February 8, 2016, Weather and Climate Report – La Nina Conditions Persist

Written by Sig Silber

My editor has reminded me to be careful not make an incorrect implication.  To be sure, let me say it is NOT the fault of NOAA that the current El Nino is NOT acting like a typical El Nino.  (Capitals used to emphasize the double negative.)  I am not criticizing NOAA for this most powerful El Nino ever recorded behaving in many ways in CONUS much like a La Nina.  

I do think NOAA perhaps should have recognized this a bit sooner as I have but that is a minor complaint. Is this Climate Change or just a statistical aberration? Or is it just the way a slight westward displacement of an El Nino can impact the Walker Circulation and thus the positioning of the Aleutian Low, thereby creating a tendency for the Jet stream to be further north than one might otherwise anticipate?  And, furthermore,  March and April may return to a traditional El Nino pattern.

I am certain that NOAA also wants to better understand this and is working hard to do just that. All I try to do in my weekly weather column is report the information that is available to me. So far it has been an unusual winter and it appears that February will continue that pattern at least for the next week or possibly two. 

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. This link 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.

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. Right now it is showing for Day 7 a huge trough moving towards the East Coast. That would normally mean that one could decide what sort of weather one prefers and adjust their travel plans accordingly.  But as you will see when you read the discussion issued with today’s 6 – 14 Day Outlook it is not quite that simple right now.

Because “Thickness Lines” are shown by those green lines on this graphic it is a good place to define “Thickness”  and its uses. The thickness lines are now projected on Day 7 to be below 540 for CONUS only in the upper Northwest and Mountain States/Northern Plains Area. The 540 Level general signifies equal chances for snow at sea level locations. The level of storm activity in the Western Pacific had picked up when the MJO transitioned to its active phase but that then slowly shifted to its inactive phase. But the MJO may be shifting back to its active phase in about two weeks. Hopefully NOAA will take this into account in their next seasonal update to be released on February 18. The MJO is thought to be relatively unimportant during the winter but perhaps a strong El Nino increases the relevance of the MJO another research question for NOAA. 

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.

As I am looking at the below graphic Monday evening February 8, I still see a northern shifted weather pattern but with influence from the Southern Branch of the Jet Stream. This is the opposite of what one would expect with a strong El Nino so that again is something that needs to be explained. 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 Feb 2, 2016 Version and looking at Week 2 of that forecast. Mostly I see for the period February 10 –  February 16, 2016 a strong chance of above average precipitation for Northern Australia (not at all consistent with El Nino) but below average precipitation for parts of Brazil plus a moderate chance of below average temperatures for Florida (a frost risk possibility?). A small area of the Maritime Continent is forecast to have below average rainfall but it is a very small area. 

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.  In recent weeks, the projected location and strength of the Aleutian Low has varied a lot. On some days, the forecast is showing a split low with each of the two lows weaker than a combined single Low. Right now the forecasted Low has an hPa of 980 which is quite intense (the average in the winter is 1001hPa and 994 hPa for a non-split Low) but not quite as intense (i.e. it is higher) than recently. It is a split low with the less significant part over by Kamchatka where it influences the weather in Siberia. The largest part of this split low is a bit further west than is ideal for El Nino providing precipitation to California and points south. But the real problem is the strong High Pressure System  sometimes called the RRR which is off the West Coast of CONUS and is blocking storms reaching the West Coast from the Pacific. The rapidly shifting position of the Low makes a big difference in how storms are steered. With this forecast, one has a hard time figuring out what is going to happen. A longer discussion of the climate of Beringia and the role of the Aleutian Low is in Part II of this Report:  2. Medium Frequency Cycles such as ENSO and IOD. 

There is also a very large and strong High Pressure System forecast on Day 6 to be centered over Indiana and it will impact the entire East Coast and may even have wrap around impacts that impact the Southern Tier of CONUS.

Looking at the current activity of the Jet Stream one can certainly see how the Jet Stream is meandering but entering North America north of CONUS.

And here is the forecast out five days. It still shows the Jet Stream staying north for the Western part of CONUS.  Of course this is a forecast and changes daily or perhaps even more frequently. But not all weather is controlled by the Jet Stream (which is a high altitude phenomenon) but it plays a major role in steering storm systems.

