November 14, 2016 Weather and Climate Report – Can One Campaign for La Nina?

Written by Sig Silber

NOAA on November 10, issued this Advisory:  La Nina Conditions exist. This November 10 post on Climate.gov from the person who prematurely declared there to be an El Nino in the Winter of 2014/2015 is clearly the trigger for the issuance of this NOAA Advisory. The use of the term “La Nina Conditions” is kind of a sleight of hand. 

“La Nina Conditions” is a combination of an assessment of current conditions with an expectation that such conditions will prevail for a while. It is not a declaration that a La Nina Event occurred as that can only happen after the fact. So it is a lot like reporting half-time football scores as final scores. Then there is the question of the value of such a declaration. It does not in any way impact weather forecasts. I doubt that it changes how public safety and related agencies operate. I suspect those with the most interest in that declaration were commodity traders and that is what bothers me about it.

I want to be clear. It is not that one could not reasonably conclude that La Nina Conditions prevail. For me it is the question of why change the status of this Cool Event now. The SOI is not confirming that we have a true La Nina. The Nino 3.4 readings are marginal for a La Nina, have been more indicative of a La Nina prior to now, and are forecast to slowly increase  i.e. move towards ENSO Neutral. So it is almost as if the thinking was that “if we do not upgrade the La Nina Status right now, we will not be able to justify doing so two weeks from now.” That bothers me a bit.

A specific problem with the analysis by Emily Becker relates to her flow chart.

I think the correct answer to that question in her decision tree is clearly “No”. Her use of the word “several” is problematic as “several” generally means at least four and that certainly is not what she meant. The models suggest that Nino 3.4 will remain less than -0.5C through January. This is November so that is not even several months. So, to me, it was clearly a stretch.

Here is a another perspective on this matter

Of great interest is the question of how one detects ENSO signals in a world where oceans are warming. NOAA is diligent about updating their baseline along the Equator every five years. But that may not be sufficient to be able to identify ENSO states since although the anomalies along the Equator are the metrics used to identify the two extremes phases of ENSO: El Nino and La Nina, ENSO is more that just what is going on along the Equator in the Pacific Ocean. So this makes me a bit more sympathetic to this issuance of an upgrade.

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 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 previously reported on the October 20 NOAA 15 Month Forecast and compared their 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 publish a new 15 Month Update Report shortly after November 17, 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.

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.

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 only by clicking on Three Day or  Four Day or Five Day or Day Six or Day Seven

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. This week we do not see the 540 line thinking about entering CONUS. Remember that 540 relates to sea level. Inland from the Northwest you re above sea level so snow is likely.     

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. Notice

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. 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. Tina does not appear to be a threat to CONUS but there may be a more significant storm next week. There is an area of interest in the Caribbean just off of Costa Rica and it is not clear what if anything might develop from that situation. 

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.

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 NDJ 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. 

First – Temperature

Here is the Three-Month NDJ Temperature Outlook issued on October 20, 2016:

Here is the Updated Temperature Outlook for November which was issued on October 31, 2016

 6 – 10 Day Temperature Outlook

8 – 14 Day Temperature Outlook   

Looking further out.

Now – Precipitation 

Here is the three-month NDJ Precipitation Outlook issued on October 20, 2016 :

And here is the Updated  Outlook for November Precipitation Issued on October 31, 2016

6 – 10 Day Precipitation Outlook

8 – 14 Day Precipitation Outlook 

Looking further out.

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Here is the NOAA discussion released today November 14, 2016

6-10 DAY OUTLOOK FOR NOV 20 – 24 2016  

TODAY’S NUMERICAL MODEL SOLUTIONS ARE IN FAIR AGREEMENT ON THE 500-HPA FLOW  PATTERN PREDICTED OVER THE FORECAST DOMAIN. THE OFFICIAL BLENDED HEIGHT PATTERN  FEATURES TROUGHS OFF THE WEST COAST AND OVER THE NORTHEASTERN CONUS. A RIDGE IS FORECAST OVER THE WESTERN CONUS AND WESTERN CANADA. BELOW NORMAL HEIGHTS ARE  FORECAST FOR THE WEST COAST, EASTERN THIRD OF THE CONUS AND SOUTHERN ALASKA, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE PREDICTED FOR THE REMAINDER OF THE CONUS AND NORTHERN ALASKA. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE SMALL TO MODERATE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. THE GREATEST WEIGHT WAS GIVEN TO THE GFS SUPERENSEMBLE MEAN BASED ON CONSIDERATIONS OF RECENT SKILL AND  ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.

