Written by Sig Silber
Hard to know what the main theme tonight is: Hurricane Paine (which you can track here), first Fall Storm, or the Cool Anomaly shifting west out of the ONI Measurement Area? So I guess we will cover all of that and more.
NOAA updated their Seasonal Outlook on September 15. We reported on that on Sunday Sept 18. You can read that report here. If you opt to go read my Report on NOAA’s Seasonal Outlook Update, please return from there to read this report which you can do by following the instructions at the end of that report or simply hitting your return button.
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, 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 the link provided above.
The explanation for the coding used in these maps, i.e. the full legend, can be found here although it includes some symbols that are no longer shown in the graphic because they are implemented by color coding.
U.S. 3 Day to 7 Day Forecasts
You can enlarge the below daily (days 3 – 7) weather maps by clicking on Three Day or Four Day or Five Day or Six Day or Seven Day
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)
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. I am leaving this explanation in the report but it may not be very significant until next October or so which now is well now!!!.
The graphic below is similar to the above but with more detail which has pros and cons. It highlights the forecasted surface Highs and the Lows re air pressure on Day 6 (the Day 3 forecast is available on Page II of this Report. It you go there, hit your return button to get back to this report). This graphic also auto-updates.
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 weather patterns, except for the Southwest Monsoon, are moving from west to east. It highlights the 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.
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.
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.
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.
Four- Week Outlook
I am going to show the three-month OND Outlook (for reference purposes), the Updated Outlook for the single month of October, the 6 – 10 Day and 8 – 14 Day Maps and the Week 3 – 4 Experimental Outlook.
First – Temperature
Here is the Three-Month OND Temperature Outlook issued on September 15, 2015, 2016:
Here is the Early Temperature Outlook for October which was updated on September 15, 2016
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Looking further out.
Now – Precipitation
Here is the three-month OND Precipitation Outlook issued on September 15, 2016 :
And here is the Early Outlook for October Precipitation Issued on September 15, 2016
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook
.
As I view these maps on September 19 (two of the five update each day and one (the Week 3 – 4 Outlook) updates every Friday), it looks like precipitation leading up to October 14 is tending for the end of September to be dry in the Northwest and wet east of the Rocky Mountains but with a dry East Coast. Going into the first half of October, the pattern will evolve with the wet anomaly contracting and extending from North of Texas northeast all the way to Maine and pushing the dry East Coast anomaly into the Atlantic Ocean.
Here is the NOAA discussion released today September 19, 2016.
6-10 DAY OUTLOOK FOR SEP 25 – 29 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 A TROUGH OVER THE NORTH PACIFIC. DOWNSTREAM, A RIDGE IS FORECAST NEAR CALIFORNIA WITH A TROUGH PREDICTED NEAR THE NORTHERN PLAINS. TODAY’S 500-HPA BLEND CHART DEPICTS BELOW NORMAL HEIGHTS FOR NEW ENGLAND AND PARTS OF THE SOUTHWESTERN CONUS, WHILE NEAR TO ABOVE NORMAL HEIGHTS ARE FORECAST FOR THE REMAINDER OF THE CONUS AND ALASKA. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE LARGE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. TODAY’S MANUAL 500-HPA HEIGHT BLEND IS COMPOSED PRIMARILY OF THE ENSEMBLE MEAN SOLUTIONS. THE GREATEST WEIGHTS WERE GIVEN TO TODAY’S 0Z CANADIAN ENSEMBLE MEAN DUE TO RELATIVELY HIGH ANALOG CORRELATIONS COMPARED TO THE GFS AND ECMWF-BASED SOLUTIONS.
ABOVE NORMAL TEMPERATURES ARE FAVORED OVER MUCH OF THE EAST-CENTRAL CONUS, AND WEST COAST UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS. NEAR TO BELOW NORMAL TEMPERATURES ARE FAVORED FOR THE WEST-CENTRAL CONUS AND NEW ENGLAND IN ASSOCIATION WITH A PREDICTED MEAN TROUGH AND BELOW NORMAL HEIGHTS. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR MUCH OF ALASKA IN ASSOCIATION WITH ABOVE NORMAL HEIGHTS AND ABOVE NORMAL SEA SURFACE TEMPERATURES IN ADJACENT WATERS.
ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE CENTRAL CONUS NEAR THE TROUGH PREDICTED OVER THE NORTHERN PLAINS. POTENTIAL INFLUXES OF TROPICAL MOISTURE MAY AID IN ENHANCING PRECIPITATION AMOUNTS. THERE ARE INCREASED ODDS FOR NEAR TO BELOW MEDIAN PRECIPITATION ACROSS PARTS OF THE PACIFIC NORTHWEST, NORTHERN CALIFORNIA, AND NEVADA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS. BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE MIDDLE ATLANTIC IN ASSOCIATION WITH FORECAST SURFACE HIGH PRESSURE. ABOVE NORMAL HEIGHTS LEAD TO ENHANCED PROBABILITIES FOR BELOW MEDIAN PRECIPITATION FOR THE SOUTH COAST OF ALASKA. MOST DYNAMICAL MODELS FAVOR ABOVE MEDIAN PRECIPITATION FOR WESTERN AND NORTHERN ALASKA.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: AVERAGE, 3 OUT OF 5, DUE TO FAIR MODEL AGREEMENT.
8-14 DAY OUTLOOK FOR SEP 27 – OCT 03, 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 THE OFFICIAL BLENDED HEIGHT PATTERN FEATURES A LOW AMPLITUDE FLOW PATTERN OVER THE CONUS WITH BELOW NORMAL HEIGHTS OVER A SMALL PORTION OF THE NORTHWEST, AND NEAR TO ABOVE NORMAL HEIGHTS ARE FORECAST FOR THE REMAINDER OF THE CONUS AND ALASKA. THE ENSEMBLE SPAGHETTI DIAGRAMS INDICATE MODERATE TO LARGE SPREAD ACROSS THE MAJORITY OF THE FORECAST DOMAIN. THE GREATEST WEIGHTS IN TODAY’S WEEK-2 500-HPA MANUAL HEIGHT BLEND WAS GIVEN TO TODAY’S 0Z CANADIAN ENSEMBLE MEAN MEAN DUE IN PART TO RELATIVELY HIGH ANALOG CORRELATIONS, WHICH MEASURE HOW CLOSELY THE FORECAST PATTERN MATCHES CASES THAT HAVE OCCURRED IN THE PAST.
THERE ARE ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES FOR SOUTHERN CALIFORNIA AND THE EAST-CENTRAL CONUS AS WELL AS ALASKA UNDERNEATH PREDICTED ABOVE NORMAL HEIGHTS. BELOW NORMAL TEMPERATURES ARE FAVORED FOR PARTS OF THE PACIFIC NORTHWEST, THE NORTHERN GREAT BASIN, THE NORTHERN ROCKIES AND NORTHERN PLAINS IN ASSOCIATION WITH NEAR TO BELOW NORMAL HEIGHTS.
THE FORECAST PRECIPITATION PROBABILITIES FOR THE WEEK-2 PERIOD ARE VERY SIMILAR TO THOSE IN THE 6-10 DAY PERIOD. ABOVE MEDIAN PRECIPITATION IS FAVORED FOR THE CENTRAL CONUS, AND WESTERN AND NORTHERN ALASKA. THERE ARE INCREASED ODDS FOR NEAR TO BELOW MEDIAN PRECIPITATION ACROSS THE PACIFIC NORTHWEST, NORTHERN CALIFORNIA, NEVADA, THE MIDDLE ATLANTIC, AND THE ALASKA PANHANDLE.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: AVERAGE, 3 OUT OF 5, DUE TO FAIR MODEL AGREEMENT.
THE NEXT SET OF LONG-LEAD MONTHLY AND SEASONAL OUTLOOKS WILL BE RELEASED ON OCTOBER 20
Some might find this analysis interesting as the organization which prepares it looks at things from a very detailed perspective and their analysis provides a lot of information on the history and evolution of 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 |
Sept 18, 1958 | El Nino | + | + | |
Sept 6, 1959 | Neutral | – (t) | + | |
Sept 19, 1960 | Neutral | – (t) | + | |
Sept 21, 1960 | Neutral | – (t) | + | |
Sept 9, 1982 | El Nino | + | – | Strong El Nino |
Sept 23, 1992 | Neutral | – | – | After an El Nino |
Sept 24, 1992 | Neutral | – | – | After an El Nino |
Sept 12,2004 | El Nino | + (t) | + | 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 September 6 to September 24 which is just four days over two weeks which is a very small 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 September 15. These analogs are centered on 3 days and 4 days ago (September 15 or 16). So the analogs could be considered exactly in sync with the calendar meaning that we will be getting weather that normally would occur this time of the year including that forecast trough which is typical this time of the year.
