA, AND ALONG THE U.S. WEST COAST, AND A RIDGE OVER THE INTERIOR WESTERN CONUS WHICH EXTENDS NORTH/NORTHWESTWARD TO WESTERN CANADA AND EASTERN ALASKA. THE MOST RECENT HIGH RESOLUTION SOLUTIONS FROM THE GFS AND ECMWF ARE IN BASICALLY GOOD AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS ALTHOUGH THE HIGH RESOLUTION SOLUTIONS ARE A BIT MORE AMPLIFIED WITH THE OVERALL PATTERN, AND A BIT LESS PROGRESSIVE WITH THE TROUGH FORECAST OVER THE EASTERN CONUS. THE ENSEMBLE SPAGHETTI CHARTS GENERALLY INDICATE LOW TO MODERATE SPREAD OVER THE EASTERN CONUS, AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS AND EASTERN PACIFIC. TODAY’S 500-HPA BLENDED HEIGHT CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS OVER MOST OF THE EASTERN CONUS AND ALASKA, AND NEAR TO ABOVE NORMAL HEIGHTS OVER THE WESTERN CONUS. THE LARGEST POSITIVE HEIGHT ANOMALIES ARE ANTICIPATED OVER THE NORTHERN ROCKIES, WHILE THE LARGEST NEGATIVE HEIGHT ANOMALIES ARE FORECAST OVER THE EASTERN GREAT LAKES AND EASTERN PACIFIC.
ANOMALOUS SOUTHWESTERLY FLOW ENHANCES PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF FLORIDA AND COASTAL SECTIONS OF THE MID-ATLANTIC AND SOUTHEAST. BELOW NORMAL HEIGHTS AND ANOMALOUS NORTHERLY FLOW FAVOR BELOW NORMAL TEMPERATURES FOR THE CENTRAL, NORTHEASTERN, AND INTERIOR EASTERN PORTIONS OF THE CONUS. ABOVE NORMAL HEIGHTS TILT THE ODDS TO ABOVE NORMAL TEMPERATURES FROM THE WEST COAST OF THE CONUS TO THE HIGH PLAINS. ABOVE NORMAL SEA SURFACE TEMPERATURES, ANOMALOUS SOUTHERLY FLOW, AND PERSISTENCE ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR ALASKA.
THE TROUGH EXPECTED OVER THE EASTERN CONUS FAVORS ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE EASTERN THIRD OF THE CONUS AND ALONG THE GULF COAST. ABOVE NORMAL HEIGHTS AND ANOMALOUS NORTHERLY FLOW TILT THE ODDS TO NEAR TO BELOW MEDIAN PRECIPITATION FOR MUCH OF THE CENTRAL CONUS. THE TROUGH NEAR THE WEST COAST FAVORS ABOVE MEDIAN PRECIPITATION FOR PARTS OF NORTHERN CALIFORNIA, THE PACIFIC NORTHWEST, THE CENTRAL GREAT BASIN, AND PARTS OF THE SOUTHWEST, SOUTHERN ROCKIES, AND SOUTHERN HIGH PLAINS. THE TROUGH OVER THE GULF OF ALASKA FAVORS ABOVE MEDIAN PRECIPITATION FOR MUCH OF SOUTHERN ALASKA AND THE ALASKA PANHANDLE, WHILE ANOMALOUS NORTHERLY FLOW LEADS TO ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTHWESTERN ALASKA.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODELS AND FORECAST TOOLS.
8-14 DAY OUTLOOK FOR JUN 07 – 13 2016
FOR WEEK-2, THE ENSEMBLE MEAN SOLUTIONS INDICATE LITTLE OVERALL CHANGE TO THE CIRCULATION PATTERN FROM THAT EXPECTED DURING THE 6-10 DAY PATTERN, ALTHOUGH THE WESTERN RIDGE IS FORECAST TO DEAMPLIFY WHILE THE EASTERN TROUGH IS FORECAST TO PROGRESS SLOWLY EASTWARD. THE ENSEMBLE SPAGHETTI CHARTS CONTINUE TO INDICATE LOW TO MODERATE SPREAD OVER THE EASTERN CONUS AND MODERATE TO LARGE SPREAD OVER THE WESTERN CONUS AND EASTERN PACIFIC. THE BLENDED 500-HPA HEIGHT CHART INDICATES BELOW NORMAL HEIGHTS OVER THE EASTERN HALF OF THE CONUS AND THE ALEUTIANS, WHILE ABOVE NORMAL HEIGHTS ARE EXPECTED OVER THE WESTERN HALF OF THE CONUS AND ALASKA.
