Written by Sig Silber
JAMSTEC suggests that there may be a Climate Shift in the Pacific to PDO Positive. That is big news. The news arrived too late to fully cover the implications this week but we will next week.
From the JAMSTEC discussion which was just posted last night:
Interestingly, majority of the ensemble members indicate recurrence of a moderate El Niño event in the latter half of 2017. It will be interesting if an El Niño event really evolves in 2017, which may suggest a decadal turnabout in the tropical Pacific climate condition to El Niño-like state after a long spell of La Niña-like state, which led to the global warming hiatus.
Now some housekeeping information. Working on a Glossary of Terms but right now it is only partially operational. It will be possible increasingly 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 December 15 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 January 19, 2017. 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.
A. Focus on Alaska and CONUS (all U.S. except Hawaii)
First Let us 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.
Image credit: Center for Western Weather and Water Extremes, Scripps/UCSD. More explanation can be found at Atmospheric Rivers (Click to read full Weather Underground Dr. Bob Henson article)
To turn the above into a forecasting tool click here and you will have a dashboard for a short-term forecasting model.
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.
You can enlarge the below daily (days 3 – 7) weather maps for CONUS by clicking on Day 3 or Day 4 or Day 5 or Day 6 or Day 7. These maps auto-update so whenever you click on them they will be forecast maps for the number of days in the future shown.
Here is the seven-day precipitation forecast. More information is available here.
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.
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. When I published, this graphic was not being displayed but the NOAA website indicated that was a temporary outage. However you can obtain somewhat similar imagery by clicking here. It actually provides more functionality than the current displayed (when it works) version but you have to click to get it as I have not figured out how to get it to display otherwise. It is really cool imagery and explains a lot.
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.
Below is the current water vapor Imagery for North America.
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.
Now looking at the 5 Day Forecast
.
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.
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 although I do not have a lot of confidence in it), the Updated Outlook for the single month of January, 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 December 15, 2016:
Here is the “Early” Temperature Outlook for January Issued on December 15, 2016
6 – 10 Day Temperature Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on December 19 was 3 out of 5)
8 – 14 Day Temperature Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on December 19 was 3 out of 5)
Looking further out.
December 25 to January 2 | December 31 to January 13 |
Alaska will become cool, CONUS East warm and the West cool with the warm anomaly gradually displacing the Western cool anomaly otherwise know as retrograding. But this is less intense than shown yesterday. | The expansion of the East Coast warm anomaly does not extend as far west in the Week 3 – 4 Forecast but the West Coast cool anomaly retreats into the Northwest. |
Remember the Week 3-4 Experimental Outlook was issued last Friday and I am looking at the 6 – 10 and 8 – 14 day forecasts issued today i.e. Monday. So that explains the overlap of dates. Remember that the Week 3 – 4 Forecast covers two weeks so it can appear to not mesh perfectly but actually do so over that two-week period. At this point it meshes pretty well. |
Now – Precipitation
Here is the three-month DJF Precipitation Outlook issued on November 17, 2016 that I do not have much confidence in.
And here is the Updated Precipitation Outlook for December Issued on November 30, 2016
6 – 10 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on December 19 was 3 out of 5)
Unlink
8 – 14 Day Precipitation Outlook Issued Today (Note the NOAA Level of Confidence in the Forecast Released on December 19 was 3 out of 5)
Looking further out.
.
December 25 to January 2 | December 31 to January 13 2017 |
Alaska is mostly wet. CONUS starts mostly wet with only Florida dry and gradually develops a dry anomaly from New Mexico north to Montana/North Dakota. | Only Western Alaska is wet extending down to the Northwest, the Southeast is dry and there is a small dry anomaly centered on North Dakota and a larger Mississippi Valley wet anomaly reaching to Chicago. |
Remember the Week 3 – 4 Experimental Outlook was issued last Friday and I am doing this analysis on Monday which explains the overlap in dates. |
Here is the NOAA discussion released today December 19, 2016
6-10 DAY OUTLOOK FOR DEC 25 – 29 2016
TODAY’S NUMERICAL MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE 500-HPA FLOW PATTERN PREDICTED OVER THE FORECAST DOMAIN. A BROAD TROUGH IS FORECAST OVER THE WESTERN CONUS, WHILE A STRONG RIDGE IS ANTICIPATED OVER THE EAST-CENTRAL PACIFIC. TODAY’S 500-HPA BLEND CHART DEPICTS ABOVE NORMAL HEIGHTS ACROSS THE EASTERN HALF OF THE CONUS, PARTS OF THE CENTRAL AND SOUTHERN PLAINS, AND THE ALEUTIANS, WHILE BELOW NORMAL HEIGHTS ARE FORECAST OVER MOST OF THE REMAINDER OF THE CONUS AND ALASKA. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE SPREAD ACROSS THE CENTRAL AND EASTERN CONUS, WITH MODERATE TO LARGE SPREAD SEEN FOR THE SOUTHWESTERN CONUS AND SOUTHEASTERN PACIFIC. THE GREATEST WEIGHT FOR THE BLENDED HEIGHT FORECAST WAS GIVEN TO THE 0Z ECMWF ENSEMBLE MEAN SOLUTION BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.
ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR MOST OF THE EASTERN HALF OF THE CONUS, AND PARTS OF THE CENTRAL AND SOUTHERN PLAINS. NEAR TO BELOW NORMAL HEIGHTS TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES FOR MUCH OF THE WESTERN HALF OF THE CONUS. ABOVE NORMAL SEA SURFACE TEMPERATURES ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF WESTERN ALASKA AND THE ALEUTIANS.
THE BROAD TROUGH FORECAST OVER THE WESTERN CONUS AND AN ASSOCIATED FRONTAL SYSTEM FAVOR ABOVE MEDIAN PRECIPITATION FOR MOST OF THE CENTRAL AND EASTERN CONUS. THE EXCEPTION IS OVER THE SOUTHEAST WHERE ABOVE NORMAL HEIGHTS TILT THE ODDS TO NEAR TO BELOW MEDIAN PRECIPITATION. BELOW NORMAL HEIGHTS FAVOR ABOVE MEDIAN PRECIPITATION FOR THE WESTERN CONUS, WESTERN ALASKA, AND ALASKA PANHANDLE CONSISTENT WITH PRECIPITATION ESTIMATES FROM THE GEFS ENSEMBLE MEMBERS.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODEL SOLUTIONS OFFSET BY FAIR AGREEMENT AMONG THE VARIOUS TOOLS.
8-14 DAY OUTLOOK FOR DEC 27, 2016 – JAN 02, 2017
TODAY’S ENSEMBLE MEAN DYNAMICAL MODEL FORECASTS ARE IN GOOD AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER NORTH AMERICA FOR THE WEEK-2 PERIOD. A BROAD TROUGH IS FORECAST TO DOMINATE MUCH OF THE CONUS, WHILE A STRONG RIDGE IS ANTICIPATED OVER THE EAST-CENTRAL PACIFIC. TODAY’S 500-HPA BLEND CHART DEPICTS ABOVE NORMAL HEIGHTS ACROSS THE EASTERN HALF OF THE CONUS, PARTS OF THE CENTRAL AND SOUTHERN PLAINS, SOUTHWESTERN MAINLAND ALASKA, AND THE ALEUTIANS, WHILE BELOW NORMAL HEIGHTS ARE FORECAST OVER MOST OF THE REMAINDER OF THE CONUS AND ALASKA. THE GREATEST WEIGHT FOR THE BLENDED HEIGHT FORECAST WAS GIVEN TO THE 0Z ECMWF ENSEMBLE MEAN SOLUTION BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.
THE EXPECTED TEMPERATURE ANOMALY PATTERN FOR WEEK-2 IS QUITE SIMILAR TO THAT FORECAST FOR THE 6-10 DAY PERIOD. ABOVE NORMAL HEIGHTS ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR MOST OF THE EASTERN HALF OF THE CONUS, AND MUCH OF THE CENTRAL AND SOUTHERN PLAINS. NEAR TO BELOW NORMAL HEIGHTS TILT THE ODDS TO NEAR TO BELOW NORMAL TEMPERATURES FOR MUCH OF THE WESTERN HALF OF THE CONUS AND ALASKA. ABOVE NORMAL SEA SURFACE TEMPERATURES ENHANCE PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR PARTS OF WESTERN ALASKA AND THE WESTERN ALEUTIANS.
