Written by Sig Silber
The NOAA theory of a Monsoon in March looks like it is not working out. Perhaps they should have paid attention to the southeastward migration of the Aleutian Low which would on the one hand make such a bizarre pattern more unlikely but at the same time make an actual El Nino Pattern more likely. Our theory is that as the El Nino has weakened, it has begun to fit into the domain of prior El Nino events and statistical methods for predicting the impacts are now more sound statistically. Read more and you will see what NOAA has to say about all of this.
This is the Regular Edition of my weekly Weather and Climate Update Report. Additional information can be found here on Page II of the Global Economic Intersection Weather and Climate Report.
NOAA has updated their Early Outlook for March.
Prior Temperature Outlook.
Here is the previously issued “Early Outlook” for March Temperature.
Newly Updated Temperature Outlook
Here is the previously issued “Early Outlook” for March Precipitation.
Newly Updated Precipitation Outlook
Excerpts from the NOAA Discussion released today February 29
30-DAY OUTLOOK DISCUSSION FOR MARCH 2016
THE MONTHLY TEMPERATURE AND PRECIPITATION OUTLOOK IS UPDATED AT THE END OF THE MONTH USING THE LATEST DYNAMICAL MODEL GUIDANCE FROM THE NCEP CLIMATE FORECAST SYSTEM FOR MARCH, AS WELL AS REFORECAST-CALIBRATED GUIDANCE FOR THE SECOND WEEK OF THE MONTH FROM THE NCEP GLOBAL ENSEMBLE FORECAST SYSTEM (GEFS) AND ECMWF ENSEMBLE PREDICTION SYSTEM, BIAS-CORRECTED MODEL FORECASTS FROM THE CFS AND ECMWF ENSEMBLE MODELS FOR THE THIRD AND FOURTH WEEK, AND PRECIPITATION AND TEMPERATURE ANOMALY FORECASTS FOR THE BEGINNING OF THE MONTH FROM THE WEATHER PREDICTION CENTER (WPC).
THE UPDATED TEMPERATURE OUTLOOK EXPANDS THE AREA OF INCREASED PROBABILITIES FOR ABOVE-NORMAL TEMPERATURES ACROSS THE CENTRAL MISSISSIPPI AND OHIO VALLEYS TO THE MID-ATLANTIC COASTAL STATES, AND NORTHERN REGIONS OF THE SOUTHEAST. THE INCREASED PROBABILITY FOR ABOVE-NORMAL TEMPERATURES IS SUPPORTED BY THE CFS MARCH FORECAST, AS WELL AS GUIDANCE FOR WEEK 2 FROM THE GEFS AND ECMWF ENSEMBLES AND WEEKS 3 AND 4 FROM THE ECMWF AND CFS ENSEMBLES. A TRANSITION, FROM BELOW-NORMAL TEMPERATURES EARLY IN THE MONTH TO ABOVE-NORMAL TEMPERATURES THEREAFTER, IS PREDICTED. IN OTHER REGIONS, THE FORECAST OF ENHANCED CHANCES OF ABOVE-NORMAL TEMPERATURES CONTINUES IN MUCH OF THE WEST. THE AREA OF ENHANCED PROBABILITIES OF BELOW-NORMAL TEMPERATURES IN THE SOUTHWEST IS REDUCED AND MOVED WESTWARD FROM THE HALF-MONTH LEAD OUTLOOK, AS INDICATED BY THE LATEST MODEL GUIDANCE FOR WEEKS 2 TO 4.
THE UPDATED PRECIPITATION OUTLOOK FOR MARCH IS SIMILAR TO THE HALF-MONTH LEAD, INDICATING ENHANCED PROBABILITIES FOR ABOVE-MEDIAN PRECIPITATION ACROSS MUCH OF THE SOUTHWEST, THE CENTRAL AND SOUTHERN PLAINS STATES, AND THE GULF AND SOUTH ATLANTIC COASTS. FORECASTS FOR PRECIPITATION EARLY IN THE MONTH RESULT IN INCREASED CHANCES OF ABOVE-MEDIAN PRECIPITATION FOR THE PACIFIC COAST OF WASHINGTON, AS WELL AS WESTERN OREGON AND NORTHERN CALIFORNIA. DECREASED CHANCES OF ABOVE MEDIAN PRECIPITATION FOR THE NEW ENGLAND COAST, FROM THE PREVIOUS OUTLOOK, ARE INDICATED BY FORECASTS FOR THE BEGINNING OF THE MONTH FOR BELOW OR NEAR-MEDIAN PRECIPITATION. THE AREA OF ENHANCED CHANCES OF BELOW MEDIAN PRECIPITATION FOR THE PACIFIC NORTHWEST, IN THE HALF-MONTH LEAD OUTLOOK, HAS BEEN MOVED SLIGHTLY EASTWARD FOLLOWING RECENT MODEL GUIDANCE, AND IN CONSIDERATION OF PRECIPITATION FORECASTS FOR THE FIRST HALF OF THE MONTH. THE AREA OF ENHANCED PROBABILITIES FOR BELOW-MEDIAN PRECIPITATION IN THE OHIO VALLEY AND CENTRAL GREAT LAKES REGION IN THE HALF-MONTH LEAD OUTLOOK IS REMOVED IN THE MONTHLY UPDATE, WITH SIGNIFICANT PRECIPITATION PREDICTED FOR THIS REGION IN THE FIRST HALF OF THE MONTH.