THE TEMPERATURE PATTERN EXPECTED FOR WEEK-2 IS QUITE SIMILAR TO THAT FORECAST FOR THE 6-10 DAY PERIOD. THE TROUGH PREDICTED OVER THE GULF OF ALASKA ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR SOUTHERN ALASKA AND THE NORTHWESTERN CONUS. ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS NORTH/NORTHWESTERLY FLOW TILT THE ODDS TO BELOW MEDIAN PRECIPITATION FOR THE CENTRAL CONUS AND PARTS OF THE INTERIOR SOUTHEAST. THE TROUGH OVER THE NORTHEAST CONUS FAVORS ABOVE MEDIAN PRECIPITATION FOR THE NORTHEAST WHILE ANOMALOUS SOUTHWESTERLY FLOW ENHANCES PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR CENTRAL AND SOUTHERN FLORIDA. ABOVE NORMAL HEIGHTS TILT THE ODDS TO BELOW MEDIAN PRECIPITATION FOR PARTS OF NORTHERN ALASKA.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODEL SOLUTIONS, BUT OFFSET BY UNCERTAINTY IN THE DETAILS OF THE TOOLS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JUNE 16
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 the Outlook.
Now let us take a detailed look at the “Analogs” which NOAA provides related to the Outlook.
I prefer the set of analogs that relates 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. But the NOAA system for generating those pre-forecast analogs is not working. They publish a second set of analogs which relates the 6 – 10 Day Outlook to previous occurrences of that weather pattern and similarly for the 8 -14 Day Outlook. So that is what I am using today. It is explained here and here. I do not like my work being doubled so I decided to just use the second set of analogs which corresponds to Day 11 of the Outlook. In my mind that set of analogs tells you nothing (zilch) about the reliability of the forecasts but is helpful in predicting the outlook for the subsequent time periods. That is interesting also. I am also presenting them today in the order that they are provided which means the ones at the top have the highest level of correlation with the forecast and thus are more reliable for forecasting future time periods.
Day | ENSO Phase | PDO | AMO | Other Comments |
May 28, 1978 | Neutral | + | – | |
May 29, 1978 | Neutral | + | – | |
May 21, 1991 | El Nino | – | – | Strong Modoki |
May 22, 1991 | El Nino | – | – | Strong Modoki |
May 20, 1992 | El Nino | + | – | Strong Modoki |
May 31, 1996 | Neutral | + | – | Right after a La Nina |
June 1, 1996 | Neutral | + | – | Right after a La Nina |
May 15, 1999 | La Nina | – | + | Long Strong La Nina |
May 16, 1999 | La Nina | – | + | Long Strong La Nina |
One thing that jumped out at me right away was the spread among the analogs from May 15 to June 1 which is just over two weeks. That can be a sign that current conditions (as represented in the historical analogs) are fairly consistent for this time of the year. I have not examined the centroid of this distribution carefully like I did last week but it looks about right i.e. an unscientific analysis yields perhaps May 23 which is seven days before May 30 and these are analogs centered on 3 days and 4 days ago (May 26 or May 27) so things seem to be in sync pretty well.
There are this time three El Nino Analogs, four ENSO Neutral Analogs and two 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 strongly suggestive of McCabe condition A. The Atlantic is clearly in control right now. It is hard for me to say that the overall set of analogs are consistent with the forecast. 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 (Perhaps the title should change and it probably will next week)
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 24 | 13.90 | -1.57 | -9.49 |
May 25 | -1.7 | -1.09 | -9.23 |
May 26 | +3.3 | -0.07 | -8.87 |
May 27 | +5.4 | 1.12 | -8.48 |
May 28 | +0.8 | 1.69 | -8.02 |
May 29 | -4.8 | 2.28 | -7.53 |
May 30 | -8.2 | 2.77 | -7.09 |
The 30-day average, which is the most widely used measure, as of May 30 is reported at +2.77 which is no longer associated with an El Nino (usually required to be more negative than -8.0 but some consider -6.0 or even -5.0 value good enough). It is now on the La Nina side of Neutral. The 90-day average barely remains in El Nino territory at -7.09. 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 no longer continues to be indicative of an El Nino Event in progress.
