The science theme tonight is Modokis for which we, to a large extent, thank JAMSTEC. We will also cover the mature and declining phase of this quasi-La Nina which NOAA recently, just as the quasi-La Nina was entering the decline phase, declared "La Nina Conditions Apply" which was eerily similar to the call reversed a week later of the El Nino of 2014/2015. This raises questions. The late call, which itself was debatable, could simply be a debatable interpretation that should have been made two months earlier, a rush to take credit, or something much more concerning. Of course we will tonight also cover the forecasts for the U.S. and World. Lots to cover for a week without a major NOAA data release.
First some housekeeping information. Working on a Glossary of Terms but right now it is empty. But, at some point, it will be possible to look up acronyms etc by going to the GEI Weather Page Glossary. Also for those who want the forecasts beyond three months, we reported previously on the November 17 NOAA 15 Month Forecast and compared the first ten months of the NOAA Outlook with that of JAMSTEC in a special Update that you can get to by clicking here. We will of course publish a new 15 Month Update Report shortly after December 15, 2016. Remember if you leave this page to visit links provided in this article, you can return by hitting your "Back Arrow", usually top left corner of your screen just to the left of the URL box.
Thinking About JAMSTEC.This presentation may help explain what they do. It is a separate agency from the Japanese Meteorological Agency (JMA) and quite frankly I think they are very competitive with each other and have some overlap in what they do. It is a very interesting situation.
Of particular interest is JAMSTEC's work on ENSO Modoki. The primary credit goes to Kamururi Ashok and this 2007 Paper provides the first detailed report on this (although I think another team also reported on the Modoki in 2007). The impetuous for the work by Ashok et al was from a Japanese Reporter who noticed something strange about the 2004 El Nino. I believe the Ashok team developed the formula for the Modoki Index used by JAMSTEC and others today. Today I believe that Dr. Ashok is currently associated with the Indian Institute of Tropical Meteorology (and I believe he moved to Korea (APEC Climate Center, Busan, Republic of Korea) shortly after publishing this paper, making my point that when it comes to understanding the tropics, Asia is more advanced than the U.S. And yet the tropics are a major control of CONUS weather. This is a problem that needs to be addressed. ·
Although ENSO Modoki was not necessarily discovered by Japan, they pay the most attention to the differences in ENSO events especially what is called a Modoki (meaning similar but different).That may not be totally correct as much Modoki research has been funded and performed in the U.S., but somehow it does not filter up to NOAA forecasts (large bureaucracy perhaps or many other possible reasons). So we look to Japan for focusing in on the various "flavors" of ENSO phases. For CONUS, it seems to make the most difference in the Warm Phase but it does have some impacts in the Cool Phase also but La Nina Modoki may create the most impact in the Western Pacific where it impacts storm tracks which is of great Interest to the Chinese.
The NOAA approach is to look exclusively at the Nino 3.4 area of the Tropical Pacific which is defined as 170W-120W, 5N-5S and to consider the sea surface temperature anomaly (SSTA) in only that area.
The JAMSTEC approach is to look at the Nino 3.4 temperature anomaly just as NOAA does but also use the Ashok formula which is EMI = [SSTA]A-0.5x[SSTA]B-0.5x[SSTA]C where the A anomaly is calculated in the region 165E -140W,10S-10N, B is 110W-70W, 15S-5N, and C is 125E-145E,10S-20N
So there is some overlap but the EMI pays more attention to the waters to the west of Nino 3.4. The Chinese pay more attention to the waters to the East of Nino 3.4
There is more to it than just the indices and U.S. researchers may actually have discovered the problem before the Japanese. Trenberth and Stepaniak at NCAR in 2001 introduced the Trans-Nino Index (TNI) which approaches the problem from the Eastern End of the Tropical Pacific. NOAA is fully aware of all of this as this article shows. But they insist on not using the information for some unexplained reason. One reason provided to me by someone who works for NOAA is that it is too complicated for Americans to understand. Perhaps he is correct.
The graphic below from the above linked article and the excerpt from the discussion in that paper applies to El Nino rather than La Nina but it shows that NOAA is well aware that the location of ENSO SSTA has an impact even if they are not willing to use that information.
The labeling of longitude on this graphic is interesting and correct but not necessarily the normal way to do it. Usually 180E is labeled the Dateline and from there further east one subtracts the degrees E from 360W so that 200E would become 160W and 260E would become 100W which is close to the coast off of Ecuador. The Earth is a sphere so you can travel around it on the Equator by going east or west and it is easier to follow if the convention used with most maps is employed.
Scatterplot of the relationship between the maximum sea surface temperature anomaly (y-axis) and its location in the equatorial Pacific Ocean (x-axis showing longitude). Data is based on a 4,000 year pre-industrial control run of the NOAA GFDL CM2.1 model. Figure courtesy of Andrew Wittenberg and modified by climate.gov.
In general, it shows that the farther east the location of largest SST anomalies is (farther right on the horizontal axis), the stronger the event (higher on the vertical axis). As the location of the biggest anomalies shifts toward the central tropical Pacific, the SST anomalies become weaker. In other words, ENSO strength and ENSO flavors go hand in hand .
This relationship brings us to a rule-of-thumb: Weaker El Niños tend to be closer to the Central Pacific types and stronger El Niños tend to be closer to Eastern Pacific types.
Like all rules-of-thumb, this one will not apply to every case (in the figure above, notice the smaller cluster of weak El Niños that also peak in the eastern Pacific), but it will work for the majority of them.
JAMSTEC provides forecasts of the Nino 3.4 Index that NOAA relies on also their own Modoki Index. They are shown side by side below.
One has to be careful with the side by side comparison because the Y Axis in the two graphics is different.
First let's examine the JAMSTEC Nino 3.4 forecast.
One thing to look at is the duration of the period when the index is -0,5 or less which appears to be here from July to March or nine months which if the Spring part of that forecast works out as shown might make this a true La Nina.
Now we look at the JAMSTEC La Nina Modoki Index forecast
Here the duration of the index being -0.5 or less is from Sept to January or five months which is not sufficient to make this a declared La Nina
This raises a lot of questions of interpretation. Is JAMSTEC incorrect that this is a Modoki? BTW they are not sure. It is a lot easier to differentiate a Typical El Nino from a El Nino Modoki than a Typical La Nina from a La Nina Modoki. Research is ongoing. This is a situation where we probably will only be able to resolve it after the fact if at all.
Impacts on Walker Circulation
Perhaps the biggest impact of ENSO is the change in the Walker Circulation. What is the Walker Circulation? If is pretty simple. Where the Equator is warm, there is increased evaporation and thus convection and clouds rise. Since these clouds rise, the warm moist air must subside somewhere else usually over cool water or land in the form of precipitation. That is pretty much what the ENSO Cycle is all about. Where clouds are generated and where precipitation falls.
There are many graphics that show this. I came across this one and like it. I am having difficulty finding the source of this graphic. Kurt G. Baldenhofer seems to be the webmaster on that site.I have not gone through his site to determine the ultimate source of the below graphic so I apologize if I am not giving the creator of this graphic proper attribution.
Here is my feeble attempt to translate the German into English.
The color describes the deviation from normal i.e. warm, cool, normal.
With La Nina conditions, you have strong trade winds in the Pacific Ocean, the warm water is driven towards Southeast Asia. This causes cool water at depth to rise causing the surface of the Ocean off of Peru to be cool.
With El Nino warm water flows back towards the East.Thus the water temperature off the coast of Peru rises. The moisture content of the atmosphere rises and precipitation increases.