BELOW NORMAL HEIGHTS AND TROUGHING OVER THE NORTHEASTERN CONUS TILT THE ODDS FOR BELOW NORMAL TEMPERATURES FOR MOST OF THE EASTERN CONUS. POSITIVE 500-HPA HEIGHT ANOMALIES AND RIDGING ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND WESTERN CONUS AS WELL AS MAINE. ABOVE NORMAL TEMPERATURES ARE MOST FAVORED FOR THE SOUTHWEST, WHERE TEMPERATURE TOOLS ARE IN THE BEST AGREEMENT. NEAR TO ABOVE NORMAL TEMPERATURES ARE FAVORED FOR ALASKA, WHICH IS CONSISTENT WITH CALIBRATED REFORECAST TEMPERATURE TOOLS FROM GFS ENSEMBLE FORECASTS. 

 ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE WESTERN CONUS AHEAD OF A TROUGH PREDICTED OVER THE EASTERN PACIFIC. THERE ARE ENHANCED PROBABILITIES FOR ABOVE MEDIAN PRECIPITATION FOR THE NORTHEAST IN ASSOCIATION WITH THE TROUGH OVER THE NORTHEASTERN CONUS. POSITIVE 500-HPA HEIGHT ANOMALIES AND RIDGING ENHANCE PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR THE CENTRAL CONUS. BELOW MEDIAN PRECIPITATION IS FAVORED FOR MOST OF THE EASTERN CONUS IN ASSOCIATION WITH PREDICTED SURFACE HIGH PRESSURE. PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS FAVOR BELOW MEDIAN PRECIPITATION FOR MUCH OF ALASKA.

 FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIR AGREEMENT AMONG THE MODELS AND TOOLS.

8-14 DAY OUTLOOK FOR NOV 22 – 28 2016 

TODAY’S ENSEMBLE MEAN DYNAMICAL MODEL FORECASTS ARE IN FAIR AGREEMENT ON THE PREDICTED 500-HPA CIRCULATION PATTERN OVER NORTH AMERICA FOR THE WEEK-2 PERIOD. TROUGHS ARE FORECAST OFF THE WEST COAST AND NEAR THE NORTHEASTERN CONUS, WHILE  RIDGING IS PREDICTED OVER THE NORTHERN ROCKIES AND WESTERN CANADA. TODAY’S 500-HPA BLEND CHART DEPICTS BELOW NORMAL HEIGHTS FOR THE WEST COAST, EASTERN THIRD OF THE EASTERN CONUS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE FORECAST FOR THE REMAINDER OF THE CONUS. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE TO LARGE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. THE GREATEST WEIGHT WAS GIVEN TO THE EUROPEAN ENSEMBLE MEAN BASED ON CONSIDERATIONS OF RECENT SKILL AND ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.

BELOW NORMAL HEIGHTS AND TROUGHING NEAR THE NORTHEASTERN CONUS TILT THE ODDS FOR BELOW NORMAL TEMPERATURES FOR MUCH OF THE EASTERN CONUS. POSITIVE 500-HPA HEIGHT ANOMALIES AND RIDGING ENHANCE PROBABILITIES FOR NEAR TO ABOVE NORMAL TEMPERATURES FOR THE CENTRAL AND WESTERN CONUS.  ABOVE NORMAL TEMPERATURES ARE FAVORED FOR ALASKA, WHICH IS CONSISTENT WITH CALIBRATED REFORECAST TEMPERATURE TOOLS FROM GFS ENSEMBLE FORECASTS. 

ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE WESTERN CONUS, PARTS OF THE CENTRAL PLAINS AND THE MIDDLE MISSISSIPPI VALLEY AHEAD OF A TROUGH PREDICTED OVER THE EASTERN PACIFIC. POSITIVE 500-HPA HEIGHT ANOMALIES AND RIDGING ENHANCE PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR THE NORTHERN ROCKIES AND EASTERN ALASKA. PRECIPITATION ESTIMATES FROM THE GEFS AND ECMWF ENSEMBLE MEMBERS FAVOR BELOW MEDIAN PRECIPITATION FOR THE EAST COAST AND GULF COAST STATES.

FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIR AGREEMENT AMONG THE MODELS AND TOOLS.

THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON NOVEMBER 17

I think this article is also relevant.

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.

(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 October 30 to November 18 which is only 19 days which is a fairly tight spread. 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 9. These analogs are centered on 3 days and 4 days ago (November 10 or 11). 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 the Fall/Winter.

For more information on Analogs see discussion in the GEI Weather Page Glossary.

There are three El Nino Analogs (why are there any?), just one La Nina Analog (truly strange but consistent with the Aleutian Low situation), and five ENSO Neutral Analogs. The phase of the ocean cycles in the analogs points strongly towards McCabe Condition A. This is somewhat consistent with the 6 – 14 Day Outlook. . 

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.

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 5, 2016

And the 30 Days ending November 12, 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 hitting your “backspace” key which 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

This is the precipitation forecast from Queensland Australia.

JAMSTEC issued their Precipitation Forecast recently based on the October 1, 2016 ENSO analysis. Notice this forecast is for December 2016 through February 2017.

Here I just focused on Europe and CONUS

Here is the temperature forecast

There is a discussion that goes with it:. .