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.
Based on the trend here is what the Queensland Model might suggest for World Precipitation. I might be jumping the gun here as the SOI has not been rising for the full two months that would be associated with this forecast but it is the closest match to the choices they offer. The SOI has been rising for only one month at this point.
Queensland also publishes graphics on how the Walker Circulation is related to the SOI and they are very interesting.
Obviously they are mostly interested in the impact on Australia but the Walker Circulation is a worldwide process and the rightmost part of these graphics relate to North and South America.
Low-Level Wind Anomalies
Here are the low-level wind anomalies. We now see light easterly anomalies which are probably an indication of both a lack of MJO activity and the death of the El Nino.
And now the Outgoing Longwave Anomalies which tells us where convection has been taking place.
Kelvin Waves
I am discontinuing coverage of the Kelvin Waves until they become relevant again. 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.
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 now more useful as we shift our focus and begin tracking the progress of this new Cool Event.
It shows the thermocline between warm and cool water. The 25C Isotherm is now reaching the surface west of 120W; 24C at 120W, and the 23C Isotherm at about 90W. The 28C Isotherm has moved west to about 160W. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is now at about 150W. Clearly the area has moved west as one expects when an El Nino dies. But mostly the warm anomaly has simply vanished.
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
And here is the current version of the TAO/TRITON Graphic.
———————————————— | A | B | C | D | E | —————– |
The 3.5C through 1.5C anomalies are no longer visible in the ONI Measurement Areas. So the maximum anomalies have declined by two and one half degrees Centigrade. 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. 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 gone I believe. A little later in the article I will do my own calculation and report on the NOAA calculation.
Subareas of the Anomaly | Westward Extension | Eastward Extension | Degrees of Coverage | ||||
Today | May 23, 2016 | Today | May 2016 | Today | In Nino 3.4 | May 23, 2016 | |
These Rows Show the Extent of ENSO Neutral Impacts on the Equator* | |||||||
0.5C or cooler** Anomaly | 175W | 155E | Land | 155W | 80 | 50 | 50 |
0C or cooler Anomaly | 155W | 155W | 110W | Land | 45 | 35 | 60 |
These Rows Show the Extent of the La Nina Impacts on the Equator* | |||||||
-0.5C or cooler Anomaly | 145W | 145W | 115W | Land | 30 | 25 | 55 |
-1C or cooler Anomaly | 138W | 140W | 122W | 105W | 16 | 16 | 35 |
-1.5C or cooler Anomaly | Land | 135W | Land | 120W | 0 | 0 | 15 |
* The temperatures are not yet clearly marked. I am assuming the isotherms are separated by 0.5C not 1C. There is a color code and I can not correlate it. So my divisions for these two categories could be off by 100% ie. where I say –1.5C that could be -3C but I do not think so and this week I am increasingly confident that I am interpreting the TAO/TRITON graphic correctly.
** Actually the temperature inside of an isotherm could be warmer or cooler than the isotherm. But during an El Nino it is likely that the temperature will be warmer and during a negative phase of ENSO it is likely to be cooler. What I attempt to do is measure the extent of warm water along the Equator during the positive phase of ENSO and the extent of cool water along the Equator during the negative phase of El Nino. The Neutral Phase presents a challenge. That is why you see larger extents for the warmer isotherms as I am attempting to show the extent of different levels of cooler water. I could reverse the calculation approach and show the increasing extent of less-cool water but that would be meaningless. If one was looking at grade-point averages in education, one could report the number of failed students in different groups closer to passing or further from passing. How you chose to do this would depend on what you wanted to know. In this case, I am trying to show how much water along the Equator is contributing to moving into a La Nina Condition. Alternatively, I could be reporting how much water along the Equator has to cool down in order to achieve La Nina Conditions. It is somewhat like reporting the probability of having a La Nina versus the probability of not having a La Nina. Given that the ENSO Measurement Area is 50 degrees Longitude, for the column labeled “in Nino 3.4” one could subtract that number from 50 and obtain the alternative way of interpreting the data.