There are this time three El Nino Analogs (why are there any?), zero La Nina Analogs (why are there none?), and three ENSO Neutral Analogs. The phases of the ocean cycles in the analogs are inconclusive with only McCabe “Condition A” not well represented and it is the most wet McCabe Condition and fits best with the NOAA 6 – 14 Day Outlook. It is confusing.
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 September, I have now removed the June and June – April – May – June 90 Day Graphics. They are available in Part II of this Report – If you click to go there and take a look, hit your “Return Key” to return to this article.
Let’s look at the temperature and precipitation anomalies for the 30 days ending July 30, 2016
And now we looking at August. Here are the 30 Days ending September 3.
And the 30 Days ending September 17, 2016
B. Beyond Alaska and CONUS Let’s Look at the World which of Course also includes Alaska and CONUS
Click Here for a World Weather Forecast produced by the Australian Bureau of Meteorology. Unfortunately I do not know how to extract the map only so to see it you have to click where I said “click here”. You can adjust the settings to show Temperature or many other things for THE WORLD. It can forecast out for a week. Pretty cool.
But I know how to display the precipitation only forecast from Queensland Australia and here it is.
And lo and behold JAMSTEC has issued their Precipitation Forecast
Just to be complete I will show their temperature forecast
Cure for Global Warming? Or an illustration of how trends are difficult to deal with by adjusting the norm?
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 September 13. 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* | 165E | 155E | Land | 155W | 100 | 50 | 50 |
0C or cooler Anomaly | 175E | 155W | 120W | Land | 55 | 50 | 60 |
These Rows Show the Extent of the La Nina Impacts on the Equator | |||||||
-0.5C or cooler Anomaly | 175W | 145W | 125W | Land | 50 | 45 | 55 |
-1C or cooler Anomaly | 145W | 140W | 135W | 105W | 15 | 15 | 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 September 19, in the afternoon working from the September 18 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | -0.2 | -0.3 |
B. 160W to 150W | -0.6 | -0.5 |
C. 150W to 140W | -1.0 | -0.6 |
D. 140W to 130W | -0.8 | -0.5 |
E. 130W to 120W | -0.5 | -0.0 |
Total | -3.1 | -1.9 |
Total divided by five subregions i.e. the ONI | (-3.1)/5 = -06 | (-1.9)/5 = -0.4 |
My estimate of the daily Nino 3.4 SST anomaly has risen to -0.4 which is no longer a La Nina value. NOAA has reported the weekly ONI to be a bit warmer at -0.6 which still is a La Nina value.But I question the accuracy of their calculation. It is entirely possible that the TAO/TRITON system is not reporting accurately (and I may thus be underestimating the SST anomalies in the Eastern end of the Nino 3.4 Measurement Area) or I may simply have made an error in my estimation of the value for Nino 3.4 from the TAO/TRITON graphic. The difference between -0.4 and -0.6 is not enormous but it is substantial. There are some differences among what I see in the different graphics which are available so it is hard to say what the correct estimate is. Also there appears to be a short-term cyclical component to the SST anomaly pattern. I have estimated a daily value for Nino 3.4 and NOAA has reported a weekly value so that cyclical aspect can cause a difference on its own.Nino 4.0 is reported as being a bit cooler at -0.2. Nino 3 is being reported a bit warmer at -0.2 Nino 1 + 2 which extends from the Equator south rather than being centered on the Equator is being reported cooler at +0.2. According to NOAA we remain in ENSO Neutral but we have had our tenth straight LA NINA value of Nino 3.4 reported in the NOAA Weekly Report. The Australian Bureau of Meteorology recently reported that their estimate of the value for NINO 3.4 for August was -0.4. IT IS THE SAME OCEAN. They are forecasting that the value for NINO 3.4 will decline to about-0.6 for September. So it looks like people are getting on the same page but the NOAA estimates appear to be a tad lower i.e. more La Nina-ish than the others.Ten weeks are not definitive (the NOAA criteria for declaring an El Nino or La Nina includes five overlapping three-month periods with the appropriate conditions) especially without confirmation from the SOI which we may have now finally. These index measurements are not definitive but they suggest the direction things are headed but other information strongly suggests the ONI readings will soon (NOAA) or after September (Australia BOM) be less negative than they are this week. I am only showing the currently issued version of the NINO SST Index Table as the prior values are shown in the small graphics on the right with this graphic. The same data in table form but going back a couple of more years can be found here. NINO 1+ 2 stubbornly remains positive and determines the weather of Ecuador and Peru.
