Written by Sig Silber
It is not clear if the current ENSO Cool Event will be recorded as a La Nina, but it is very likely that the next few months will follow a pattern consistent with La Nina – except that NOAA is calling for a November “Monsoon”. If you live in CONUS or Alaska, the new maps will tell you what to expect where you live. We repeat the three-month World Maps and include some graphics that provide short-term World Forecasts. So there is something for everyone. Many of the graphics auto-update so much of this report will be current as of when you read it. There may be a stealth version of an Active MJO Phase going on and we will comment on that.
.NOAA Update of their November Outlook
We reported on the October 20 NOAA Seasonal Outlook and compared their Outlook with that of JAMSTEC in a special Update that you can get to by clicking here. NOAA has, as usual, issued an update for the month following the last day of the prior month. This update was issued today and rather than have a Special Update that covers simply the next month, we combine that report with our Regular Weekly Report and we will discuss that first by comparing the Updated Outlook for November to the Early Outlook for November issued on October 20.
Temperature
Prior Outlook Issued on October 20, 2016
Updated Outlook Issued on October 31, 2016
Precipitation
Prior Outlook Issued on October 20, 2016
Updated Precipitation Outlook Issued on October 31, 2016
Below is the discussion issued with this update.Sometimes it is useful to compare the present month outlook to the three-month outlook
30-DAY OUTLOOK DISCUSSION FOR NOVEMBER 2016
DURING THE PAST MONTH, CONDITIONS OVER THE TROPICAL PACIFIC HAVE BECOME MORE CONSISTENT WITH A DEVELOPING LA NINA EVENT. COUPLED WITH THE CONSENSUS AMONG VARIOUS DYNAMICAL AND STATISTICAL TOOLS, ODDS ARE NOW TILTED IN FAVOR OF LA NINA OVER THE COMING MONTHS. AS A RESULT, STATISTICAL GUIDANCE THAT USES ENSO AS A PREDICTOR IS STRONGLY CONSIDERED FOR THIS OUTLOOK.
MJO INDICES (CPC VELOCITY POTENTIAL AND RMM) INDICATE NO APPRECIABLE, COHERENT MJO ACTIVITY DURING THE PAST MONTH AND FORECASTS DO NOT DEPICT CLEAR, LONG TERM STRENGTHENING AT THE CURRENT TIME. THEREFORE, THE MJO DOES NOT INFLUENCE THE NOVEMBER OUTLOOK AT PRESENT.
THE NOVEMBER 2016 TEMPERATURE AND PRECIPITATION OUTLOOKS ARE PRIMARILY BASED ON CALIBRATED DYNAMICAL GUIDANCE, ALONG WITH STATISTICAL GUIDANCE THAT EMPHASIZES ENSO AND LONG-TERM TRENDS. COASTAL SST ANOMALIES ALSO PLAYED A SMALL ROLE IN THE OUTLOOK, PRIMARILY FOR AREAS NEAR ALASKA.
THE NOVEMBER TEMPERATURE OUTLOOK FAVORS ABOVE-NORMAL TEMPERATURES FOR MOST OF THE FORECAST DOMAIN. THE ENSO SIGNAL AND LONG-TERM TRENDS TOGETHER PLACE THE HIGHEST PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES OVER THE SOUTHWESTERN AND SOUTH-CENTRAL U.S. EXTENDING NORTHEASTWARD THROUGH THE UPPER MIDWEST, GREAT LAKES, AND NORTHEAST. LONG-TERM TRENDS ARE STRONG OVER ALASKA. EQUAL-CHANCES OF BELOW-, ABOVE-, AND NEAR-NORMAL TEMPERATURES IS INDICATED OVER A SMALL PORTION OF INTERIOR ALASKA, THE PACIFIC NORTHWEST, AND THE FAR SOUTHEASTERN PORTION OF THE CONUS. THE CALIBRATED GUIDANCE FROM THE NMME, INITIALIZED EARLY THIS MONTH, STRONGLY SUPPORTS THIS PATTERN. MORE RECENTLY INITIALIZED GUIDANCE FROM THE CFS FAVORS A VERY WARM SOLUTION ACROSS MOST OF NORTH AMERICA.