La Nina Modoki:
With La Nina Modoki, the wind drives the warm water both to the East and West. Thus the Central Pacific cools.
El Nino Modoki
With El Nino Modoki, wind blows in from opposite directions. Thus the Central Pacific warms.
The descriptions in the graphic are incomplete as there are many variations (including Modoki Type I and Type II which we are not getting into this evening) but the main value of the graphics is that you can see that with a La Nina Modoki, the cool anomaly in the Pacific along the Equator is further west than with a Traditional La Nina. This means the Walker Circulation is westerly displaced just as with the most recent El Nino, the Walker Circulation was also shifted to the west. With a Modoki, you may get two Walker Cells rather than one (this is where the graphic may be oversimplifying the situation) and the result may be that a La Nina Modoki may tend to resemble to some extent an El Nino. That really is the key part. It is not sufficient to characterize ENSO Events as either El Nino, La Nina, or Neutral.
The problem is that this Fall/Winter is not exactly a La Nina Modoki but it is not exactly a Traditional or Canonical (another word for the same thing) La Nina either. Thus the statistical methods used by NOAA do not work very well for forecasts beyond 2 weeks or perhaps a month. The Dynamic forecasts which are used for shorter term forecasts do not care about labels so they are not impacted by this discussion and thus those models work just fine. It is only when we are attempting to use history to forecast far into the future that we get into trouble as the immediate history (the analogs use to some extent in the NOAA 6 - 14 Day forecast have sound theoretical basis i.e. if conditions similarly to today in the past, 6 - 14 days later produced a certain kind of weather, that may tell us what the next two weeks will look like. With today's very powerful computers, the models go way beyond just relying on analogs but deal in much more detail. But when trying to predict the weather 2 to 6 months out, the correct assessment of the ENSO state becomes an important part of the process and the statistical methods employed by NOAA break down as they deal only in how intense the current ENSO event is relative to historical ENSO events of similar intensity. But in the U.S., that approach totally ignores the "flavor" of the current ENSO event as compared to the "flavor" of historical ENSO events.
It is understandable that NOAA does not want to go there because the database does not have a sufficient number of ENSO events of different flavors and we have only discussed two i.e. Typical/Canonical and Modoki. There are more variations or flavors as they are sometimes called.
So it is understandable but it is not excusable as Japan i.e. JAMSTEC is able to take this challenge on with I am sure a smaller but not small staff. NOAA can do better. NOAA needs to do better. Right now most funding goes to Global Warming. But we live in 2016 and it might be nice to be able to predict weather in 2016 and not just year 2100. And the two topics are not unrelated as Global Warming may be resulting in more Modokis.
Thus we end up with this:
So comparing the two top (monthly forecasts that rely a lot on statistical techniques) with the two bottom graphics (Week 3 - 4 forecasts relying on mostly dynamic modeling), it looks like the (mostly) statistical temperature forecast for December made on November 17 was not a good predictor of temperature for mid-December or at least the more recent dynamical forecasts do not see it the same way but on the other hand the statistical method seems to have been a good forecast for precipitation or at least the dynamical forecast issued on November 25 agrees with the earlier (mostly) statistical based forecast. The date of preparation of these forecasts only differs by week. But the methodology was very different.
It is not very explicit but I believe the November 20 discussion by the Australian Bureau of Meteorology also hints at a Modoki situation rather than a traditional La Nina.
In the tropical Pacific, most indicators of ENSO are well within neutral bounds. In the past fortnight, sea surface temperatures in the central tropical Pacific Ocean have warmed once again, further dampening chances of La Niña. The Southern Oscillation Index (SOI) has been negative since late October (La Niña values are typically positive) but remains neutral. Trade winds are currently close to average. Only cloudiness near the Date Line continues to show some La Niña-like characteristics.
In conclusion, I am trying to make the point that Asian Meteorological Agencies may be able to make seasonal forecasts for the U.S better than NOAA because they have a better understanding of ENSO and perhaps of the PDO also.
A. Focus on Alaska and CONUS (all U.S. except Hawaii) - Let's Focus on the Current (Right Now to 5 Days Out) Weather Situation.
First, this graphic provides a good indication of where the moisture is. It is a bit different than just moisture imagery as it is quantitative.
To turn the above into a forecasting tool click here and you will have a dashboard for a short-term forecasting model.
Notice that right now the major moisture inflow is subtropical from the Gulf of Mexico. This is probably the Pacific Storm that impacted Arizona and New Mexico earlier this week.
Here is a national animation of weather fronts 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 links provided below.
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.
U.S. 3 Day to 7 Day Forecasts
Below is a graphic which highlights the forecasted surface Highs and the Lows re air pressure on Day 3. The Day 6 forecast can be found here.
The Aleutian Low It is now shown as a large non-split Low with central air pressure of 984 hPa centered pretty much as one expect with ENSO Neutral. The average sea level air pressure in the winter is 1001 hPa and 994 hPa for a non-split Low. This graphic changes every six hours.
The High Pressure off of California, the familiar RRR, is there (1032 hPa). Thus, right now the RRR is doing a fairly good job of protecting the West Coast from Pacific storms and also providing northerly winds for California. The NOAA forecasts do not seem to recognize the good job the RRR is doing to prevent Pacific Storms from impacting CONUS or NOAA expects the configuration to change. But a Rex Block or similar translates a higher latitude storm to lower latitudes although the pattern right now has the high much further south and if you considered the Low in the Gulf of Alaska one might look at this pattern as an Omega Block. There are many ways to look at this pattern but they all end up having storms enter the Northwest or British Columbia and drop down via the Great Basin and impact the Southwest. It has been the prevailing pattern lately and the meridional flow has allowed storms to enter from the north but drop down and impact the Southwest to some degree. NOAA today seems to be forecasting a change in this pattern to one that is more Zonal or Progressive with storms moving more directly across CONUS. .
I provided this K - 12 write up that provides a simple explanation on the importance of semipermanent Highs and Lows and another link that discussed possible changes in the patterns of these highs and lows which could be related to a Climate Shift (cycle) in the Pacific or Global Warming. Remember this is a forecast for Day 3. It is not the current situation but Day 3 is not very far out.
The various High Pressure Systems in the Arctic are of interest re the Arctic Oscillation (AO). It is forecast by this graphic and other sources to be less significant for a while.
Here is the seven-day precipitation forecast. More information is available here.
What you are seeing here is mostly a band of precipitation stretching from Southeast Texas to Maine.
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. Because "Thickness Lines" are shown by those green lines on this graphic, it is a good place to define "Thickness" and its uses. The 540 Level general signifies equal chances for snow at sea level locations. Remember that 540 relates to sea level.
Thinking about clockwise movements around High Pressure Systems and counter- clockwise movements around Low Pressure Systems provides a lot of information.
What you can see in the above graphic is a deep trough for the Intermountain West and a Great Lakes Ridge. It looked a lot different on Sunday. Remember this is a forecast for Day 7. Note the 540 Thickness Line re the above discussion of thickness and snow likelihood.
The graphic below is the Eastern Pacific a 24 hr loop of recent readings. It does a good job of showing what is going on right now. The winds and moisture approaching the West are of most interest.
The graphic below (which is a bit redundant with the above) updates automatically so it most likely will look different by the time you look at it as the tropical weather patterns unlike the patterns north of 30N are generally moving from east to west but right now are moving from west to east. This graphic highlights tropical activity. Unlike the above which shows recent history, the below graphic is a satellite image with the forecast of tropical events superimposed on the satellite image. There is no significant "new" tropical activity that would appear to impact CONUS forecast for the beginning of this week.