Sea Surface Temperature and Anomalies
It is the ocean surface that interacts with the atmosphere and causes convection and also the warming and cooling of the atmosphere. So we are interested in the actual ocean surface temperatures and the departure from seasonal normal temperatures which is called “departures” or “anomalies”. Since warm water facilitates evaporation which results in cloud convection, the pattern of SST anomalies suggests how the weather pattern east of the anomalies will be different than normal.
A major advantage of the Hovmoeller method of displaying information is that it shows the history so I do not need to show a sequence of snap shots of the conditions at different points in time. This Hovmoeller provides a good way to visually see the evolution of this ENSO event. I have decided to use the prettied-up version that comes out on Mondays rather that the version that autoupdates daily because the SST Departures on the Equator do not change rapidly and the prettied-up version is so much easier to read.
And here is another but related view of the data that is focused right on the Equator but considers the water down to 300 meters. This graphic provides a lot of useful information but I usually present it to show the evolution of Kelvin Waves which we have not seen since last year. Usually we pay the most attention to the downwelling phase of the Kelvin Wave where warm water moves East as part of the generation of an El Nino. But when one is looking at a cool event, the subsequent upwelling phase of Kelvin Waves is of interest and this graphic shows that phase well.
Let us 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.
It shows the thermocline between warm and cool water. The 28C Isotherm is now located at 175W which is about the same as last week.This graphic does not show a 27.5C anomaly which might more precisely indicate where convection is likely to occur. The 27C isotherm is now at 170W so we do not have ideal conditions for significant convection along the Equator east of the Dateline. The 25C isotherm is again at about 140W. The 20C Isotherm has moved close to the surface but is not reaching the surface. But the amount of warm water just west of the Dateline is also not real impressive either but growing but staying fairly far east. It is clearly a transition state and all of this is important not just for tracking this cool event but thinking about when the next El Nino might be triggered. This graphic helps understand the logic behind some of the forecasts of the ONI. For the past two+ months, we pretty much have had weak La Nina conditions both in terms of water temperatures and the SOI but it appears to be transitory in the sense of the SST’s moving more towards La Nina this week with the SOI also flashing La Nina. So it is still a battle going on with La Nina nudging ahead but not looking like it can sustain itself. .
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 |
Sept 13 | +30.78 | +9.31 | +5.74 |
Sept 14 | +27.46 | +10.37 | +6.08 |
Sept 15 | +20.68 | +11.16 | +6.14 |
Sept 16 | +15.51 | +11.77 | +6.06 |
Sept 17 | +18.25 | +12.49 | +6.10 |
Sept 18 | +14.14 | +12.75 | +6.14 |
Sept 19 | +12.54 | +13.05 | +6.29 |
The 30-day average, which is the most widely used measure, as of September 19 is reported at +13.05 which is up markedly from last week and is definitely a La Nina level. The 90-day average at +6.29 is up from last week and is now at a La Nina level. These may be the high water marks for the SOI re this cycle but I said that 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. Different agencies use a different range to classify the SOI as being El Nino or La Nina. The tightest range (I have referred to that as “strictest” but that may not be a clear way of putting it) is -5 for El Nino and +5 for La Nina. Some meteorological agencies sometimes use -8 or +8. So the range +5 to -5 is clearly neutral and above +8 is clearly La Nina and below -8 is clearly El Nino and between -8 and -5 and +5 to + 8 is somewhat marginal but suggestive of El Nino if negative and La Nina if positive. For many purposes the trend is more important than the absolute level. So clearly the Upper Atmosphere has a trend right now towards 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. September so far has not been particularly favorable for La Nina development and neither will be October in terms of the MJO. 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. Right now the impact is fairly muted. It 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.
Forecasting the Evolution of ENSO
The below is first the CPC/IRI (Early Month) forecast issued on September 8, 2016 followed by the (Late Month) forecast issued on September 15, 2016. It is important to remember that the first report in each month is based on a survey of meteorologists and the second report later in the month is based on the analysis of the forecast models. It is a minor difference but a difference.