INTERESTINGLY, THIS PATTERN IS GENERALLY AN EXTENSION OF THE CURRENT WEEK-2 FORECAST, SUGGESTING A FAIRLY PERSISTENT PATTERN. RECENT WEEK 3/4 GUIDANCE GENERALLY SUPPORTS THE CONTINUATION OF THIS PATTERN THROUGH THE FIRST PART OF THE MONTH, THOUGH RECENT RUNS OF THE CFS AND THE ECMWF ENSEMBLES SUGGEST THAT SOME PATTERN CHANGE MAY EVOLVE DURING THE MIDDLE PORTION OF THE MONTH. INDEED, THEREIN LIES THE KEY UNCERTAINTY IN THE TEMPERATURE FORECAST. THE RECENT PATTERN HAS BEEN FAIRLY PERSISTENT OVER NORTH AMERICA, BUT AS THE SEASONAL CYCLE UNFOLDS, THE PATTERN IS EXPECTED TO EVOLVE ON LOW-FREQUENCY TIMESCALES TOWARD SOMETHING MORE AKIN TO THE LA NINA EXTRATROPICAL RESPONSE, WITH MORE SEASONABLE TEMPERATURES AND EVEN BELOW-NORMAL TEMPERATURES ACROSS PARTS OF THE NORTHERN CONUS. IN REALITY THIS CHANGE (IF IT HAPPENS) WILL OCCUR ACROSS A SERIES OF SYNOPTIC EVENTS, THE TIMING OF WHICH IS DIFFICULT TO CAPTURE IN A 0.5-MONTH LEAD MONTHLY FORECAST.
THE PRECIPITATION OUTLOOK IS BASED LARGELY ON CORRELATIONS WITH ENSO, WHICH EVEN IN NOVEMBER BEGIN TO SHOW A FAIRLY CANONICAL LA NINA PATTERN. ABOVE-MEDIAN PRECIPITATION IS FAVORED OVER THE NORTHERN ROCKIES EXTENDING TO THE PACIFIC NORTHWEST, WHILE BELOW-MEDIAN PRECIPITATION IS FAVORED ACROSS MUCH OF THE SOUTHERN TIER OF THE CONUS. THIS PATTERN IS ALSO STRONGLY SUPPORTED BY THE CALIBRATED NMME GUIDANCE AND RECENT RUNS OF THE CFS. DURING THE LAST WEEK OF OCTOBER, ABOVE-MEDIAN PRECIPITATION IS FAVORED OVER MUCH OF THE WESTERN CONUS.
HOWEVER, THERE IS LITTLE REASON TO BELIEVE THAT THIS SIGNAL WILL PERSIST OVER THE SOUTHWEST AND SOUTH-CENTRAL U.S. INTO NOVEMBER GIVEN THE LOW-FREQUENCY BACKGROUND STATE. AS WITH THE TEMPERATURE OUTLOOK, PROBABILITIES ARE MODEST ACROSS THE FORECAST DOMAIN GIVEN THE AFOREMENTIONED UNCERTAINTY.
November plus November 2016 – January 2017 Outlook
One can mentally subtract the November Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely December 2016 and January 2017. If one does that you might conclude that:
One has to keep in mind that we are now subtracting a November Map issued on October 31 from an October 20 15 three-month map so it is less reliable than the exercise we went through last week in the special Update Report. We are assuming that the three-month outlook issued on October 20 would not change if it was released today. The results in the box above might be an indication of how December and January will differ from the three-month outlook or it might alternatively indicate how the three-month outlook might be modified if issued today. So the discussion in the paragraph above this may be overruled by a conclusion that the three-month outlook is no longer correct and the updated November Outlook is a better predictor of the three-month outlook than the three-month maps issued on October 20.
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.
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 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.
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. But 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.
Below is the forecast out five days.
Now let’s look at the situation on Day 5 below. You can see the Jet Stream crossing the Northern Tier. The vectors not in the Jet Stream proper are lower velocity parts of the atmospheric circulation and the orientation of Southwest to Northeast may bring subtropical moisture into CONUS from Mexico. It does not look all the impressive but the Jet Stream is at 300 mb and the moisture inflow from the warm Gulf Stream would be a much lower elevations so we may not see it in this graphic.
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 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
.
As I view these maps on October 31 (two of the five update each day and one (the Week 3 – 4 Outlook) updates every Friday, it looks like precipitation the first half of November will be generally dry or EC except in the extreme Northwest which will be wet and in Eastern New Mexico and Western Texas where the November Surprise “Monsoon” has an impact. This will morph as we enter the period November 12 – 25 to two wet anomalies including the East Coast and a dry anomaly for the Plains States including Texas. Alaska will be mostly dry. 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.