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.

Here is 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 –  10 Day Outlook

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 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 FMA and the updated single month of February forecasts and then discuss the 8 – 14 day Maps and the 6 – 14 Day NOAA Discussion within that framework.

First – Temperature

Here is the Three-Month Temperature Outlook issued on January 21, 2016:

Here is the updated February Temperature Outlook.

Below is the current 6 – 10 Day and 8 – 14 Day Temperature 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 all winter as the patterns are moving from west to east fairly rapidly. As I view these two maps on February 8 (it updates each day), it appears that the third week of February may continue to exhibit the west/east division rather than the north/south division which continues to appear in the NOAA monthly and three-month outlooks.

6 – 10 Day Temperature Outlook

8 – 14 Day Temperature Outlook  

Now – Precipitation 

Here is the three-month Precipitation Outlook issued on January 21, 2016:

Here is the updated February Precipitation Outlook.

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 all winter as the patterns are moving from west to east fairly rapidly. As I view these two maps on February 8 (it updates each day), I am fairly amazed at the projected transition from the first week (which is what NOAA calls the 6 -10 Day Outlook) to the second week (which is what NOAA calls the 8 – 14 Day Outlook). Quite frankly I do not believe it and expect that it will be changed as the week evolves. It is certainly a big change from the computer (not reviewed by meteorologists) maps issued yesterday and reflects differences among the various forecasting tools and how they are weighted.

6 – 10 Day Precipitation Outlook

8 – 14 Day Precipitation Outlook 

Here are excerpts from the NOAA discussion released today February 8, 2016. It covers the full nine-day period and this week I have shown both the 6 -10 Day and the  8-14 Day Maps.

6-10 DAY OUTLOOK FOR FEB 14 – 18 2016

TODAY’S MODELS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER THE NORTH AMERICAN FORECAST DOMAIN FOR THE 6-10 DAY PERIOD. MODELS INDICATE A TROUGH OVER WESTERN ALASKA EXTENDING INTO THE NORTH PACIFIC, A RIDGE OVER WESTERN NORTH AMERICA, AND A TROUGH OVER EASTERN CANADA AND PARTS OF THE EASTERN U.S. THERE ARE SOME SIGNIFICANT DIFFERENCES BETWEEN THE ENSEMBLE PREDICTIONS OF THE ECMWF, NCEP GEFS AND CANADIAN MODELS, WITH THE ECMWF ENSEMBLE FORECASTING THE LOCATION OF THE TROUGH OVER THE EASTERN CONUS TO BE SOMEWHAT TO THE WEST OF THE LOCATION IN THE GEFS AND CANADIAN ENSEMBLE MODELS, WITH NEGATIVE HEIGHT ANOMALIES EXTENDING TO THE GULF COAST IN THE ECMWF.

DESPITE DIFFERENCES BETWEEN MODELS IN THE PREDICTED 500-HPA HEIGHT PATTERN FOR THE 6-10 DAY PERIOD, THERE IS GOOD AGREEMENT ON THE PREDICTED TEMPERATURE PATTERN. ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE FORECAST FOR ALASKA, WITH SOUTHERLY FLOW AHEAD OF THE TROUGH TO THE WEST, AS WELL AS FOR THE WEST AND CENTRAL CONUS AS FAR EAST AS THE WESTERN GREAT LAKES AND MISSISSIPPI VALLEY REGIONS, UNDER A PREDICTED RIDGE AND ABOVE NORMAL 500-HPA HEIGHT ANOMALIES.