First the Early September “Probabilistic Forecast which includes a large component of input from meteorologists as compared to the second forecast in the month which is more tied to model results without interpretation. It is not a big difference but it is a difference. 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).
And now we have the newly released mid-month model based report
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 next winter will be more of a Neutral year or even have some characteristics of an El Nino Modoki and thus be wetter than a typical year as the Warm Pool may still be more in the Central Pacific than shifted all the way west to its La Nina position.
The full list of weekly values can be found here.
Forecasts from Other Meteorological Agencies.
Here is the report issued September 11 from the Australian BOM
We now have the new JAMSTEC September 1 ENSO forecast.
Aug. 17, 2016 Prediction from 1st Aug., 2016
ENSO forecast:
The SINTEX-F model initialized with the SST condition observed on July 31st predicts a weak La Niña/La Niña Modoki state in coming months. [Editor’s Note: This article is already running too long so we will not discuss La Nina Modoki tonight but here is a good article to read for those with an interest in the topic]. Although the NCEP GODAS shows an anomalously cold subsurface condition almost all the way from central Pacific to eastern Pacific along the equator in July, the prediction has not picked the strong La Niña/La Niña Modoki signal yet. This might be a model bias due to the simple SST data assimilation scheme used in the initialization. However, we have noted similar prediction results in several other climate models.
Indian Ocean forecast:
As predicted earlier, the negative Indian Ocean Dipole (IOD) has actually emerged in the June-July SST anomalies of the NCEP GODAS data. The model continues predicting the negative IOD for the boreal fall; this will bring a wetter-than-normal (drier-than-normal) condition over the eastern (western) side of the Indian Ocean. There is high possibility of floods in the region near Sumatra and Java, and drought in East Africa. The negative IOD seems to have brought temporary relief to a hot summer over East Japan normally expected in an evolving La Niña year.
Regional forecast:
In boreal fall, as a seasonally averaged view, most part of the globe will experience a warmer-than-normal condition, while northern Brazil will experience a colder-than-normal condition.
According to the seasonally averaged rainfall prediction, U.S., Korea, eastern China, Indo-China and East Africa will experience a drier condition during boreal fall, while most parts of Indonesia and northwestern South America (including Colombia, Ecuador, and western Brazil) will experience a wetter-than-normal condition; this may be mostly due to the negative IOD and the evolving weak La Niña. Also, because of those climate conditions in Indian and Pacific Oceans, Australia is expected to receive above normal rainfall during austral spring and summer. The active South Pacific Convergence Zone (SPCZ) may play a role in this, too However, we expect a weak dry condition in the southwestern coastal region of Western Australia because of the evolution of weak Ningaloo Niña. [ Editor’s Note: Click for Explanation and even more detail on the Ningaloo Niña]
Most part of Japan will experience above normal temperature from summer through winter. We expect above normal precipitation in most part of Japan in September-October. However, it may be noted that the forecast skills in those mid- and high-latitudes on regional scales are still limited.
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 the winter of 2016/2017 which now according to some of the models seems likely to be a La Nina or Neutral with a La Nina bias. 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. 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
We have discussed Hurricane Paine within the report.
Weather Research in the News
“What caused the extreme rainfall in Louisiana” I think this is more of a risk analysis than an attribution analysis but either way it indicates that “Houston we have a Problem?”
California Megadroughts. If you are not able to access the Washington Post Article you can read the full paper here.
Global Warming in the News
The articles in the Weather Research category would fit here as well.
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 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 Jun/Jul/Aug is now reported as -0.3. As you can see this recent El Nino peaked in NDJ and has now ended and depending on what system you use it is either the 2nd or 3rd strongest El Nino since modern records were kept which is considered to be 1950. You could argue for it being #1 based on a week of readings but few are buying that argument. Still #2 or #3 means it is one of the strongest ever based on the way these events are measured. I will be writing more about that soon in a separate article. I believe the measurement system is inadequate re being useful in forecasting Worldwide weather impacts. The JJA is not a La Nina Value. So there would need for there to be five periods of -0.5 or colder starting with JAS. It is not even clear that JAS will record as -0.5 or less. So the chances of this event being an official La Nina are very low.
The full history of the ONI readings can be found here. The MEI index readings can be found here.