Oct. 17, 2016

Prediction from 1st Oct., 2016

ENSO forecast:

According to the SINTEX-F prediction, the current weak La Niña Modoki will start decaying and the tropical Pacific will return to a normal state by boreal spring. 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 start decaying and disappear in boreal winter. A positive Indian Ocean Dipole may evolve in early summer of 2017. However, it is still uncertain at the present stage.

Regional forecast:

In boreal winter, as a seasonally averaged view, most part of the globe will experience a warmer-than-normal condition, while some parts of Brazil, northern Europe, and northern Australia will experience a colder-than-normal condition.

According to the seasonally averaged rainfall prediction, eastern China, Indo-China, East Africa, most parts of Europe, U.S. and the Far East (including Japan) might experience a drier condition during boreal fall, while most parts of Brazil, southern West Africa, western Central Africa, and South Africa will experience a wetter-than-normal condition. Australia will receive above normal rainfall during austral summer. Most parts of Japan will experience above normal temperature and below normal precipitation (less snowfall) in winter. Those may be associated with a warm Indian Ocean and a weak La Niña Modoki in the Pacific.

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.

Look at the Western Pacific in Motion.`

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 8, 2016 Version and looking at Week 2 of that forecast.

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.

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.

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 14, in the afternoon working from the November 13 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.]

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.

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..

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 9, 2016) that the lag in getting this information posted so the current situation may be a bit different than shown. 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 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.

The 30-day average, which is the most widely used measure, as of November 14 is reported at -2.38 which is less negative (i.e. less El Nino-ish)  than last week. The 90-day average at +5.13 is essentially 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. October was not particularly favorable for La Nina development and most likely neither will be November 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.

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 Late October CPC/IRI fully Model-Based Forecast issued on October 20, 2016 followed by the new forecast issued on November 10 which is based on a combination of model results and views of meteorologists. There should not be a big difference between the first and second forecasts in each month  (presumably for the early forecast, the meteorologists consult their models in addition to reading tea leaves) but it is a difference and recently a huge one. I assume they do it this way as to avoid forcing meteorologists to have to run their computers twice a month (some sarcasm expressed there). I call the Early Forecast the “Reading of the Tea Leaves” Forecast as I do not have a lot of respect for it.

So first we have the previously released late-month Model-Based version.

And then the early-month reading of the tea leaves.which is based on a combination of model results and 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.

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

Some La Niña indicators strengthen; negative IOD nears end

The tropical Pacific Ocean remains El Niño–Southern Oscillation (ENSO) neutral, while the negative Indian Ocean Dipole (IOD) has continued to decay over the past fortnight, and is likely to be near its end.

In the tropical Pacific, some indicators such as cloudiness near the Date Line show La Niña-like characteristics, whereas sea surface temperatures (SSTs) in the central tropical Pacific Ocean and the Southern Oscillation Index (SOI) remain at neutral levels. Recent strengthening of the trade winds in the western tropical Pacific brings the potential for some further cooling of ocean waters. However, this strengthening is likely the result of a Madden–Julian Oscillation (MJO) pulse. Trade winds are likely to weaken in the coming weeks as the MJO passes. Hence it does not appear that the tropical Pacific atmosphere and ocean are currently reinforcing each other, as they would during the developing stages of a La Niña.

Most climate models predict the tropical Pacific Ocean will remain cooler than average, but ENSO-neutral, through until the end of the 2016–17 summer. Only one of eight models suggests the Pacific may briefly reach weak La Niña levels towards the end of 2016. A La Niña developing this late in the calendar year has only occurred once since 1980.

Warmer than average sea surface temperatures to Australia’s north suggest that some La Niña-like impacts may occur, even if an event does not fully develop.

The negative IOD event, in place since late May, has weakened over the past fortnight. The monsoon trough has begun to move southward over the IOD region, which changes the wind patterns. This change means the negative IOD event is near its end, and this is supported by model outlooks. Both a negative IOD and La Niña typically contribute to increased rainfall in spring for eastern and central Australia.

We also now have the most recent JAMSTEC October 1 ENSO forecast.

The model continues to show ENSO Neutral for the next two years.

Indian Ocean IOD (It updates every two weeks)

Not directly related to ENSO is the IOD Forecast:

Discussion

Indian Ocean Dipole outlooks

The negative Indian Ocean Dipole (IOD) event is drawing to a close. The weekly index value to 6 November was −0.30 °C. This marks the second week the index value has failed to exceed the threshold for a negative IOD event.

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.

Information on the impact of a negative IOD on Australia can be found here.

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 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.

Nothing has changed in the past month so one wonders why NOAA felt compelled to issue a highly questionable change in the status of this Cool Event. It has zero impact on how weather forecasts are made. It equates to changing the wording from “possible but not sure” to “not sure but possible”. It provides zero additional information to most users of weather forecasts other than commodity traders.

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

Southwest Mega-drought Risk – This article  is important and needs to be read carefully.

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.

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.

1. Introduction

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.

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.