We can track tropical storms here. Former Hurricane Otto is no longer being reported on by the NHC but you may be able to to see the remains of it in the graphic above. It may well combine its remaining moisture with the stream of moisture coming in via the split Jet Stream. .
We can still see Otto (although it is not marked) which is an Atlantic Basin Hurricane has crossed Costa Rica and remains a fading tropical event. Elsewhere you might see that it is over fairly cool water right now. .
Below is the current water vapor Imagery for North America.
Tonight, Monday evening November 28, 2016 (and this is the current situation not an animation of recent history), as I am looking at the above graphic, we see mostly the leading edge of the prior Pacific Trough.
Looking at the current activity of the Jet Stream.
First the current situation. Not all weather is controlled by the Jet Stream (which is a high altitude phenomenon) but it does play a major role in steering storm systems. The sub-Jetstream level intensity winds shown by the vectors in this graphic are also very important in understanding the impacts north and south of the Jet Stream which is the higher-speed part of the wind circulation and is shown in gray on this map. In some cases however a Low-Pressure System becomes separated or "cut off" from the Jet Stream. In that case it's movements may be more difficult to predict until that disturbance is again recaptured by the Jet Stream. This usually is more significant for the lower half of CONUS i.e. further south than the Jet Stream.
One sees the jet stream diving into the Southwest which has brought a series of storms to the Southwest and from there they travel in a northeast direction.
Now looking at the 5 Day forecast;
You can see the same pattern with more of a split stream shown. Some forecasts do not show the pattern entering CONUS and then passing back over the Pacific to recharge its moisture but staying inland and drying out before it reaches the Southwest. Small changes can have large impacts.
Putting the Jet Stream into Motion and Looking Forward a Few Days Also
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.
When we discuss the jet stream and for other reasons, we often discuss different layers of the atmosphere. These are expressed in terms of the atmospheric pressure above that layer. It is kind of counter-intuitive to me. The below table may help the reader translate air pressure to the usual altitude and temperature one might expect at that level of air pressure. It is just an approximation but useful.
Re the above, H8 is a frequently used abbreviation for the height of the 850 millibar level, H7 is the 700 mb level, H5 is the 500 mb level, H3 is the 300 mb level. So if you see those abbreviations in a weather forecast you will know what they are talking about.
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. This amazing graphic covers North and South America. It could be included in the Worldwide weather forecast section of this report but it is useful here re understanding the wind circulation patterns.
Four- Week Outlook
I am going to show the three-month DJF Outlook (for reference purposes), the Updated Outlook for the single month of November, the 6 - 10 Day and 8 - 14 Day Maps and the Week 3 - 4 Experimental Outlook. I use "EC" in my discussions although NOAA sometimes uses "EC" (Equal Chances) and sometimes uses "N" (Normal) to pretty much indicate the same thing although "N" may be more definitive.
First - Temperature
Here is the Three-Month DJF Temperature Outlook issued on November 17, 2016:
Here is the Early Temperature Outlook for December Issued on November 17, 2016
6 - 10 Day Temperature Outlook Issued Today
8 - 14 Day Temperature Outlook Issued Today
Looking further out.
As I view these maps (which have dramatically changed since the maps generated by the unsupervised computers were released yesterday) on Monday November 28 (two of the five update each day and one (the Week 3 - 4 Outlook) updates every Friday, it appears that the pattern during December 4 to December 12 will start with a cool West and cool Alaska, warm Great Lakes gradually becoming EC with a warm New England gradually becoming cold and expanding into the Mid-Atlantic. There is also a warm Southeast that gradually becomes EC. The pattern then morphs into a pattern that retains the cool West but refocuses it a bit more North, has a mixed Alaska and a very warm anomaly centered on Texas but including Oklahoma, Arkansas and parts of New Mexico and Louisiana plus a small Northeast warm anomaly. To be "warm" with respect to anomalies means warmer than usual for this time of year and "cool" with respect to anomalies means cooler than usual for this time of the year. The graphic shows the level of probability of being different from EC.
Given that it is hard to even describe the above sequence, one wonders what the chances are that it will happen as shown in the maps.
Now - Precipitation
Here is the three-month DJF Precipitation Outlook issued on November 17, 2016 :
And here is the Early Precipitation Outlook for December Issued on November 17, 2016
6 - 10 Day Precipitation Outlook Issued Today
8 - 14 Day Precipitation Outlook Issued Today
Looking further out.
As I view these maps (which are very different than the maps produced by the unsupervised computers on Sunday) on Monday November 28 (two of the five update each day and one (the Week 3 - 4 Outlook) updates every Friday, it looks like precipitation for December 4 to December 12 will begin with Alaska mostly dry, California to Missouri dry or EC, and pretty much the rest of CONUS wet which will first evolve into a Northern Tier wet and parts of the Southern Tier dry pattern and then morph into a pattern of mostly EC with a mostly dry Alaska, a wet anomaly centered on Montana and a dry Southeast Quadrant. Again, this is more of an ENSO Neutral Pattern than a La Nina Pattern. When discussing anomalies, "wet" means wetter than usual for this time of the year and "dry" means drier than usual for this time of the year. The graphic shows the level of probability of being different from EC.
The above sequence of transitions seems a bit less complicated than the projected sequence for temperature.
Here is the NOAA discussion released today November 28, 2016
6-10 DAY OUTLOOK FOR DEC 04 - 08 2016
THE AVAILABLE MODELS EXHIBIT GOOD AGREEMENT ON THE PREDICTED 500-HPA HEIGHT PATTERN. RIDGING AND ABOVE NORMAL HEIGHTS ARE PREDICTED OVER THE BERING STRAIT AND WESTERN ALASKA, WITH TROUGHING AND BELOW NORMAL HEIGHTS FROM WESTERN CANADA TO THE SOUTHWEST CONUS TO THE MISSISSIPPI VALLEY. THE FLOW EAST OF THE MISSISSIPPI IS COMPRISED OF RIDGING OVER THE SOUTHEAST WITH FAST, PROGRESSIVE FLOW OVER THE NORTHEAST. DISAGREEMENT IN THE MODEL SOLUTIONS ARE EVIDENT OVER THE GREAT LAKES, WHERE THE CANADIAN ENSEMBLE MEAN AND THE 12Z GFS HAVE ABOVE NORMAL HEIGHTS, WHILE OTHER ENSEMBLE MEAN CHARTS DEPICT NEAR TO BELOW NORMAL HEIGHTS. MODELS WITH THE HIGHEST 500-HPA HEIGHTS OVER THE GREAT LAKES AND SOUTHEAST CANADA HAD HIGHER ANALOG CORRELATIONS, INDICATING A HISTORICAL PREFERENCE FOR THAT PATTERN. THE RESULTING UPPER-LEVEL PATTERN HAS ABOVE NORMAL HEIGHTS FOR MOST OF MAINLAND ALASKA, BELOW NORMAL HEIGHTS FROM THE WEST COAST TO THE MISSISSIPPI VALLEY, AND NEAR NORMAL HEIGHTS ALONG THE APPALACHIANS.
THE UPPER LEVEL AND LOWER LEVEL FLOW PATTERNS FAVOR BELOW NORMAL TEMPERATURES FOR MOST OF ALASKA, EXCEPT THE ALEUTIANS, AND FROM THE NORTHWEST AND NORTHERN ROCKIES TO THE SOUTHERN GREAT PLAINS. ABOVE NORMAL TEMPERATURES UNDER PROGRESSIVE FLOW ARE FAVORED FOR THE GREAT LAKES AND NORTHEAST, WHILE THE SUBTROPICAL RIDGING OVER THE SOUTHEAST FAVORS ABOVE NORMAL TEMPERATURES.
