Written by Sig Silber
The Madden Julian Oscillation (MJO) is predicted to go into its inactive phase soon and that may impact this Northern El Nino in the upcoming weeks. It is likely to slow down the Jet Stream but it is not clear if it will change this strange pattern of precipitation which is more La Nina-ish than El Nino-ish for the Western Part of CONUS. The El Nino itself has begun to recede but atmospheric impacts last about two months longer than the index readings of the strength of an ENSO Event. But some of the forecasts might not work out as projected. We will get a new set of forecasts from NOAA on January 21. We will see if they have noticed that they are not getting it right.
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.
They are a bit relaxed about it but JAMSTEC has come out with their new ONI forecast.
It shows that this El Nino peaked in December and now is forecast to have significantly declined (hush do not tell the U.S. Media as it may ruin their circulation of outrageous articles) and they are forecasting a reasonably strong La Nina for next winter. Strong La Nina’s tend to have absolute values of their ONI index which are lower than the absolute value of the ONI index for strong El Ninos. The rapid decline of this El Nino is not particularly unusual but it may have impacts on the weather in last Winter and Early Spring. At the end of this report you will see that Australia has a slightly different perspective and thinks that this El Nino will score higher in February before beginning its decline. This would be due to the MJO but I think their timing may be off a bit. It is likely that the MJO will not be in its active state throughout February. The only reason these small differences are of any interest is that this El Nino is rated #2 or #3 in terms of how it records on various indices and it could edge into the #1 position. But they are really talking about February 1 which is only two weeks from now so they may turn out to be correct.
For those who do not believe in Global Warming…….SHUT YOUR EYES! or vacation in Ireland.
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 Western and an Eastern Ridge with a big trough in the center of CONUS. That means that one can decide what sort of weather one prefers and adjust their travel plans accordingly.
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 Great Lakes Area. The 540 Level general signifies equal chances for snow at sea level locations. The level of storm activity in the Western Pacific has picked up since the MJO has transitioned to its active phase. 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 January 18, I see a pattern which suggests that there is a deficiency in water vapor south and east of a line drawn from about El Paso, TX to Wilmington Del. The Northwest looks much more impressive. 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 Jan 12, 2016 Version and looking at Week 2 of that forecast. Mostly I see for the period January 20 – January 26, 2016 below average precipitation for Northern Australia and to a lesser extent the Maritime Continent with below average rainfall in the Amazon River Basin and a moderate chance of below normal precipitation and even cyclonic activity for Eastern Africa. The possible moderation of the drought re the Maritime Continent might be very significant.
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 976 which is quite intense (the average in the winter is 1001hPa and 994 hPa for a non-split Low). It is mainly a single unified Low but located just a bit further to the west than is ideal for El Nino but extends quite a bit to the south. There is also a small Low off of Kamchatka. The rapidly shifting position of the Low makes a big difference in how storms are steered. With this forecast, one can see how on Day 6, Pacific storms can easily enter CONUS south of Canada. But due to a miniature RRR in the picture, which is related to the northern expression of this El Nino, California is not receiving Pacific Storms directly. 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 an impressive Low off of Nova Scotia which could impact East Coast Weather.
Looking at the current activity of the Jet Stream one can certainly see how the Jet Stream is pretty much keeping things north at least in the Western half of CONUS.
And here is the forecast out five days which may be bringing some activity further south. 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. The slight gap between the El Nino warm anomaly and the Coast of Ecuador is of interest since this is a daily chart and more up to date than some other sources of information.
The two graphics below show first the changes over the four weeks (ending November 4) as compared to the above graphic which shows the current SST anomalies and then the changes over the four weeks ending on January 13, 2016. Looking at both of these change in anomaly graphics is helpful in putting the current situation shown above into perspective.