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 30, in the afternoon working from the May 29 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | +0.6 | +0.7 |
B. 160W to 150W | +0.4 | +0.5 |
C. 150W to 140W | +0.0 | +0.0 |
D. 140W to 130W | -0.2 | -0.4 |
E. 130W to 120W | -0.6 | -0.6 |
Total | -0.0 | +0.2 |
Total divided by five subregions i.e. the ONI | (+0.2)/5 = 0 | (+0.2)/5 = 0 |
My estimate of the daily Nino 3.4 ONI remains at 0. NOAA has reported the weekly ONI to be -0.1 which is an ENSO Neutral value but ever so slightly on the La Nina side of the scale. Nino 4.0 is being again reported at 0.6 raising questions about if and how fast the Warm Pool is migrating to the West as it dissipates. Nino 3.0 is being reported a bit lower at -0.3. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is being reported as again being +0.2. Notice that Nino 1+2 had gone fairly negative for a short period of time but then bounced back. This La Nina is not coming on like gangbusters. WELCOME TO ENSO NEUTRAL. 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. The same data in graphical form but going back a couple of more years can be found here.
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.
Although I did not discuss the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures which remains relevant.
You can now see that the El Nino is totally gone. The cool water is reaching the surface a bit more but only extends to 140W which is 40% of the ONI measurement area so it remains ENSO Neutral. There is a bit of a gap around the Galapagos Islands. On the right you see every second week of this graphic historically so you can follow the progression.
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.
We have been showing 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.
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.
And here is the graphic from last week which added a week and removed the seven earliest days so it is a 30 day analysis through May 14, 2016
And here are the latest 30 Day Temperature and Precipitation Departure (same as anomalies) graphic one ending May 21 and then the latest ending May 28, 2016.
But looking at a longer time period in this 90 days or approximately three months.
El Nino in the News
We reported on this Dry Line last week.
We reported on the tropical potential in the vicinity of Cuba last week.
Attribution is difficult but I am categorizing this entire situation in Texas to El Nino. El Nino is dead but there is a lag (probably about two months) between the ONI showing a change in ENSO phase and the end of impacts.
Global Warming in the News
Trees produce aerosols that impact precipitation. I assume they are talking about more than just pollen
Sea Level Rise has a cyclical component This is from a blogger on “Watts Up With That?” and there is an interesting graphic that was posted. It is an update of a prior graphic from an earlier article. Asbury H. Sallenger Jr, Kara S. Doran & Peter A. Howd, Hotspot of accelerated sea-level rise on the Atlantic coast of North America, Nature Climate Change 2, 884–888 (2012), doi:10.1038/nclimate1597
I am not particularly interested in the debate over how people manipulate data by where they start and where they finish (that is common knowledge) nor in the slope of this curve which I do not understand but which looks like a sea level rise of less than half a meter per century (there is a similar graphic presented for Lower Manhattan) but I am interested in what appears to be a correlation with the ENSO cycle. Take a look at 72/73, 82/83, 97/98 etc. You get more sea ice melt in El Nino years and less in La Nina years.
Putting it all Together.
This El Nino has just this week ended in terms of current satisfying the criteria. It is possible that officially it may not be declared dead until the end of June because the Mar – Apr – May value of the ONI will clearly satisfy the 0.5 cutoff and it is possible that the Apr – May – Jun average ONI may still meet the criteria even though the daily not longer meets the criteria.
We are beginning to speculate on the winter of 2016/2017 which now according to most of the models seems likely to be a La Nina or Neutral with a La Nina bias.
The below is the CPC/IRI forecast issued on May 12, 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.
And one week later we have the second report recognizing that last week was based on a survey and this week is based on model means.
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 now have the May 1 Run of the JAMSTEC Model.
It is forecasting a moderate La Nina for next winter and continuing as a La Nina or Neutral with a La Nina tendency for the subsequent winter. That could be the signal for the Pacific Climate Shift.
Here is a repeat of the Australian Model for comparison purposes. It has not been updated since last week but will be updated next week.
It does not extrapolate as far into the future as the JAMSTEC model. It is somewhat similar to the NOAA model but seems to be less certain that we will have a La Nina rather then ENSO Neutral with a La Nina tendency.
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