RIDGING OVER MUCH OF ALASKA FAVORS BELOW MEDIAN PRECIPITATION, WHILE THE TROUGHING OVER THE WESTERN CONUS FAVORS AN ACTIVE STORM TRACK ACROSS THE NORTHERN CONUS. SOUTH OF THE MAIN STORM TRACK OVER THE NORTHERN CONUS, BELOW MEDIAN PRECIPITATION IS FAVORED FROM CALIFORNIA TO NEW MEXICO TO KANSAS. PROGRESSIVE FLOW AND A STRONG JET OVER THE EASTERN CONUS IMPLIES A LOWER-LEVEL BAROCLINIC ZONE, WHICH FAVORS ABOVE NORMAL PRECIPITATION OVER THE INTERIOR SOUTHEAST, NORTH OF THE SUBTROPICAL RIDGE.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD OVERALL AGREEMENT AMONG THE VARIOUS MODELS AND TOOLS, AND GENERALLY LOW TO MODERATE SPREAD AMONG THE ENSEMBLE MEMBERS
8-14 DAY OUTLOOK FOR DEC 06 - 12 2016
THE PREDICTED 500-HPA HEIGHT PATTERN IN WEEK-2 IS SIMILAR TO THAT PREDICTED FOR 6-10 DAY PERIOD. MODEL AGREEMENT REMAINS GOOD, ALTHOUGH SOME DIFFERENCES ARE EVIDENT IN THE RAISING OF HEIGHTS OVER THE SOUTHEAST, WITH THE GFS AND CANADIAN MODELS RAISING HEIGHTS MORE QUICKLY.
PREDICTED RIDGING OVER ALASKA IS LIKELY TO BE CENTERED FURTHER NORTH, CONTINUING TO FAVOR BELOW MEDIAN PRECIPITATION FOR MOST OF ALASKA AND BELOW NORMAL TEMPERATURES FOR CENTRAL AND EASTERN ALASKA. MEAN TROUGHING, CENTERED OVER THE NORTHWEST, FAVORS THE CONTINUATION OF AN ACTIVE STORM TRACK FROM THE PACIFIC NORTHWEST TO THE GREAT LAKES. THIS ALSO FAVORS BELOW NORMAL TEMPERATURES FROM THE WEST COAST TO THE CENTRAL AND NORTHERN GREAT PLAINS. THE BAROCLINIC ZONE FORECAST IN 6-10 DAYS OVER THE EASTERN CONUS IS EXPECTED TO MODERATE, AND UPPER-LEVEL TROUGHING OVER THE SOUTHERN GREAT PLAINS IS PREDICTED TO LESSEN BY WEEK-2, SO BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE SOUTHERN TIER OF THE CONUS.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODELS BUT TEMPERED BY LARGE CHANGES FROM YESTERDAY, LIKELY ROOTED IN SMALLER SCALE VARIABILITY.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON DECEMBER 15
Some might find this analysis interesting as the organization which prepares it focuses on the Pacific Ocean and looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of ENSO events.
Analogs to the Outlook.
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 regularly analyzing this second set of information. The first set which is what I am using today applies to the 5 and 7 day observed pattern prior to today. The second set, which I am not using, relates to the correlation of the forecasted outlook 6 - 10 days out with similar patterns that have occurred in the past during the dates covered by the 6 - 10 Day Outlook. The second set of analogs may also be useful information but they put the first set of analogs in the discussion with the second set available by a link so I am assuming that the first set of analogs is the most meaningful and I find it so.
Nov 18, 1961
Nov 19, 1961
Nov 7, 1964
Nov 26, 1981
Dec 9, 1992
Dec 10, 1992
Nov 10, 1994
Probably a Modoki
Nov 11, 1994
Probably a Modoki
Dec 10, 1999
Following the MegaNino
Nov 16, 2003
(t) = a month where the Ocean Cycle Index has just changed or does change the following month.
One thing that jumped out at me right away was the spread among the analogs from November 7 to December 10 which is 33 days which is as not as tight as last week. I have not calculated the centroid of this distribution which would be the better way to look at things but the midpoint, which is a lot easier to calculate, is about November 23 quite similar to last week. These analogs are centered on 3 days and 4 days ago (November 24 or 25). So the analogs could be considered slightly in advance meaning that we will be getting weather that normally would occur at about this time of year or a couple of days later than usual.
There are two El Nino Analogs (why are there any?), two La Nina Analogs and six ENSO Neutral Analogs. The phase of the ocean cycles in the analogs point weakly towards all the McCabe Conditions except C(see table below). McCabe Conditions A, B, and D have some similarity to the forecast pattern through December 23 because of all the changes that take place during that period.
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. One of the major reasons that I write this weather and climate column is to encourage a more long-term and World view of weather.
Very Little Drought. Southern Tier and Northern Tier from Dakotas East Wet
More wet than dry but Great Plains Dry
Northern Tier and Mid-Atlantic Drought
Southwest Drought extending to the North and also the Great Lakes
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.
Recent CONUS Weather
This is provided mainly to see the pattern in the weather that has occurred in recent months. Because it is now November, I have removed the July, August, and September Graphics.
Here is the 30 Days ending November 19, 2016
.Temperature pattern is similar but the East Coast warm anomaly is reduced. Precipitation pattern change is dramatic with the Northwest wetness gone and the Southeast Drought intensified. Remember this is a 30 day average with the seven most distant days removed and seven more recent days added so it usually changes slowly but not this week
And the 30 Days ending November 26, 2016
.The temperature pattern has not changed much but soon will. The drought pattern in the West has eased a bit.
B. Beyond Alaska and CONUS Let's Look at the World which of Course also includes Alaska and CONUS
World Weather Forecast produced by the Australian Bureau of Meteorology. Unfortunately I do not know how to extract the control panel and embed it into my report so that you could use the tool within my report. But if you visit it Click Here you will be able to use the tool to view temperature or many other things for THE WORLD. It can forecast out for a week. Pretty cool. Return to this report by using the "Back Arrow" usually found top left corner of your screen to the left o the URL Box. It may require hitting it a few times depending on how deep you are into the BOM tool.
Although I can not display the interactive control panel in my article, I can display any of the graphics it provides so below are the current worldwide precipitation and temperature forecasts for three days out. They will auto-update and be current for Day 3 whenever you view them. If you want the forecast for a different day Click Here
Notice how wet Brazil will be.
Looking Out a Few Months
This is the precipitation forecast from Queensland Australia.
It is kind of amazing that you can make a worldwide forecast based on just one parameter the SOI and changes in the SOI. Notice that the FALLING SOI triggers a different pattern of wet and dry than we showed last week. Recently, we ran a weather column with the Title El Nino or La Nina? The point of that article was simply that ENSO is not solid La Nina at this point. We are getting mixed signals. This project may be based on a mixed signal but it also is based on the lag between the SOI and weather impacts so it may be valid even if the SOI begins to increase now.
Here is the JAMSTEC three month Temperature Forecast.
It is mostly warm but with notable cool areas in Northern Brazil, Australia, and Greenland and Mongolia.
And here is the three month JAMSTEC Precipitation Forecast.
Of interest is the wet Brazil and dry Maritime Continent and parts of Southeast Asia.
And then to get more focus, I extracted and enlarged an image for Europe on the left and CONUS on the right.