First the four weeks ending on November 4, 2015
I am also showing the new version issued today which basically shows the changes over the last month in the Sea Surface Temperature anomalies. It is approximately ten weeks later than the above graphic which you can tell by checking the dates in the graphic. You can clearly see the cooling pattern in the Pacific and since these are “departures” or “anomalies”, it is not a seasonal pattern that is being shown. You can clearly see the weakening of the El Nino especially off of Ecuador and now Peru also and the warming off the coast of Central America has ceased. The cool anomaly off of Beringia has moved south to some extent and the PDO+ pattern has diminished or possibly even reversed which you can not tell from this graphic alone. The waters off of the East Coast of North America no longer show continued warming from the already warm levels. Overall, the changes this week are again somewhat muted but important. The receding of the El Nino from the Coast of South America is the most significant change.
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 available in Part II of this report.
To put the forecasts which NOAA tends to call Outlooks into perspective, I am going to show the three-month JFM and the “early” single month of January 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 December 17, 2015:
Here is the January Temperature Outlook issued on December 31, 2015.
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 January 18 (it updates each day), it appears that the last week of January may just be warmer than climatology all over.
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Now – Precipitation
Here is the three-month Precipitation Outlook issued on December 17, 2015:
And here is the month of January Precipitation Outlook which was issued on December 31, 2015.
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 January 18 (it updates each day), it appears that the last week of January may begin by continuing the recent pattern of a wet Northwest and a wet extreme Southeast without the extremely wet Southwest which is usually associated with a strong El Nino. Then the increasing progressive nature of the pattern may extend the wet area to cover almost all of CONUS.
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook Notice the somewhat northern displacement of the precipitation which is not usual during a strong El Nino.
Here are excerpts from the NOAA discussion released today January 18, 2015. 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 JAN 24 – 28 2016
TODAY’S ECMWF, GFS, AND CANADIAN ENSEMBLE MEAN SOLUTIONS ARE IN VERY GOOD AGREEMENT ON THE PREDICTED 500-HPA FLOW PATTERN OVER THE FORECAST DOMAIN. A VERY ANOMALOUS TROUGH IS FORECAST IN THE EASTERN PACIFIC, EXTENDING OVER MUCH OF WESTERN ALASKA. ANOMALOUS RIDGING IS FORECAST ALONG THE WEST COAST, WITH ANOMALOUS TROUGHING FORECAST OVER THE REST OF THE CONUS. RECENT DETERMINISTIC GFS AND ECMWF MODELS ARE ALSO IN VERY GOOD AGREEMENT WITH THEIR RESPECTIVE ENSEMBLE MEANS, INCREASING CONFIDENCE IN THE PREDICTED 6-10 DAY PATTERN.
ABOVE NORMAL TEMPERATURES ARE FAVORED ACROSS THE ENTIRE U.S., EXCEPT FOR THE FLORIDA PENINSULA, DESPITE SOME AREAS OF NEGATIVE 500-HPA ANOMALIES. ANOMALOUS SOUTHERLY FLOW SUPPORTS ABOVE NORMAL TEMPERATURES FOR ALASKA, ANOMALOUS RIDGING FAVORS ABOVE NORMAL TEMPERATURES FOR THE WESTERN U.S., AND, DESPITE THE MEAN 500-HPA HEIGHTS BEING BELOW NORMAL FOR PARTS OF THE PLAINS AND MISSISSIPPI VALLEY, FORECAST PERIODS OF ANOMALOUS WARMING FAVORS ABOVE NORMAL TEMPERATURES FOR MOST OF THE REST OF THE CONUS.