DIFFERENCES IN THE RESPECTIVE HEIGHT FORECASTS OF THE ENSEMBLE PREDICTION SYSTEMS LEAD TO DIFFERENCES IN THEIR PRECIPITATION FORECASTS OVER THE FORECAST DOMAIN. MODELS AGREE ON ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR WESTERN ALASKA AND SOUTHERN ALASKA, INCLUDING THE ALASKA PANHANDLE, AS WELL AS NORTHERN AREAS OF THE PACIFIC NORTHWEST REGION AND THE WESTERN GREAT LAKES REGION. THE OFFICIAL PRECIPITATION FORECAST RELIES SOMEWHAT ON GUIDANCE FROM THE NCEP GEFS REFORECAST CALIBRATED PRECIPITATION AND THE NORTH AMERICAN ENSEMBLE FORECAST SYSTEM OR NAEFS, THAT CONSOLIDATES THE CANADIAN AND NCEP GEFS ENSEMBLE PREDICTION SYSTEMS. THE FORECAST CALLS FOR ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR PARTS OF SOUTHERN ARIZONA AND NEW MEXICO AND FOR WESTERN TEXAS, AND FOR ENHANCED PROBABILITIES OF BELOW MEDIAN PRECIPITATION FOR THE SOUTHEAST. THE ECMWF ENSEMBLE INDICATES A GREATER PROBABILITY FOR BELOW MEDIAN PRECIPITATION OVER THE SOUTHWEST AND ABOVE MEDIAN PRECIPITATION FOR THE SOUTHEAST THAN OTHER MODEL GUIDANCE, WITH A DIFFERENT PLACEMENT OF THE TROUGH OVER THE CONUS. [Editor’s note: In other words they do not know.]

FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN AND SOME DISAGREEMENT IN THE FORECAST TOOLS.

8-14 DAY OUTLOOK FOR FEB 16 – 22 2016 

MODELS ARE IN ONLY FAIR AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER THE NORTH AMERICAN FORECAST DOMAIN FOR THE 8-14 DAY PERIOD. MODELS PREDICT A TROUGH TO THE WEST OF ALASKA AS FOR THE 6-10 DAY PERIOD, HOWEVER WHILE THE NCEP GEFS MAINTAIN AN EXTENSION OF BELOW AVERAGE HEIGHT ANOMALIES INTO THE NORTH PACIFIC, THE ECMWF ENSEMBLE MEAN PREDICTS SMALLER HEIGHT ANOMALIES OVER THE NORTH PACIFIC. ABOVE NORMAL HEIGHT ANOMALIES CONTINUE TO BE PREDICTED FOR WESTERN NORTH AMERICA IN THE 8-14 DAY PERIOD BY THE NCEP GEFS ENSEMBLE, WHILE THE CANADIAN AND ECMWF ENSEMBLES PREDICT MUCH LOWER MAGNITUDE POSITIVE ANOMALIES OVER THE CONUS. AS FOR THE 6-10 DAY PERIOD FORECAST, THE PREDICTED TEMPERATURE PATTERN IS SIMILAR IN DIFFERENT MODEL FORECASTS, WHILE THERE ARE SIGNIFICANT DIFFERENCES IN THE PREDICTED PRECIPITATION PATTERN. THE OFFICIAL PRECIPITATION FORECAST AGAIN RELIES MORE ON THE NCEP GEFS REFORECAST CALIBRATED  PRECIPITATION AND THE NAEFS CONSOLIDATION OF THE CANADIAN AND NCEP GEFS ENSEMBLES.

PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE ENHANCED FOR ALASKA WITH PREDICTED SOUTHERLY FLOW. ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES ARE ALSO INDICATED FOR ALMOST THE ENTIRE CONUS, WITH THE EXCEPTION BEING PARTS OF THE SOUTHEAST, WHERE MOSTLY NEAR NORMAL IS INDICATED. BELOW NORMAL PROBABILITIES ARE GREATEST FOR THE FLORIDA PENINSULA. PREDICTED ABOVE NORMAL HEIGHTS OVER MUCH OF THE CONUS AND INCREASINGLY ZONAL FLOW LEAD TO A FORECAST OF WARMER TEMPERATURES RELATIVE TO THE 6-10 DAY PERIOD.

PROBABILITIES OF ABOVE MEDIAN PRECIPITATION ARE AGAIN ENHANCED FOR EASTERN  REGIONS OF THE SOUTHWEST AND WESTERN TEXAS, AS INDICATED BY THE GEFS AND NAEFS FORECAST TOOLS. THERE IS GOOD AGREEMENT AMONG THE ENSEMBLE MODELS ON THE FORECAST OF ENHANCED PROBABILITIES OF ABOVE MEDIAN PRECIPITATION FOR THE NORTHERN AND CENTRAL PLAINS ACROSS THE MISSISSIPPI VALLEY AND GREAT LAKES REGIONS INTO THE NORTHEAST. 