THE BROAD TROUGH FORECAST OVER THE CONUS FAVORS NEAR TO ABOVE MEDIAN PRECIPITATION FOR MOST OF THE EASTERN HALF OF THE CONUS. BELOW NORMAL HEIGHTS FAVOR ABOVE MEDIAN PRECIPITATION FOR THE WESTERN CONUS, NORTHERN ALASKA, AND ALASKA PANHANDLE. PRECIPITATION ESTIMATES FROM THE GEFS ENSEMBLE MEMBERS FAVOR BELOW MEDIAN PRECIPITATION FOR PARTS OF THE GREAT PLAINS AND SOUTH-CENTRAL ALASKA.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO GOOD AGREEMENT AMONG THE MODEL SOLUTIONS OFFSET BY FAIR AGREEMENT AMONG THE VARIOUS TOOLS.
Some might find this analysis click to read 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.
Day | ENSO Phase | PDO | AMO | Other Comments |
Dec 27, 1953 | Neutral | – | + | |
Dec 30, 1971 | La Nina | – | – | |
Dec 15, 1975 | La Nina | – | – | |
Dec 9, 1976 | El Nino | + | – | |
Nov 30, 1978 | Neutral | – | – | |
Dec 1, 1978 | Neutral | – | – | |
Dec 31, 1985 | La Nina | + | – | |
Dec 4, 1991 | El Nino | + | – | El Nino Modoki Type I and Type II |
Dec 3, 2004 | El Nino | -(t) | + | El Nino Modoki Type II |
(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 30 to December 31 which is 31 days which is much less than 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 December 15. These analogs are centered on 3 days and 4 days ago (December 14 or December 15). So the analogs could be considered in sync with the calendar meaning that we will be getting weather that normally would occur at about this time of year.
For more information on Analogs see discussion in the GEI Weather Page Glossary.
There are three El Nino Analogs (why are there any), three La Nina Analogs and three ENSO Neutral Analogs. Looks like the analogs are suggesting that ENSO Neutral Conditions prevail. The phase of the ocean cycles in the analogs points strongly towards McCabe Conditions A and B which are opposites. The forecast does not start out one way and then change dramatically so my conclusion is that the level of confidence NOAA has in their forecast may be and overestimate.
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.
McCabe Condition | Main Characteristics |
A | Very Little Drought. Southern Tier and Northern Tier from Dakotas East Wet |
B | More wet than dry but Great Plains Dry |
C | Northern Tier and Mid-Atlantic Drought |
D | 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 recently.
Here is the 30 Days ending December 10, 2016
And the 30 Days ending December 17, 2016
B. Beyond Alaska and CONUS Let’s Look at the World which of Course also includes Alaska and CONUS
Near Term
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
Precipitation
Temperature
Looking Out a Few Months
The new precipitation forecast from Queensland Australia was based on rapidly rising SOI. That did not seem to be correct.
So I used the feature to create a forecast based on stable SOI and this is what was generated.
Here is the most recent JAMSTEC three-month Temperature Forecast.
And here is the most recent three month JAMSTEC Precipitation Forecast.
And then to get more focus, I extracted and enlarged an image for CONUS on the left and Europe on the right.
There is a short but very important JAMSTEC discussion:
Dec. 19, 2016 Prediction from 1st Dec., 2016
ENSO forecast:
According to the SINTEX-F prediction, the current La Niña Modoki/La Niña state will continue until late winter. Interestingly, majority of the ensemble members indicate recurrence of a moderate El Niño event in the latter half of 2017. It will be interesting if an El Niño event really evolves in 2017, which may suggest a decadal turnabout in the tropical Pacific climate condition to El Niño-like state after a long spell of La Niña-like state, which led to the global warming hiatus.
Indian Ocean forecast:
The negative Indian Ocean Dipole has started decaying and will be terminated by the end of 2016. Then we expect a positive Indian Ocean Dipole in summer of 2017. We also expect the Ningaloo Niño off the west coast of Australia in late austral summer, which may persist until late austral fall. However, the prediction plumes are spreading and those expectations are still uncertain at the present stage.
Regional forecast:
On a seasonal scale, most part of the globe will experience a warmer-than-normal condition, while some parts of northern U.S., southern Canada, northern Brazil, and Australia will experience a colder-than-normal condition in the boreal winter.