Here is the NOAA discussion released today October 31, 2016
6-10 DAY OUTLOOK FOR NOV 06 – 10 2016
RECENT ENSEMBLE MEAN MODEL SOLUTIONS ARE IN FAIRLY GOOD AGREEMENT ON THE 500-HPA FLOW PATTERN PREDICTED OVER THE FORECAST DOMAIN. TROUGHS ARE PREDICTED BY ALL SOLUTIONS JUST OFF THE EAST COAST OF THE CONUS AND OVER WESTERN ALASKA/THE WESTERN GULF OF ALASKA, WHILE A RIDGE IS ANTICIPATED OVER THE SOUTHWEST CONUS EXTENDING NORTH-NORTHEASTWARD OVER THE INTERIOR WESTERN CONUS AND WESTERN CANADA. THERE IS SOME DISAGREEMENT ON THE POSITION AND AMPLITUDE OF A TROUGH EXPECTED TO UNDERCUT THE RIDGE PREDICTED OVER WESTERN NORTH AMERICA.
RECENT HIGH RESOLUTION SOLUTIONS FROM THE GFS AND ECMWF ARE SIGNIFICANTLY MORE AMPLIFIED WITH INDIVIDUAL SHORTWAVE FEATURES AND INDICATE AN OMEGA-LIKE BLOCK WITH TROUGHS OVER THE NORTHWEST ATLANTIC AND OVER THE HIGH PLAINS, AND AN AMPLIFIED RIDGE OVER THE INTERIOR EASTERN CONUS.
THE ENSEMBLE SPAGHETTI CHARTS INDICATE RELATIVELY LARGE SPREAD OVER MOST OF THE CONUS, AND SMALL TO MODERATE SPREAD OVER THE EAST PACIFIC. THE PNA INDEX [Editor’s Note: For more information on the PNA click here] WHICH RECENTLY HAS BEEN POSITIVE IS FORECAST TO REMAIN POSITIVE THROUGH DAY 14. THE AO INDEX WHICH RECENTLY HAS BEEN NEGATIVE IS EXPECTED TO REMAIN NEGATIVE THROUGH DAY 14. TODAY’S BLENDED HEIGHT CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS ALONG THE EAST AND GULF COASTS, AND MOST OF ALASKA, AND NEAR TO ABOVE NORMAL HEIGHTS OVER THE REMAINDER OF THE CONUS AND THE ALASKA PANHANDLE.
WITH ABOVE NORMAL HEIGHTS AND AIR OF PACIFIC ORIGIN FORECAST TO DOMINATE MOST OF THE CONUS, THERE ARE ENHANCED PROBABILITIES OF ABOVE NORMAL TEMPERATURES FOR MUCH OF THE LOWER 48 STATES. THE EXCEPTIONS ARE ALONG THE EAST COAST WHERE NEAR TO BELOW NORMAL HEIGHTS FAVORS NEAR TO BELOW NORMAL TEMPERATURES, AND OVER PARTS OF THE SOUTHERN PLAINS WHERE THE EXPECTATION OF CLOUDS AND PRECIPITATION FAVORS NEAR NORMAL TEMPERATURES. ANOMALOUS SOUTHERLY FLOW TILTS THE ODDS TO ABOVE NORMAL TEMPERATURES FOR MUCH OF CENTRAL AND EASTERN ALASKA.
ABOVE NORMAL HEIGHTS AND/OR ANOMALOUS NORTHERLY FLOW ENHANCE PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR THE EASTERN THIRD OF THE CONUS, MUCH OF THE NORTHERN TIER OF THE COUNTRY, AND THE INTERIOR WEST. TROUGH ENERGY UNDERCUTTING THE WESTERN RIDGE TILTS THE ODDS TO ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE CENTRAL AND SOUTHERN PLAINS. THE TROUGH FORECAST OVER THE WESTERN GULF OF ALASKA FAVORS ABOVE MEDIAN PRECIPITATION FOR PARTS OF THE PACIFIC NORTHWEST, SOUTH COASTAL MAINLAND ALASKA, AND THE ALASKA PANHANDLE.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: ABOUT AVERAGE, 3 OUT OF 5, DUE TO GOOD MODEL AND TOOL AGREEMENT, OFFSET BY LARGE SPREAD AMONG THE ENSEMBLE MEMBERS.