For many purposes 55N latitude is the dividing line in Europe in regards to the Arctic Oscillation (AO) and the North Atlantic Oscillation (NAO) Impacts. You see that here with Scandinavia wet and southern Europe dry. It is suggestive of AO+. The NAO is highly correlated with the AO so it is also suggestive of NAO +. For CONUS it is a La Nina pattern but different than shown below for NOAA and it is not a North/South divide.
There is a short JAMSTEC discussion that relates the seasonal outlook to their El Nino and El Nino Modoki forecasts and this was issued on Tuesday November 22, so here it is:
Nov. 23, 2016 Prediction from 1st Nov., 2016
According to the SINTEX-F prediction, the current La Niña Modoki/La Niña state will continue until spring. [Editor's Note: They explain what they mean by this being a Modoki rather than a true La Nina in a very long detailed explanation which focuses on the Modoki aspects of this Cool Event. We will discuss that next Monday but the simple explanation is that the cool anomaly is not well connected to the coast of South America]. That state will then start decaying and the tropical Pacific will return to a normal state by summer. The model prediction appears to be consistent so far with the observed evolution of the sea surface temperature (SST) anomalies
Indian Ocean forecast:
The negative Indian Ocean Dipole will keep decaying and disappear in winter. The Ningaloo Nino will appear off the west coast of Australia in late austral summer and persist until late austral fall.
On a seasonal scale, most part of the globe will experience a warmer-than-normal condition, while some parts of northern Brazil, Australia, and Mongolia will experience a colder-than-normal condition in the boreal winter.
According to the seasonally averaged rainfall prediction, most parts of southern China, southeastern Africa, southern Europe, and eastern/western U.S. will experience a drier condition during boreal winter, while most parts of Brazil, western Central Africa, and South Africa will experience a wetter-than-normal condition. Australia will receive above normal rainfall during austral summer. Northern parts of Japan (including Hokkaido) will be cooler and drier than normal while southern parts of Japan will generally be warmer than normal in winter. However, we note that fluctuating mid- and -high latitude climate in winter may not be captured well by the current model.
Additional forecasts from JAMSTEC including future time periods can be found at this link.
Sea Surface Temperature (SST) Departures from Normal for this Time of the Year i.e. Anomalies
My focus here is sea surface temperature anomalies as they are one of the two largest factors determining weather around the World.
And when we look at the current Sea Surface anomalies below, we see a lot of them not just along the Equator related to ENSO.
Remember this discussion is all about anomalies not absolute temperatures...so it is deviation from seasonal norms.
The waters north and east of Japan remain very cool as are the waters southwest of Kamchatka Siberia, The Central Indian Ocean is now basically IOD Neutral. The waters off the Southern Coast of Australia are cool but the East Coast is slightly warm. Water north of Australia is slightly warm but less so than one would expect with La Nina. The waters southeast of Africa are cool. To the west, south of the Gulf of Guinea the water is warm.
The overall Northern Pacific no longer looks to be PDO Positive (the horseshoe pattern with the cool anomaly inside the horseshoe shape there) mostly because of the lack of warm water east and south of the cool water. But the cool anomaly is growing. The NOAA Pacific Decadal Oscillation (PDO) Index as reported by NOAA (Washington University also reports the PDO but using a different methodology which results in higher index numbers) has been 2016-January 0.79, 2016- February 1.23, 2016- March 1.55, 2016- April 1.59. 2016- May 1.40, 2016-June 0.76, 2016-July 0.12, 2016-August-0.90, 2016- September -1.09, 2016- October -0.88. The above would make the PDO now NEGATIVE but may becoming less NEGATIVE. Here is the list of PDO values.
The waters west of CONUS are now slightly warm but only very close to land. The Gulf of California is warm but the area involved is reduced from last week. Further north, the Gulf of Alaska is quite warm with the Bering Straits also warm.
The Black Sea is neutral and the Caspian Sea is now cool. The Mediterranean is warm.
The water directly west of South America is not showing much of a strong La Nina pattern. There is a narrow cool anomaly in the Pacific right along the Equator in the La Nina Measurement Area. Recently it has appeared to be a bit more robust. We are told that the MJO is not significant right now but for a while it appeared to have moved the cool pool to the east as would occur with the Active Phase of the MJO. But now it extends west much like a Modoki. The water off the West Coast of Central America is quite warm.
The U.S. Great Lakes are warm. The North Atlantic is warm. North of Scandinavia and to the east is it is very warm. The Northern Gulf of Mexico is warm. The waters north of Antarctica East of South America are now much less cooler even compared to last week which is a big change.
I have some additional commentary on this static analysis of the anomalies below where I examine the four-week change in these anomalies. The list of Atlantic Multidecadal Oscillation (AMO) values can be found here.
Since these are "departures" or "anomalies", it is not a seasonal pattern that is being shown it is the changes from what we would expect on a seasonal basis. It is important to understand that and interpret my comments above in the context of anomalies not absolute temperatures.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
Comparing a four-week graphic to a prior four-week graphic is always tricky since only 25% of the data has changed and I am not showing the former graphic (it is in last week's report). I add the new one to my draft report, compare and comment on the change and then delete the old one to keep this report to a manageable size. Also it is important to recognize that what you see in this graphic is the change in the anomaly over the last four weeks. So blue means either cooler or less warm. Red means warmer or less cool. So you have to refer to the graphic above this one to really interpret this graphic as what we are seeing here is the change in the anomalies. What we see in this graphic is four weeks of change not the current absolute anomalies which are shown in the above graphic. It is not derivatives in the mathematical sense but deltas. They are somewhat similar. The graphic above this one has no time component. It is simply the deviation from climatology and this graphic below shows the four week change in the deviation from climatology. So it is a bit like the first (graphic above) and second (graphic below) derivatives but not exactly. I take it a step further by comparing this week's version of the graphic to the prior week and report on the differences below.
What I see as I look at both last week's version of this graphic and the current one (before deleting the prior version) is this week is a continuation of the warming (less La Nina-ish) trend along the Eastern Equatorial Pacific except right off the Coast of Ecuador. The Pacific cooling trend north of 40N is less intense. There has been no change to the cooling trend south of Australia. Remember we are talking about changes in the anomalies something like a second derivative so you have to refer to the graphic above this one to know if blue is cool or less warm and if red is warm or less cool.
Look at the Western Pacific in Motion.`
The above graphic which I believe covers the area from the Dateline west to 100E and from the Equator north to 45N normally shows the movement of tropical storms towards Asia in the lower latitudes (Trade Winds) and the return of storms towards CONUS in the mid-latitudes (Prevailing Westerlies). This is recent data in motion (last 24 hours) not a forecast. But it provides a pretty good idea of what is heading towards Southeast Asia and the Maritime Continent. It also shows what is headed back towards CONUS. Information on Western Pacific storms can be found here. This is an unofficial private source but one that is easy to read.
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 November 22, 2016 Version and looking at Week 2 of that forecast.
Mostly I see for Week Two (this graphic updates on Tuesdays and I post on Monday which is almost a week later so Week Two applies unless I go back on Tuesday and update the discussion when the map updates), the period November 30, 2016 to December 6, 2016, it will likely be wet and stormy south of Mainland Asia including the Western part of the Maritime Continent.
C. Progress of the Cool ENSO Event
A major driver of weather is Surface Ocean Temperatures. Evaporation only occurs from the Surface of Water. So we are very interested in the temperatures of water especially when these temperatures deviate from seasonal norms thus creating an anomaly. The geographical distribution of the anomalies is very important.