According to the seasonally averaged rainfall prediction, most parts of southeastern China, Indonesia, eastern Africa, eastern half of Europe including Italy, and Caribbean countries including Florida will experience a drier condition during winter, whereas the Philippines, the eastern U.S., and the western part of Europe will experience a wetter-than-normal condition. Most parts of Brazil, Australia and South Africa will experience a wetter-than-normal condition during austral summer. Most parts of Japan will be warmer and quite drier than normal in winter. However, we note that highly 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
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.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
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 December 13, 2016 Version and looking at Week 2 of that forecast.
Look at the Western Pacific in Motion. NOAA is having problems with their web site but you can find a somewhat similar version by clicking here. It actually provides more functionality than the displayed version but you have to click to get it as I have not figured out how to get it to display otherwise.
C. Progress of the Cool ENSO Event
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.
And here is the current version of the TAO/TRITON Graphic.
———————————————— | A | B | C | D | E | —————– |
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.
Subareas of the Anomaly | Westward Extension | Eastward Extension | Degrees of Coverage | |||||
As of Today | May 23, 2016 | As of Today | May 23 2016 | As of Today | In Nino 3.4 | Dec 12, 2016 | May 23, 2016 | |
These Rows Show the Extent of ENSO Neutral Impacts on the Equator | ||||||||
0.5C or cooler Anomaly* | 170E | 155E | Land | 155W | 95 | 50 | 95 | 50 |
0C or cooler Anomaly | DATELINE | 155W | LAND | Land | 85 | 50 | 85 | 60 |
These Rows Show the Extent of the La Nina Impacts on the Equator | ||||||||
-0.5C or cooler | 170W125W | 145W | 148WLAND | Land | 52 | 27 | 65 | 50 |
-1C or cooler Anomaly | 115W | 140W | LAND | 105W | 20 | 0 | 40 | 35 |
-1.5C or cooler Anomaly | LAND | 135W | LAND | 120W | 0 | 0 | 0 | 0 |
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 December 19, in the afternoon working from the December 18 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.]
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | +0.3 | -0.5 |
B. 160W to 150W | +0.1 | -0.5 |
C. 150W to 140W | -0.1 | -0.3 |
D. 140W to 130W | -0.8 | -0.2 |
E. 130W to 120W | -1.0 | -0.3 |
Total | -1.5 | -1.8 |
Total divided by five subregions i.e. the ONI | (-1.5)5 = -0.3 | (-1.8)/5 = -0.4 |
From Tropical Tidbits.com
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.
I had stopped showing the below graphic which is more focused on the Equator but looks down to 300 meters rather than just being the surface. But over the last month there has been sufficient change to warrant including this graphic.
Let us look in more detail at the Equatorial Water Temperatures.
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. Notice by the date of the graphic (dated December 14, 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 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 except along the Equator where it is adjusted every five years) and how both measures are useful but for different purposes.
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.
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.
And now Let us look at the Atmosphere.
Low-Level Wind Anomalies near the Equator
Here are the low-level wind anomalies.
And now the Outgoing Longwave Radiation Anomalies which tells us where convection has been taking place.
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.
Date | Current Reading | 30-Day Average | 90 Day Average |
Dec 13 | -2.91 | -0.77 | +1.41 |
Dec 14 | -2.96 | -0.80 | +1.15 |
Dec 15 | -7.37 | -0.44 | +0.89 |
Dec 16 | -5.97 | +0.28 | +0.62 |
Dec 17 | +0.88 | +1.12 | +0.47 |
Dec 18 | +5.40 | +1.70 | +0.40 |
Dec 19 | +5.29 | +1.75 | +0.28 |
The 30-day average, which is the most widely used measure, as of December 19 is reported at +1.75 which is up from last week but remains an ENSO Neutral Value. The 90-day average at +0.28 is down from last week and again solidly Neutral. 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 in September but now in October and November and through half of December has stabilized in the Neutral Range. 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 was not 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 be giving this dying La Nina a little reprieve but the forecast is that this will soon change to a weak Active Phase so it is not very significant other than on a weekly basis. .
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
We have the December 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.
Figure 1 is based on a consensus of CPC and IRI forecasters, in association with the official CPC/IRI ENSO Diagnostic Discussion
Now we have the December 15, 2016 fully model-based version .
And here is the discussion that was released with the graphic.