AS A STRONG STORM SYSTEM IS PREDICTED TO MOVE ONSHORE DURING THE BEGINNING OF THE 6-10 DAY PERIOD, ABOVE MEDIAN PRECIPITATION IS FAVORED FOR COASTAL PORTIONS OF SOUTHERN ALASKA, THE ALASKA PANHANDLE, AND THE PACIFIC NORTHWEST. THE CHANCES FOR BELOW MEDIAN PRECIPITATION ARE INCREASED OVER PARTS OF NORTHERN ALASKA, ASSOCIATED WITH RELATIVELY DRY LOW LEVEL FLOW PREDICTED TO ORIGINATE FROM CANADA. DUE TO FORECAST RIDGING, BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHWEST. [Editor’s Note: We have noted the northern displacement of the impacts of this El Nino particular as it impacts the Western Half of CONUS.] BELOW MEDIAN PRECIPITATION IS ALSO FAVORED FOR PARTS OF THE ROCKIES AND PLAINS BEHIND THE TROUGH CENTERED OVER THE EAST CENTRAL CONUS. A STORM SYSTEM PREDICTED TO FORM OVER THE SOUTHEAST IN THE LATER PART OF THE 6-10 DAY PERIOD INCREASES THE LIKELIHOOD FOR ABOVE MEDIAN PRECIPITATION IN THE SOUTHEAST AND MIDATLANTIC.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO VERY GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN, OFFSET BY ONLY FAIR AGREEMENT AMONG THE FORECAST TOOLS.
8-14 DAY OUTLOOK FOR JAN 26 – FEB 01, 2016
THE PREDICTED 500-HPA FLOW PATTERN DURING THE WEEK-2 PERIOD IS SIMILAR TO THAT IN THE 6-10 DAY PERIOD, EXCEPT LESS AMPLIFIED. THE RIDGING OVER THE WEST COAST IS EXPECTED TO WEAKEN AS MORE SHORTWAVE ENERGY IS PREDICTED TO COME ONSHORE, AND THE OVERALL PATTERN IS FORECAST TO BECOME MORE PROGRESSIVE. THE TEMPERATURE PROBABILITY FORECAST IN THE WEEK-2 PERIOD IS VERY SIMILAR TO THAT IN THE 6-10 DAY PERIOD. THE PRECIPITATION PROBABILITY FORECAST IN THE WEEK-2 PERIOD CONTAINS A MUCH LARGER AREA FAVORING ABOVE MEDIAN PRECIPITATION DUE TO THE MORE PROGRESSIVE PATTERN AND MORE STORM SYSTEMS EXPECTED TO TRACK ACROSS THE CONUS DURING THE PERIOD.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE TO VERY GOOD MODEL AGREEMENT ON THE 500-HPA PATTERN, OFFSET BY ONLY FAIR AGREEMENT AMONG THE FORECAST TOOLS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON JANUARY 21
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.
Analog Centered Day | ENSO Phase | PDO | AMO | Other Comments |
Dec 31, 1957 | El Nino | + | + | |
Jan 25, 1958 | El Nino | + | + | |
Jan 27, 1966 | El Nino | – | – | |
Jan 15, 1970 | El Nino | N | – | |
Jan 18, 1970 | El Nino | + | – | |
Dec 28, 1976 | El Nino | + | – | |
Dec 28, 2001 | La Nina | – | + | Powerful La Nina |
Dec 29, 2001 | La Nina | – | + | Powerful La Nina |
Jan 14, 1998 | El Nino | + | + |
One thing that jumped out at me right away was the full-month spread among the analogs from December 28 to January 29 which is about the same as last week. Having four December analogs when today is January 18 and the analogs are centroids of periods that preceded today is consistent with the warmer than usual temperatures forecast for this time of the year. There are this time seven El Nino Analogs and two La Nina Analogs suggesting that El Nino is finally in full control over our weather for the next 6 – 14 Days. The phases of the ocean cycles in the analogs are not clear. 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 |
Jan 12 | -17.7 | -13.05 | -11.26 |
Jan 13 | -16.7 | -13.45 | -11.09 |
Jan 14 | -21.4 | -13.87 | -11.19 |
Jan 15 | -24.5 | -14.31 | -11.42 |
Jan 16 | -24.2 | -14.90 | -11.68 |
Jan 17 | -32.1 | -16.07 | -11.93 |
Jan 18 | -19.6 | -16.80 | -12.03 |
The Inactive Phase of the MJO has played out and has shifted to the Active Phase and we have been seeing strong negative readings all week. It has been dry in Darwin and rainy in Tahiti. The 30-day average, which is the most widely used measure, on January 18 is reported at -16.80 which is substantially stronger than last week and 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). The 90-day average has not really changed much but remains in El Nino territory at -12.03. The SOI continues to be indicative of an El Nino Event in progress. But the MJO will soon transition to its Inactive Phase and the SOI values should moderate.