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE  TO GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN AND SOME DISAGREEMENT IN THE FORECAST TOOLS. 

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON FEBRUARY 18

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. This first set applies to the 5 and 7 day observed pattern prior to today. The second set which I am not using relates to the forecast outlook 6 – 10 days out to similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. That may also be useful information but they put this set of analogs in the discussion with the other set available by a link so I am assuming that this set of analogs is the most meaningful.

One thing that jumped out at me right away was the spread among the analogs from January 20 to February 17.  There are this time five El Nino Analogs and two ENSO Neutral Analogs and just one La Nina Analog suggesting that El Nino is again in full control over our weather for the next 6 – 14 Days. The phases of the ocean cycles in the analogs are clearly indicating McCabe Condition A which suggests that our weather may be wetter than suggested in the 6 – 14 Day 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.

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.

The Inactive Phase of the MJO had shifted to the Active Phase but that is coming to an end perhaps already has. So we should be seeing a decline in the SOI negative anomalies at least for a while until perhaps the second half of February and probably the peak has occurred.

The 30-day average, which is the most widely used measure, as of February 8 is reported at -12.91 which although it is definitely a reading that is associated with an El Nino (usually required to be more negative than -8.0 but some consider -6.0 value good enough) it is much lower (smaller negative number) than last week. The 90-day average remains in El Nino territory at -11.25 but is also lower than last week but the 90 Day Average moves much more slowly than the 30 day average. The SOI continues to be indicative of an El Nino Event in progress. 

Low-Level Wind Anomalies

Here are the low-level wind anomalies. In October, the area from 180W to 160W was of interest and quite intense. There then was an area of interest at 160W which also was quite intense. Now, calm appears to prevail but there recently was a WWB (Westerly Wind Burst) near and east of the Date Line related to Tropical Storm Pali which has long since dissipated. But look at the intensity of the wind anomaly associated with that WWB: 14 That might be “all she wrote” for this El Nino.

In the below graphic, you can see how the convection pattern recently appeared to be shifting ever so slightly a bit to the east but not as far east as we would expect with a strong El Nino. Now that slight movement to the East has reversed.

Let us now take a look at the progress of Kelvin Waves which are the key to the situation. The most extreme temperature anomaly colored gray in the graphic is now no longer there. We now focus on the next lower level of warm anomaly which also has exited the ONI/Nino 3.4 Measurement Area which runs from 170W to 120W. In fact it is now nowhere on the Equator. We are down to the next level of anomaly, the 1.5 to 2C anomaly, and it also is now out of the Nino 3.4 Measurement Area.The eastern movement of the more intense part of the warm anomaly is quite evident. This El Nino may be decaying quite rapidly. The decline in the temperature anomalies in the far Eastern Pacific show up here better than in some other graphics that I present. But you also see some warming from 120W to 150W which is related to yet another Kelvin Wave #5 which has now been declared by NOAA. This El Nino is dying but not without a fight. You can see all five of the Kelvin Waves which created this El Nino in this graphic. From the earliest to the most recent they can be named #1 through #5. I have been wrong before on Kelvin Wave #4 so I am hesitant to say this but it does look to me like Kelvin Wave #5 will not make it very far east and is already in its decline phase. But it does slow the retreat to the west of the Eastern Pacific Subsurface Warm Pool.

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

Top Graphic (Anomalies)

The above graphic 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 top graphic is still the most useful of the two and shows where 2C (anomaly) water is impacting the area in which the ONI is measured i.e. 170W to 120W. The 2C anomaly no longer extends to 180W but only to 170W which is an indication that the El Nino is losing ground.The 3C anomaly still extends to 160W but now exists only over to 130W. So I am viewing the 3C anomaly as encompassing only about 40% to 45% of the Nino 3.4 Measurement Area for the ONI along the Equator but even there not the full area from a latitude perspective which extends five degrees latitude to the north and south of the Equator. It explains why NOAA is coming up with lower ONI estimates. The 4C anomaly is not not even close to intersecting the surface. The 6C anomaly is now almost completely gone. One sees a small 0C anomaly at depth at about 100W. Water temperatures off the Coast of South America near the Equator are returning to normal.