To a substantial extent, the temperature anomalies along the Equator have disproportionate impact on weather so we study them intensely and that is what the ENSO (El Nino - Southern Oscillation) cycle is all about.
Subsurface water can be thought of as the future surface temperatures. They may have only indirect impacts on current weather but they have major impacts on future weather by changing the temperature of the water surface.
Winds and Convection (evaporation forming clouds) is weather and is a result of the Phases of ENSO and also a feedback loop that perpetuates the current Phase of ENSO or changes it. That is why we monitor winds and convection along or near the Equator especially the Equator in the Eastern Pacific.
Starting with Surface Conditions.
TAO/TRITON GRAPHIC (a good way of viewing data related to the part of the Equator and the waters close to the Equator in the Eastern Pacific where we monitor to determining the current phase of ENSO. It is probably not necessary to follow the discussion below, but here is a link to TAO/TRITON terminology.
I have deleted many of the TAO/TRITON graphics we looked at when we were watching El Nino develop and decline. But I saved this one which was close to the maximum. It was not the maximum but it was the one that I froze which was the closest to the maximum that I saved. It is useful for comparing the current situation with the pattern that prevailed near the peak of the El Nino this past winter. Since most of my graphics auto-update, in order to be able to view a prior version of a particular graphic, I "freeze it" by basically cut and paste to a graphics file and then embed that "frozen graphic" in my article.
And here is the current version of the TAO/TRITON Graphic.
The above should be compared to the bottom part of the following graphic. Notice the pattern is remarkably similar. The difference is that in January, the anomaly was a warm anomaly stretching from 130W to 160W and now it is a cool anomaly. When it was a warm anomaly, it was a 3C anomaly in the center ring. Now the center ring is a -0.5C anomaly. So this is opposite to last winter but the intensity is a third or less of the situation last winter.
Location Bar for Nino 3.4 Area Above and Below
I have not provided here the information needed to assess the shift in the cool pool to the east and now south but it is certainly dramatic.
The below table which only looks at the Equator shows the extent of anomalies along the Equator. I had split the table to show warm, neutral, and cool anomalies. The top rows showed El Nino anomalies. When there were no more El Nino anomalies along the Equator, I eliminated those rows. The two rows just below that break point contribute to ENSO Neutral and after another break, the rows are associated with La Nina conditions. I have changed the reference date to May 23, 1016.
Comparing Now to May 23, 2016
Subareas of the Anomaly
Degrees of Coverage
As of Today
May 23, 2016
As of Today
May 23 2016
As of 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*
0C or cooler Anomaly
These Rows Show the Extent of the La Nina Impacts on the Equator
-0.5C or cooler
-1C or cooler Anomaly
-1.5C or cooler Anomaly
If you just look on the Equator, there are 50 degrees of Longitude of Neutral to La Nina anomalies which is the maximum possible as the ONI Measurement Area is 50 degrees of Longitude wide and that also is the maximum possible since the ENSO Measurement Area only stretches for 50 degrees. There are today only 30 degrees of water anomalies cool enough to be a La Nina. Subtracting 30 degrees from the 50 degrees you end up with 20 degrees of ENSO Neutral and 30 degrees of water cool enough to qualify as La Nina i.e. temperature anomalies more negative than -0.5C. There are today 0 degrees of water along the Equator in the ONI Measurement that is -1C or less which would be cool enough to be a moderate La Nina when just looking at the Equator and there are 0 degrees of -1.5C water. The ONI Measurement Area extends 5 degrees of Latitude North and South of the Equator so the above table is just a guide and a way of tracking the changes. Away from the Equator it is generally warmer when a La Nina is trying to get started. The water from 3N to 5N and from 3S to 5S had until recently remained relatively warm especially west of 150W. But now the cool anomaly is fairly well distributed within the Nino 3.4 Measurement Area but the cooler water below is not reaching the surface rapidly and is slowly dissipating.
I calculate the current value of the ONI index (really the value of NINO 3.4 as the ONI is not reported as a daily value) each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W Nino 3.4 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 November 28, in the afternoon working from the November 27 TAO/TRITON report, this is what I calculated. [Although the TAO/TRITON Graphic appears to update once a day, in reality it updates more frequently.]
Calculation of ONI from TAO/TRITON Graphic
A. 170W to 160W
B. 160W to 150W
C. 150W to 140W
D. 140W to 130W
E. 130W to 120W
Total divided by five subregions i.e. the ONI
(-2.2)5 = -0.4
(-0.6)/5 = -0.1)
My estimate of the daily Nino 3.4 SST anomaly has become much less negative at -0.1 which is an ENSO Neutral value. NOAA has again reported the weekly ONI to be ENSO Neutral at -0.4. This week our estimates are very different.
Nino 4.0 is reported as being the same as last week at -0.3. Nino 3 is being reported the same -0.3. Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is now more negative at -0.3 which is a change from last week. Last week was an even larger cooling. What is left of this Cool Event is now focused on the Eastern Pacific.
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 table form but going back a couple of more years can be found here.
This is from a legacy "frozen" NOAA system meaning it is maintained but not updated. It seems to show a cycle in the Nino 3.4 Index Values. I see that as I monitor the TAO/TRITON graphic. My best guess is that it is related to the MJO but it certainly is intriguing.
Sea Surface Temperature and Anomalies
It is the ocean surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. So we are interested in the actual ocean surface temperatures and the departure from seasonal normal temperatures which is called "departures" or "anomalies". Since warm water facilitates evaporation which results in cloud convection, the pattern of SST anomalies suggests how the weather pattern east of the anomalies will be different than normal.
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 snapshots of the conditions at different points in time. This Hovmoeller provides a good way to visually see the evolution of this ENSO event. I have decided to use the prettied-up version that comes out on Mondays rather that the version that auto-updates daily because the SST Departures on the Equator do not change rapidly and the prettied-up version is so much easier to read. You can see that the cool anomaly (bottom of the Hovmoeller is vanishing right before our eyes with almost no blue, more white and now some yellow. This graphic explains to a large extent the small week to week changes in the Nino 3.4 Index Reading. Remember the +5, -5 degree strip around the Equator that is being reported in this graphic. So it is the surface but not just the Equator.
The Cool Event sure looks like it has peaked and is in decline. There are now other reasons to believe it is not temporary but the decline phase of this quasi-La Nina Modoki.
In recent weeks I have stopped showing the below graphic which is more focused on the Equator but looks down to 300 meters rather than just being the surface. There has until this week been almost no change from the prior week but over the last month there has been sufficient change to warrant including this graphic this week.
NOAA has now dashed-in the upwelling phase of the multiple Kelvin Waves that has created this pseudo-La Nina and you can see that it is playing out just as NOAA upgrades the status of this Cool Event. It is pretty clear that this cool event has peaked and is in the decline phase. It is a disgrace. You can even see what might become a downwelling Kelvin Wave that will settle the matter.
Let us look in more detail at the Subsurface Water Temperatures.
Equatorial Subsurface Analysis
We are now going to change the way we look at a three-dimensional view of the Equator and move from the surface view and an average of the subsurface heat content to a more detailed view from the surface down.
Current Sub-Surface Conditions. Notice by the date of the graphic (dated November 24, 2016) that the lag in getting this information posted so the current situation may be a bit different than shown although this graphic was updated today so it is more current than usual. The date shown is the midpoint of a five-day period with that date as the center of the five-day period.
And now the pair of graphics that I regularly provide.
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. At different times and today in particular, I have discussed the difference between the actual values and the deviation of the actual values from what is defined as current climatology (which adjusts every ten years) and how both measures are useful but for different purposes.