8-14 DAY OUTLOOK FOR NOV 08 – 14 2016
DURING WEEK-2, THE MEAN TROUGHS AND RIDGES IN THE 500-HPA HEIGHT PATTERN ARE FORECAST TO SHIFT A BIT WESTWARD. THIS IS CAUSED BY THE TROUGH ENERGY FORECAST TO UNDERCUT THE WESTERN RIDGE, PHASING WITH THE TROUGH OFF THE EAST COAST, AND LEADING TO RETROGRESSION OF THE MAIN TROUGH AXIS. THE ENSEMBLE SPAGHETTI DIAGRAMS CONTINUE TO INDICATE RELATIVELY LARGE SPREAD OVER THE CONUS, ALTHOUGH THERE SEEMS TO BE RELATIVELY GOOD AGREEMENT ON THE TROUGH PREDICTED OVER THE EASTERN CONUS. TODAY’S BLENDED HEIGHT CHART INDICATES NEAR TO BELOW NORMAL HEIGHTS OVER THE EASTERN THIRD OF THE CONUS, PARTS OF THE SOUTHERN PLAINS, WESTERN MAINLAND ALASKA, AND THE ALEUTIANS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE ANTICIPATED FOR THE REMAINDER OF THE FORECAST DOMAIN.
THE TEMPERATURE AND PRECIPITATION ANOMALY PATTERNS FOR WEEK-2 ARE EXPECTED TO BE VERY SIMILAR TO THOSE FORECAST FOR THE 6-10 DAY PERIOD, ALTHOUGH AS THE FORECAST CIRCULATION PATTERN RETROGRADES SLIGHTLY, A SOMEWHAT DRIER REGIME IS ANTICIPATED FOR PARTS OF THE PACIFIC NORTHWEST.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOUT AVERAGE, 3 OUT OF 5, DUE TO FAIR AGREEMENT AMONG THE MODEL SOLUTIONS AND SURFACE TOOLS.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON NOVEMBER 17
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.
Day | ENSO Phase | PDO | AMO | Other Comments |
Oct 28, 1952 | Neutral | – | + | |
Nov 11, 1953 | El Nino | – | + | |
Nov 9, 1954 | La Nina | +(t) | – | |
Nov 11, 1967 | La Nina | – | – | Start of short-lived La Nina |
Nov 12, 1967 | La Nina | – | – | Start of short-lived La Nina |
Nov 11, 1970 | La Nina | – | – | |
Nov 4, 1972 | El Nino | +(t) | – | Strong El Nino |
Nov 5, 1972 | El Nino | +(t) | – | Strong El Nino |
Oct 23, 1973 | La Nina | – | – | Very strong La Nina |
(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 23 to November 12 which is 20 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 2. These analogs are centered on 3 days and 4 days ago (October 27 or 28). So the analogs could be considered somewhat out of sync with the calendar (or almost a week earlier than appropriate for this time of the year) meaning that we will be getting weather that normally would occur a week later into the winter.
There are this time three El Nino Analogs (why are there any?), five La Nina Analogs, and one ENSO Neutral Analog. The phases of the ocean cycles in the analogs point towards McCabe Conditions other than McCabe C. The lack of a clear cut indication of which McCabe condition we are in may explain some aspects of 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 the second half of October, I have now removed the July and August Graphics.
Here is the 30 Days ending October 22, 2016
And the 30 Days ending October 29, 2016
NOAA issued their Seasonal Outlook on October 20 and we reported on that in a special update that you can get to by clicking here. If you opt to go read my Report on NOAA’s Seasonal Outlook Update, please return from there to read the rest of this report which you can do by simply hitting your “backspace” button on your keyboard.
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 October 25, 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.