What is the outlook for the ENSO status going forward? The most recent official diagnosis and outlook was issued one week ago in the NOAA/Climate Prediction Center ENSO Diagnostic Discussion, produced jointly by CPC and IRI; it carries a La Niña advisory and called for weak La Niña to last through winter 2016-17 (i.e., for December-February), and for a transition to neutral to occur by late winter. The latest set of model ENSO predictions, from mid-December, now available in the IRI/CPC ENSO prediction plume, is discussed below. Those predictions suggest that the SST could remain in the weak La Niña category during the rest of 2016 and into the early part of 2017, or may return to neutral by the New Year.
As of mid-November, 17% of the dynamical or statistical models predicts La Niña conditions for the initial Dec-Feb 2016-17 season, while 83% predict neutral ENSO. At lead times of 3 or more months into the future, statistical and dynamical models that incorporate information about the ocean’s observed subsurface thermal structure generally exhibit higher predictive skill than those that do not. For the Mar-May 2017 season, among models that do use subsurface temperature information, no model predicts La Niña conditions, 89% predicts ENSO-neutral conditions, and 11% predicts El Niño conditions. For all model types, the probabilities for La Niña are 9% for Jan-Mar 2016-17, and less than 5% for all subsequent seasons out to Aug-Oct 2017. The probability for neutral conditions is at least 70% for all seasons through the final season of Aug-Oct 2017, and rise to greater than 90% from Jan-Mar through Apr-Jun 2017. Probabilities for El Niño are near zero initially, rise to 5-10% by Mar-May 2017, and to 25-30% from Jun-Aug through the final season of Aug-Oct.
Here is the daily PDF and Spread Corrected version of the NOAA CFSv2 Forecast Model.
The full list of weekly values can be found here.
Forecasts from Other Meteorological Agencies.
Here is the Nino 3.4 report from the Australian BOM (it updates every two weeks)
Discussion (notice their threshold criteria are different from NOAA but also their actuals are higher than recorded by NOAA and yet Nino 3.4 is standard. So someone is incorrect OR WORSE.)
Here is the discussion.
ENSO outlooks
Outlooks from the eight international climate models surveyed by the Bureau indicate that neutral ENSO conditions are likely for the remainder of the southern hemisphere summer.
One model continues to indicate an increased likelihood of the central tropical Pacific Ocean briefly exceeding La Niña thresholds before warming. All models indicate warming of the central Pacific is likely over the coming months.
Most models maintain neutral outlooks through to May 2017; however one model suggests strong warming may be possible in autumn, reaching El Niño thresholds in May. It must be noted that this outlook straddles the autumn predictability barrier—typically the ENSO transition period—during which most models have their lowest forecast accuracy.
We also have the most recent JAMSTEC December 1, 2016 ENSO forecast.
The model continues to show ENSO Neutral or what they call a weak La Nina Modoki gradually ending. The potential for an El Nino had been taken out of the forecast last month but is back in the forecast again. The JAMSTEC Discussion is shown earlier in this report.
Indian Ocean IOD (It updates every two weeks)
The IOD Forecast is indirectly related to ENSO but in a complex way.
Discussion
Indian Ocean Dipole outlooks
The Indian Ocean Dipole (IOD) is neutral. The weekly index value to 18 December was −0.23 °C.
The influence of the IOD on Australian climate is weak during the months of December to April. This is because the monsoon trough shifts south over the tropical Indian Ocean changing wind patterns, which prevents an IOD pattern from being able to form.
However, the continued presence of much warmer than average water to the north and northwest of Australia may see continued influence on Australia, including enhanced rainfall
D. Putting it all Together.
Looks like this Cool Event is no longer even properly described as La Nina Conditions Apply.
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.
E. Relevant Recent Articles and Reports
Weather in the News
Nothing to report
Weather Research in the News
Nothing to report.
Global Warming in the News
Nothing to report
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.
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.
4. Computer Models and Methodologies
5. Reserved for a Future Topic (Possibly Predictable Economic Impacts)
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.
2. Climate Impacts of Global Warming
3. Economic Impacts of Global Warming
4. Reports from Around the World on Impacts of Global Warming
Useful Background Information
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 |
ONI Recent History
The Aug/Sept/Oct reading has been issued and is currently listed as -0.7. The Sep/Oct/Nov preliminary estimate is -0.8 so there would now need for there to be two more periods of -0.5 or colder for this to be eligible to be formally recorded as a La Nina. I suspect there will be one more but not two. 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.