The top graphic shows surface temperature anomalies. The coolest water at the surface shows up only in very small non-connected areas. Water of La Nina coolness but not very intense shows up along the Equator from Dateline to the Coast of Ecuador but with significant gaps of less cool water. The -1C water shows most strongly east of the Nino 3.4 Measurement Area and only very sporadically between 170W to 120W. Notice that the cool anomaly in excess of -1C no longer exists within the Nino 3.4 Measurement Area and appears to be rotating to towards the coast and diminishing in size.. How is this cool event to be sustained?
Notice the warm water at depth west of 165E. We also see some warm water below the cool anomaly. It is not a Kelvin Wave but may be a sign of things to come.
The bottom half of the graphic (Absolute Values which highlights the Thermocline) is now more useful as we track the progress of this new Cool Event.
It shows the thermocline between warm and cool water. The 28C Isotherm is again located close to the Dateline. This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm has perhaps shifted back a bit to 170W so we do not have ideal conditions for significant convection along the Equator east of the Dateline which is a characteristic of a Cool Event. Notice the steepness of the 28C, 27C and 26C Isotherms but they are less steep than recently especially the 26C Isotherm. The 25C isotherm remains at 150W. The 20C Isotherm has moved close to the surface but is not reaching the surface this week except perhaps at 90W. It is clearly a transition state and all of this is important not just for tracking this cool event but thinking about when the next El Nino might be triggered. This graphic helps understand the logic behind some of the forecasts of the Nino 3.4 Index. So it is still a battle going on with La Nina nudging ahead but not looking like it can sustain itself. It should peak soon.
It is why the models are having a hard time figuring out if this it a real deal La Nina or simply a Cool Event that comes close to being a La Nina. They should catch up with the human eye shortly.
Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.
Although I did not fully discuss the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures which remains relevant. What we have is only the upwelling phase of the series of Kelvin waves last winter.
There is cool water from 170W to the coast of Ecuador. But the coolest water, however, is only reaching the surface in the Nino 3.4 Measurement Area in two very small areas one very small at around 160W and another slightly larger from about 145W to 135W which is much less than last week. The cooler than -1C anomaly no longer exists in the Nino 3.4 Measurement Area. So there is not much chance of the Nino 3.4 readings rising dramatically any time soon. And there is warmer water under the cool anomaly. The coolest water is over to the east where La Nina is not measured by NOAA. This is probably not the best place to express the thought but this way of measuring an ENSO event leaves a lot to be desired. Only the surface interacts with the atmosphere and is able to influence weather. The subsurface tells us how long the surface will remain cool (or warm). Anomalies are deviations from "Normal". NOAA calculates and determines what is "Normal" which changes due to long ocean cycles and Global Warming. So to some extent, the system is "rigged". Hopefully it is rigged to assist in providing improved weather forecasts. But to assume that any numbers reported can be assumed to be accurate to a high level of precision is foolhardy. It is strange to me that the Asian forecasting services generally conclude that that this cool ENSO Phase is not a La Nina but a near La Nina and NOAA concludes it is a La Nina but they express it in percentages. It is the same ocean. The reported readings are very close but the Asian readings are generally just slightly higher (less La Nina-ish) than the NOAA reading and their cut-off points for declaring a La Nina are a bit different and the parts of the Equator they look at are a bit different. It might be explained by what part of the ENSO pattern impacts their area of geography but it just seems to me that NOAA is a bit over eager. And I wonder why.
And now Let us look at the Atmosphere.
Low-Level Wind Anomalies near the Equator
Here are the low-level wind anomalies.
The Easterlies (the blue) are suddenly again no longer there in the Eastern Pacific probably because of MJO action. I know there is no acknowledged MJO right now but there are diminished Easterlies as if there was an active phase of the MJO right now in the Eastern Pacific. There are Easterlies in the Central Pacific.
And now the Outgoing Longwave Radiation Anomalies which tells us where convection has been taking place.
In the above graphic, the area of convection at about 120E has spread out with a gap in between the two wet areas.
And Now the Air Pressure which Shows up Mostly in an Index called the SOI.
This index provides an easy way to assess the location of and the relative strength of the Convection (Low Pressure) and the Subsidence (High Pressure) near the Equator. Experience shows that the extent to which the Atmospheric Air Pressure at Tahiti exceeds the Atmospheric Pressure at Darwin Australia when normalized is substantially correlated with the Precipitation Pattern of the entire World.
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.
90 Day Average
The 30-day average, which is the most widely used measure, as of November 28is reported at -0.29 which is less negative (i.e. less El Nino-ish) than last week. The 90-day average at +3.37 is almost unchanged from last week. 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 disparity between the two is one reason why we look at both. (Sustained values over +7 are usually associated with La Nina and less than -7 are usually associated with El Nino). To some extent it is the change in the SOI that is of most importance. It had been increasing but may now be stabilizing or going down. That could change but for now the SOI is not signaling a La Nina but ENSO Neutral.
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. November has not been particularly favorable for La Nina development and most likely neither will be December in terms of the MJO.The forecasts of the MJO are all over the place and not suggesting a strong Active or Inactive Phase of the MJO any time soon.The MJO being Inactive is more favorable for La Nina than the MJO being Active. But the MJO goes back and forth from being Active, Inactive, strong and weak so it has mostly a short-term impact. It is possible that a weak Inactive Phase of the MJO might give this dying La Nina a little reprieve. .
Lately, the impact has been fairly muted. But the change in the SOI recently and some other changes suggest that we are having an Active Phase of the MJO even if such is not being reported and what we have is not the MJO but something else that is impacting the cool pool in a similar way as an Active MJO would. The forecast for the MJO is updated weekly and can be found here. If the MJO is not in its Active Phase then perhaps some other pattern is impacting the SOI and also shifting the cool pool to the east. We are also having a non-split fairly strong Jet Stream which is also consistent with an Active MJO. So I am calling it a Stealth MJO.
The MJO tends to be more important when the situation is ENSO Neutral and the MJO can start the process of an El Nino getting started. It is less significant re the initiation of a La Nina but is a factor. It is surprising how weak the MJO has been for months. But it may account for what seems like a cycling of the estimate of Nino 3.4 as the cool water is blown first to the west and then to the east. This impacts the upwelling also.
Forecasting the Evolution of ENSO
The below is first the early-month report from CPC/IRI which I call the reading of the tea leaves.in that it is based on a combination of model results and a survey of the views of meteorologists. Recently the early month analysis has been more favorable for a la Nina than the later in the month model-based analysis.I think meteorologists like action so they prefer either El Nino or La Nina to Neutral. But the models are dispassionate about it.
And now we have the more recent fully model-based version .
There is not a lot of difference but the preference for La Nina conditions in NDJ is a bit less than a week earlier when the report was based mainly on a survey of meteorologist. When I see DJF I notice that January is the middle month in the DJF three-month period. Thus it seems that January is probably the last month that will have Nino 3.4 values equal to or under -0.5. When I look at the slightly higher probability for Nino 3.4 to be -0.5 or less as compared to Nino 3.4 to be in the Neutral Range, I am not blown away by the probability that we will be in La Nina condition into 2017..We are now past mid-November so to me the story-line should be the imminent end of the Cool Event rather than upgrading the Status of the Cool Event.
Here is the daily PDF and Spread Corrected version of the NOAA CFSv2 Forecast Model.