———————————————— | 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 | May 23, 2016 | |
These Rows Show the Extent of ENSO Neutral Impacts on the Equator | |||||||
0.5C or cooler Anomaly* | 160E | 155E | Land | 155W | 105 | 50 | 50 |
0C or cooler Anomaly | 175E | 155W | LAND | Land | 90 | 50 | 60 |
These Rows Show the Extent of the La Nina Impacts on the Equator | |||||||
-0.5C or cooler | 170W | 145W | LAND | Land | 75 | 50 | 50 |
-1C or cooler Anomaly | 145W | 140W | 110W | 105W | 35 | 25 | 35 |
-1.5C or cooler Anomaly | LAND | 135W | LAND | 120W | 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 October 31, in the afternoon working from the October 30 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 | -0.4 |
B. 160W to 150W | -0.2 | -0.3 |
C. 150W to 140W | -0.3 | -0.6 |
D. 140W to 130W | -0.3 | -0.8 |
E. 130W to 120W | -0.4 | -0.8 |
Total | -1.5 | -2.9 |
Total divided by five subregions i.e. the ONI | (-1.5)5 = -0.3 | (-2.9)/5 = -0.6 |
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 thought it would be useful to show a view which is more focused on the Equator but looks down to 300 meters rather than just being the surface. There was almost no change from last week so I omitted that graphic this week.
Let us further look 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 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 a comparison between Air Pressure at Tahiti and Darwin Australia 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 |
Oct 25 | +4.12 | +2.33 | +6.17 |
Oct 26 | -1.87 | +1.48 | +6.25 |
Oct 27 | -21.02 | +0.21 | +6.05 |
Oct 28 | -35.46 | -1.34 | +5.54 |
Oct 29 | -32.88 | -2.91 | +4.94 |
Oct 30 | -20.24 | -4.50 | +4.58 |
Oct 31 | -4.84 | -5.10 | +4.50 |
The 30-day average, which is the most widely used measure, as of October 31 is reported at -5.10 which is again a tremendous decline from last week and is no longer a La Nina value but actually an El Nino value. The 90-day average at +4.50 is also lower than 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. 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.
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 so far has not been 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 in 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 the Early October CPC/IRI which is more tied to meteorologists reading of tea leaves followed by the later in the month fully Model-Based Forecast issued this week. It is not a big difference (presumably the meteorologists consult their models in addition to reading tea leaves) but it is a difference and a huge one this month. 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).
So first we have the previously released early-month reading of the tea leaves.:
And now the recently updated Model-Based version which indeed is very different than the analysis issued just a week earlier.
We have suggested that it is possible that some of the models and in particular NOAA’s model will be wrong about how fast the Eastern Pacific Warm Pool moves back towards its La Nina location and it may well be that this winter will be more of an ENSO Neutral year with respect to Winter and then Spring or even have some characteristics of an El Nino Modoki (which mostly makes a difference for the East Coast of Asia. It could be less dry than forecast for CONUS as the Warm Pool may still be more in the Central Pacific than shifted all the way west to its strong La Nina position.
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
ENSO outlooks
Outlooks from the eight international climate models surveyed by the Bureau continue to indicate that neutral ENSO conditions are the most likely outcome for the southern hemisphere spring–summer period. However, two models indicate the likelihood of a brief, late-starting La Niña over the summer.
If La Niña does form, models suggest it will be weak, potentially short-lived, and well below the strength of the significant 2010–12 event.
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 continues. Index values remain well below their peak earlier in winter, although have increased in strength over the past fortnight. The weekly index value to 23 October was −0.56 °C.
International climate models indicate the negative IOD will steadily weaken during spring, as is typical of the lifecycle of IOD events. The influence of the IOD on Australian climate is weak during the months December to May as the monsoon trough shifts south over the tropical Indian Ocean.
A negative IOD typically brings above average rainfall to eastern Australia during spring, cooler than normal daytime temperatures to southern Australia, and warmer daytime and night-time temperatures to northern Australia.
Information on the impact of a negative IOD on Australia can be found here.
D. Putting it all Together.
Last winter’s El Nino has officially ended in terms of currently satisfying the criteria. We are now speculating on how the winter of 2016/2017 will evolve. 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.
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
Weather Research in the News
U.S. Operational Numerical Weather Prediction: What’s Wrong and How it Can Be Fixed
Global Warming in the News
Reported two three weeks ago and I am repeating the below because it is very important I have still not had the time to fully digest and analyze this very important report. .
Southwest Mega-drought Risk – Needs to be read carefully. 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.
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 official reading for Jul/Aug/Sept is now reported as -0.5.The JAS reading is the first La Nina Value. So there would now need for there to be four more periods of -0.5 or colder for this to be eligible to be formally recorded as a La Nina. It is possible but it will be close. I doubt that it will happen.
The full history of the ONI readings can be found here. The MEI index readings can be found here.