Bottom Graphic (Absolute Values which highlights the Thermocline)

The bottom half of the graphic may soon become more 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 which pretty much looks like this as shown here during a Warm Event. You can see that the cooler water is not yet fully making it to the surface to the east along the coast of Ecuador. In fact, the 25C Isotherm no longer reaches the surface but the 26C isotherm reaches the surface on some days. We now will pay more attention to the 28C Isotherm as west of that temperature is where convection is more easy to occur. The 28C Isotherm has pretty much remained in the same place for months now but now appears to be migrating west consistent with this El Nino fading.

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. It is quite a bit less intense than on December 14. The 3.5C anomaly is no longer visible. The 3.0C anomaly now only shows in the center-west of the NINO3.4 Measurement Area. It also seems that in the center of the Nino 3.4 Measurement Area, the anomaly is broader north and south of the Equator possibly due to the recent Kelvin Wave activity. But it extends only to 160W and west of 140W. This means that in the calculation of the daily ONI, the estimate begins at the midpoint of the 3C to 3.499999C anomaly and is reduced by all the area that is in areas shaded less red. As of today (yesterdays readings from the TAO/TRITON buoys, the Easterlies are diminished (except east of 120W) but now show as Easterlies (albeit diminished) almost everywhere (top graphic) which is different than on October 4, 2015 when the anomalies were so strong that west of 150W they showed as having been converted into Westerlies. That is an indication that the conditions for maintaining this El Nino are eroding.

And an earlier but recent reference point re the bottom half of the TAO/TRITON Graphic.

If you look closely you can see that this El Nino has withdrawn somewhat to the West even in the short period of time since I froze the above January 19 TAO/TRITON graphic. 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 the past few weeks. The way I constructed the table, the 2.0 anomaly as an example includes water warmer than 2.0C so the 2.5C anomaly is included within it which you can tell by the way I recorded the westward and eastward coordinates. I could have constructed this table in a different way. 

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 February 8 in the afternoon working from the February 7 TAO/TRITON report, this is what I calculated.

My estimate of the daily Nino 3.4 ONI after rounding has declined to 2.4. NOAA has today reported the weekly ONI as being slightly higher at 2.6. It is difficult for me to see how they arrived at that level for the ONI Index. Nino 4.0 is again being reported as being 1.5 probably related to Kelvin Wave #5. Nino 3.0 is being reported as lightly lower at 2.2 which is significantly lower than last week which has to to with the timing of the surfacing of Kelvin Waves and their reflection to the west after they have surfaced. I believe it peaked at 3.7 during the El Nino of 1997/1998. This is one of many reasons for thinking that this El Nino is shifted to the west to some extent and is clearly significantly weaker than the 1997/1998 Super El Nino if you believe that the Nino 3.0 area is important and the Asian Meteorological Services do. The action which I think is most important to track right now is in Nino 1+2 which is now reported as being slightly higher at 1.2. The issue remains the extent to which warm water off of Ecuador and Peru impacts CONUS weather. I think it has very little impact except from the tropical storms that move up the west coast of Central America and sometimes contribute moisture to the circulation over CONUS. This phase of the El Nino seems to have come to an end. Most El Ninos decay from east to west so it will be observed most clearly first in Nino 1+2 and it is clear that this process has begun.

This is summarized in the following NOAA Table. I am only showing the currently issued version as the prior values are shown in the small graphics on the right with this graphic. Notice that other than NINO 4.0 (which has been propped up by Kelvin Wave #5), the other indices are trending lower and in the far end of the Tropical Pacific this decline rate has for one week at least increased. Curiously Australia had called for that to happen so perhaps their models take into account the individual Kelvin Waves and their movements to the east and then reflected back towards the west. 