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 that is changing as the MJO changes phase and becomes more active. There is a WWB (Westerly Wind Burst) near and east of the Date Line related to Tropical Storm Pali which by now has probably dissipated. Will it lead to another Kelvin Wave? If so, that will probably not have much of an impact on the final rating of this El Nino due to the fact that we are already in January. But it will contribute to the strange western characteristic of the warm anomaly along the Equator.
In the below graphic, you can see how the convection pattern may be shifting a bit to the west. Actually perhaps quite a bit to the west. The anomalies however are much stronger right now than in November when they seemed to vanish.
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 125W to 175W which may signify yet another Kelvin Wave. This El Nino is dying but not without a fight.
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 so that may be starting but has not progressed to any large extent as yet but there are signs that it is beginning.
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 now extends to 180W which is very impressive but seems to be losing ground.The 3C anomaly now extends to beyond 160W but not to 170W as it did last week. So I am viewing the 3C anomaly as encompassing about 80% of the Nino 3.4 Measurement Area for the ONI along the Equator but 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 high ONI estimates. The 4C anomaly is now not intersecting the surface. The 6C anomaly is almost gone.
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 does but barely. 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.
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.
And then the December 14 version which I “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 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 east of 160W and west of 120W. 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.
———————————————– | A | B | C | D | E | —————- |
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.
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 January 18 in the afternoon working from the January 17 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | 2.2 | 2.0 |
B. 160W to 150W | 2.7 | 2.7 |
C. 150W to 140W | 2.8 | 2.9 |
D. 140W to 130W | 2.7 | 2.8 |
E. 130W to 120W | 2.5 | 2.7 |
Total | 12.9 | 13.1 |
Total divided by five subregions i.e. the ONI | (12.9)/5 = 2.6 | (13.1)/5 = 2.6 |
My estimate of the daily Nino 3.4 ONI after rounding is again 2.6. NOAA has today again reported the weekly ONI as being 2.6 . Nino 4.0 is reported as being 1.3 which is a bit lower than last week. Nino 3.0 is being reported as 2.8 a bit higher 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. The action which I think is most important to track right now is in Nino 1+2 which is now reported as being 1.4 which is quite a bit lower than last week. 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. These part of an 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 seems 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.
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 has now been recorded as having an ONI of 2.3. In the NINO value historical graphics on the right, eyeballing it you might conclude that the three months were observed as being 2.5, 2.9 and 2.7. So the impact of adjusting these observed values to what is considered “adjusted” is not obvious to me. If 2.5, 2.9, and 2.7 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. I believe it has to do with the two systems of calculating the base temperature profile and I might try to shed some light on this in a future issue of this Weather and Climate Report. It has to do with the differences between CFSv2 and ERSST.v4.
The above, which I also included last week, is the recent portion of the ONI history and notice it is based on the ERSST.v4 system of determining the temperature anomalies. The full history of the ONI readings can be found here.
Although I discussed the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures.
I see some change week to week as watching an El Nino evolve is like watching paint dry. The undercutting cool anomaly has withdraw to the west quite a bit. The subsurface warm water reservoir in the Eastern Pacific is dissipating but slowly.
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 also the current “hot spots” that are showing up and leading to 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 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 moderating of the warm anomalies in the East. You can see the decline of the wet anomalies in the Southwest. And you can see that Northern Mexico is dry without the hurricanes. These are not huge changes but they paint a picture.
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.