Notice the forecast is for the Nino 3.4 anomaly to become less cool i.e. less La Nina-ish very soon. If the forecasts turn out to be correct, we are near or at at the peak of the Cool Event now and that adds to the perplexity of NOAA recently upgrading the status of this Cool Event. Perhaps they should work like pollsters and have some additional categories such as leans La Nina or leans El Nino.
Here is the Nino 3.4 report from the Australian BOM (it updates every two weeks)
Negative Indian Ocean Dipole ends, while central tropical Pacific Ocean warms
The Indian Ocean Dipole has returned to neutral levels, after being in a negative phase since May. The tropical Pacific Ocean remains El Niño–Southern Oscillation (ENSO) neutral.
In the tropical Pacific, most indicators of ENSO are well within neutral bounds. In the past fortnight, sea surface temperatures in the central tropical Pacific Ocean have warmed once again, further dampening chances of La Niña. The Southern Oscillation Index (SOI) has been negative since late October (La Niña values are typically positive) but remains neutral. Trade winds are currently close to average. Only cloudiness near the Date Line continues to show some La Niña-like characteristics.
Climate models predict the tropical Pacific Ocean will remain cooler than average, but in the ENSO-neutral range, through until the end of the 2016–17 summer. Only one of the eight models surveyed indicates La Niña for the summer months. A La Niña developing this late in the calendar year has only occurred once since 1980.
The Indian Ocean Dipole (IOD) has returned to neutral levels as the monsoon trough transitions to the southern hemisphere. This shift changes the wind patterns over the tropical Indian Ocean, breaking down the typical IOD circulation. The strong negative IOD event helped drive Australia's wettest May–September period in 117 years of record. The July IOD value was equal-strongest for at least 50 years.
We also now have the most recent JAMSTEC November 1 ENSO forecast.
The model continues to show ENSO Neutral for the next two years (after what they call a weak La Nina Modoki ends). But the potential for an El Nino has been taken out of the forecast. The JAMSTEC Discussion has just become available and is shown earlier in this report. They tend to publish their Nino 3.4 forecast and the World Maps for temperature, precipitation and other topics before they publish the ENSO Index discussion.
Indian Ocean IOD (It updates every two weeks)
The IOD Forecast:is indirectly related to ENSO but in a complex way.
The negative Indian Ocean Dipole (IOD) event has concluded. The weekly index value to 20 November was −0.26 °C. This marks the fourth week the index value has been within neutral values.
IOD events typically decay during spring, and the influence of the IOD on Australian climate is weak during the months December to May. This is because the monsoon trough shifts south over the tropical Indian Ocean changing wind patterns, which prevents the IOD pattern from being able to form.
However, the continued presence of much warmer than average water to the northwest of Australia may see continued influence on Australia, including enhanced rainfall.
D. Putting it all Together.
According to some of the models, it seems likely to have La Nina conditions or even be declared to have been a full La Nina. But Australia and Japan do not see it that way and are not calling for a True La Nina at this point in time. So NOAA is a bit the Odd Man Out but it is mostly a question of degree and in the end NOAA may turn out to have been correct. NOAA is calling for a borderline La Nina and the others are forecasting a La Nina-ish event that does not quite meet the criteria for being labeled a La Nina and does not last long enough to meet the criteria.
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.
The odds of a climate shift for CONUS taking place has significantly increased. It may be in progress. It looks like it will require one more La Nina or ENSO Neutral event and this appears to be the way this might unfold. The AMO is pretty much neutral at this point (but more positive i.e. warm than I had expected) so it may need to become a bit more negative for the McCabe A pattern to become established. That seems to be slow to happen so I am thinking we need at least a couple more years for that to happen.
From Atlantic to Pacific: a first in hurricane naming
Tropical Storm Otto is the first storm on record to carry the same name while moving from the North Atlantic to the Northeast Pacific or vice versa. In all such prior events, NHC policy was to assign a different name when an identifiable tropical cyclone moved from one basin to another. NHC’s subsequent name-retention policy was adopted more than a decade ago, but Otto is the first storm to put the rule into practice. Under the old rule, five tropical storms or hurricanes--including the most recent, Hurricane Cesar-Douglas (1996)--underwent a name change when moving from Atlantic to Pacific or vice versa. A few other “crossover” tropical cyclones have been recorded, most of them moving from Atlantic to Pacific rather than vice versa. Some of these were no more than a tropical depression in one or the other basin, which meant that only one name was used during the entire life cycle. The most recent of these was Hermine (2010), which formed as an East Pacific tropical depression before entering the western Gulf and striking the northeast coast of Mexico as a tropical storm.
As part of the new naming convention, Otto in the East Pacific has been assigned a different ID than Otto in the Atlantic under the U.S. Automated Tropical Cyclone Forecasting System (ATCF), even though the storm has the same name and is considered the same cyclone in both basins. This is playing havoc with various online platforms that map and archive tropical cyclones. At the National Hurricane Center’s website, and on our own site, you’ll see a Hurricane Otto in the Atlantic and a Tropical Storm Otto in the Pacific depicted as two separate tropical cyclones. It appears that the two life stages of Otto will be considered separately when calculating storm totals and Accumulated Cyclone Energy for the 2016 Atlantic and East Pacific seasons.
Weather Research in the News
Global Warming in the News
Antarctic Ice Not Shrinking Could it be that the geography impacts how that process works? Antarctica is land surrounded by open water and the Arctic is water surrounded by land?
I posted it sometime back but I have still not had the time to fully digest and analyze this very important report. So I am carrying it forward.
An important issue is the validity of RCP 8.5 as a benchmark. Here is a good article on that. It has page after page of comments so here may be a shorter version with somewhat fewer comments.
I need to really thoroughly review this very important article and that will take some time. But here are some initial thoughts.
I did want to mention that under the McCabe et al analysis, one of the four combinations of ocean phases was a drought phase so that suggested that for approximately 25% of the time the chances of drought were very good. Thus one would have expected a significant drought once a century. So that is not new information.
McCabe et al also calculated a change in the situation due to Warming. That is not new information either.
So although this new analysis is more recent than the older analysis which was just after the PDO and AMO were figured out, to me it is not very different. The main difference is this paper has scenarios for the future. One probably could have developed them from the McCabe et al analysis. And they are talking about 35 year droughts which is not all that different from the droughts we have had once per century. My quick reading of the article did not come across the mention of El Nino. Are they in the analysis? I need to read more.
The authors make things simple with basically 2C, 4C, and 6C scenarios. How the 2C is defined is important. Apparently it is mean warming from 2051 to 2100 compared to 1951 to 2000. I like to use simple approaches so my mind I will think about it as 2075 compared to 1975. There are other papers that use a different way of measuring 2C (and 4C and 6C). Some
go back to 1750 or the beginning of the Industrial Revolution. Well if 1975 is the base even if the growth rate is steeper then linear there is still some room to get to 2C. We are about 40 years into the 100 year period used by the authors.
More when I have had a chance to really study this important paper.
The below is the key graphic:
F. Table of Contents for Page II of this Report Which Provides a lot of Background Information on Weather and Climate Science
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.
G. Table of Contents of Contents for Page 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.
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.
J FM 1951
ONI Recent History
The official reading for Jul/Aug/Sept has now been increased to -0.6.The JAS reading was the first La Nina Value. The Aug/Sept/Oct reading has now been issued and is currently listed as -0.7. So there would now need for there to be three more periods of -0.5 or colder for this to be eligible to be formally recorded as a La Nina. NOAA seems to be determined to make that happen. THEIR FUNDING MAY DEPEND ON THAT.
The full history of the ONI readings can be found here. The MEI index readings can be found here.
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