One wonders about these calculations as they appear to not be related to the “adjusted” version of the NOAA forecast model which was discussed recently. So it is not clear to me how this El Nino will be officially recorded. October-November-December it seems was adjusted down a bit to having an ONI of 2.3. The new estimate for November – December – January has recently been released as being 2.3 and before rounding appears to exceed the highest three-month value for the 1997/1998 El Nino hence I am referring to this El Nino as being the most powerful El Nino in modern history as measured by NOAA.

In the NINO value historical graphics on the right, eyeballing it you might conclude that the three months were observed as being 2.9, 2.7 and 2.5 or a bit higher. So the impact of adjusting these observed values to what is considered “adjusted” is not obvious to me. If  2.9, 2.7 and 2.5 or 2.6 when averaged and adjusted by NOAA come to 2.3 how should we interpret the unadjusted weekly value of 2.6? To me (and some other knowledgeable folks) it is meaningless but I dutifully report it. It has to do with the two systems of calculating the base temperature profile. As per the discussion on the IRI/CPC Website:

OISSTv2 is often used for real-time analysis and model initialization, while ERSSTv4 is used for retrospective official ENSO diagnosis because it is more homogeneous over time, allowing for more accurate comparisons among ENSO events that are years apart. During ENSO events, OISSTv2 usually shows stronger anomalies than ERSSTv4, and during very strong events the two datasets may differ by as much as 0.5 C. Therefore, the anomalies cited below for this strong 2015-16 event are likely larger than those that will later be cited officially, particularly in comparisons with other strong El Niño events like 1997-98 and 1982-83.

The recent update of the ONI readings appears below.

Aside from quibbling over adjustments, there is no doubt that this El Nino has recorded an impressive string of ONI values and the other NOAA measurement system MEI is quite similar but downgrades this El Nino a bit compared to the 1982/1983 and the 1997/1998 El Ninos but it is a very small difference.

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.

Watching an El Nino evolve is like watching paint dry. The undercutting cool anomaly which had withdrawn to the west quite a bit is again expanding to the east but just a bit but the cold pool seems to have intensified. The subsurface warm water reservoir in the Eastern Pacific has not shown much sign of dissipating probably due to Kelvin Wave #5 but at 90W you can see signs of the colder water attempting to reach the surface. The grand switch appears to be setting up to happen.

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. 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. One can easily see the historical evolution of this El Nino and the “hot spots” that existed in December and which resulted in the very high ONI readings. But one can also see the western edge of the warm anomaly starting to shift to the East. You can see at the very bottom of this graphic, which shows the most recent readings, the easing of the extreme temperature anomalies in the Nino 3.4 Measurement area (see the scale on the right: red is less warm than dark red) namely 170W to 120W. That explains the slight reduction in NOAA ONI estimate. That is likely to continue to be the trend. You also see the decay in the anomalies from the east between 80W and 110W and even over to almost 140W but they are difficult to see with the resolution of this graphic.

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 of unfolded.

Again, there are changes from last week and remember this is a 30 day average and only seven days were added and seven days were removed. You can see the extreme moderating of the warm anomalies in the East LOL with a similar moderating of the cool anomaly in the West. You can see the dramatic decline of the wet anomalies in the Southwest which is more of a La Nina pattern than an El Nino pattern. These are significant changes which in my opinion are related to the westward displacement of this El Nino and the northern rather than southern entry of the Jet Stream.

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.

El Nino in the News

Nothing to report this week.

Putting it all Together.

The subsurface reservoir of warm water in the Eastern Pacific has reached its maximum and is now beginning to discharge. This would have occurred earlier if not for Kelvin Waves #4 and now #5. 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 the models seems increasingly likely to be a La Nina. One thing that is fairly certain for the U.S. based on historical patterns is that compared to this winter the following winter is likely to be:

The below is the CPC/IRI forecast issued on January 21, 2016.   We should be receiving an update soon.

Two weeks ago we suggested that it is possible the models 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. This new update from CPC/IRI suggests that his concept is not entering into their thinking. But the early and late month forecasts are based on different methodologies (forecasters early in the month and computer model results later in the month) so small differences may not be significant. This however is a big difference from what was presented two weeks ago

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.

D1. Introduction

D2. Climate Impacts of Global Warming

D3. Economic Impacts of Global Warming

D4. Reports from Around the World on Impacts of Global Warming