View from Australia
El Nino
Here is the discussion just released:
Tropical activity slows El Niño decline
Issued on 19 January 2016
A strong El Niño persists, but ocean temperatures in the tropical Pacific are showing a gradual cooling signal. Climate models suggest El Niño will decay over the coming months, with a likely return to neutral conditions in the second quarter of 2016.
The eastern tropical Pacific sub-surface has cooled by up to 3 degrees since late November. Weekly sea surface temperatures likewise show a cooling trend, evident since late November. However, recent tropical cyclone activity in the central tropical Pacific has produced strong westerly winds along the equator which may temporarily slow the decline of El Niño. Such short-term re-intensification of El Niño has happened before. For example, 1997–98 saw a re-strengthening of El Niño conditions in early 1998, before the event eventually decayed.
Based on the 26 El Niño events since 1900, around 50% have been followed by a neutral year, and 40% have been followed by La Niña. Models also suggest neutral and La Niña states are about equally likely for the second half of 2016, with a repeat El Niño the least likely outcome. Historically, the breakdown of strong El Niño events brings above average rainfall to parts of Australia in the first half of the year.
The Indian Ocean Dipole has little influence on Australian climate between December and April. However, Indian Ocean sea surface temperatures remain at record warm levels across the majority of the basin. This basin-wide warmth may provide extra moisture for rain systems across Australia.
Next update expected on 2 February 2016
IOD (Indian Ocean Dipole)
The graphic comes with only a very short discussion and here is that discussion:
The Indian Ocean Dipole (IOD) is neutral. The index value to 17 January was −0.37 °C.
Sea surface temperatures (SSTs) remain significantly warmer than average across most of the Indian Ocean basin, with the southern hemisphere Indian Ocean continuing its run of monthly record temperatures, with the warmest December on record.
The IOD is usually neutral during the months December to April and therefore is not considered to have an impact on Australian climate at this time of year (when the monsoon trough shifts south over the tropical Indian Ocean). However, widespread record-warm sea surface temperatures across the Indian Ocean may influence Australian climate during the summer months. These warm waters act as a source of moisture, and may provide extra moisture for rainfall systems developing over Australia.
The interrelationship between the IOD and El Nino is complicated and not fully understood.
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 possibly #5. This El Nino has peaked in intensity and is now in rapid decline. However the Australian forecasters do not agree and see one more move up in the ONI Index for February before the decline sets in.
The impacts in the Indian Ocean seem to have peaked and are moderating. Same goes for the Western Pacific. Now the focus shifts to North and South America. But this remains a very strong El Nino but perhaps no longer a Super El Nino. There is a debate going on as to whether or not this El Nino will be rated as a “Super El Nino”. Not that this is important but it will be a close call. The impacts of an El Nino on CONUS tend to lag the Index values by about two months. The best bet is that it will behave more like the two strong El Ninos which occurred with PDO+ than the one that occurred with PDO-. The three geographic areas I used to categorize regional impacts are all likely to be wetter than normal/climatology. But the Southeast is not likely to be as wet as it was the case with the 1997/1998 El Nino. We are currently having flooding in the middle and southern Mississippi river but that is further west than was the case with the 1997/1998 Super-El Nino. So far, the impacts to CONUS appear to be shifted further north and perhaps west than usual for an El Nino. That may change as the winter unfolds but that is by no means certain.
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:
- warmer in the south and less warm in the north and
- more dry in the south and less dry in the north.
The below is both CPC/IRI forecast issued on December 17, 2016 and the forecast issued on January 14, 2016. The more recent forecast shows a steep decline of this El Nino. La Nina is not even considered for the AMJ three-month period in the earlier forecast but now shows up as a low-probability event in both the MAM and AMJ three-month periods. On the other hand, the probabilities for La Nina are slightly reduced for the ASO three-month period.
Last week 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 update from CPC/IRI suggests that his concept may be finally entering into their thinking. But the early and late month forecasts are based on different methodologies so small differences may not be significant.
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