Sometimes it is useful to compare the present month outlook to the three-month outlook
March plus March – April – May Outlook
One can mentally subtract the March Outlook from the three-month Outlook and create the Outlook for the last two months in the three-month period namely April and May 2016. When I do that, I deduce that April and May will be:
One has to keep in mind that we are now subtracting a March Map issued on February 29 from a February 18 Three-month map so it is less reliable than the exercise we went through last week. We are assuming that the three-month outlook issued on February 18 would not change if it was released today. The results in the box above might be an indication of how April and May will differ from the three-month outlook or it might alternatively indicate how the three-month outlook might be modified if issued today. Also early March is being impacted by the Active Phase of the MJO and that was definitely not considered during the preparation of the three-month outlook on February 18, 2016 since the exact timing of the phases of the MJO would not have been able to have been forecast at that time. Thus the changes in March are to a large extent related to the Active Phase of the MJO and probably would not change what NOAA would predict for April and May even if they reissued their maps on February 29.
Let’s Now Focus on the Current (Right Now to 5 Days Out) Weather Situation.
A more complete version of this report with daily forecasts is available in Part II. This is a summary of that more extensive report. This link Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks will take you directly to that set of information but it may take a few seconds for your browser to go through the two-step process of getting to Page II and then moving to the Section within Page II that is specified by this link.
First, here is a national animation of weather front 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.
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.
The MJO has been shifting back to its active phase this week and will peak perhaps next week. The MJO is thought to be relatively unimportant during the winter but perhaps a strong El Nino increases the relevance of the MJO: another research question for NOAA.
Notice the Northern Pacific is like a giant anticyclone with clockwise motion so that which gets sent west due to El Nino is to some extent returned to North America but at higher latitudes.
As I am looking at the below graphic Monday evening February 29, I still see a northern displaced weather pattern. This graphic updates automatically so it most likely will look different by the time you look at it as the weather patterns are moving from west to east although there is some talk of some parts of the pattern being retrograde and moving to the west.
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 Feb 23, 2016 Version and looking at Week 2 of that forecast.
Below is a graphic which 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). This graphic also auto-updates.
Looking at the current activity of the Jet Stream
And here 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.
Here is 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.
And when we look at Sea Surface anomalies below,
We see a lot of them not just along the Equator related to El Nino.
Below I show the changes over the last month in the Sea Surface Temperature (SST) anomalies.
6 – 10 Day Outlook
Now let us focus on the 6 – 14 Day Forecast for which I generally only show the 8 – 14 Day Maps. The 6 – 10 Day maps are always available in Part II of this report but in the winter I often show both maps as the forecasted weather patterns change during that nine day period.
To put the forecasts which NOAA tends to call Outlooks into perspective, I am going to show the three-month MAM Outlook and the newly updated Outlook for the single month of March and then discuss the 8 – 14 day Maps and the 6 – 14 Day NOAA Discussion within that framework.
First – Temperature
Here is the Three-Month Temperature Outlook issued on February 18, 2016:
Here is the newly updated Outlook for March Temperature.
Below is the current 6 – 10 Day and 8 – 14 Day Temperature Outlook Maps which will auto-update and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that all winter as the patterns are moving from west to east fairly rapidly.
6 – 10 Day Temperature Outlook
8 – 14 Day Temperature Outlook
Now – Precipitation
Here is the three-month Precipitation Outlook issued on February 18, 2016:
Here is the recently updated Outlook for March Precipitation.
Below are the current 6 – 10 Day and 8 – 14 Day Precipitation Outlook Maps which will auto-update and thus be current when you view them. It covers the nine days following the tail end of the current week. I have included both today and probably will continue to do that all winter as the patterns are moving from west to east fairly rapidly.
6 – 10 Day Precipitation Outlook
8 – 14 Day Precipitation Outlook
Here are excerpts from the NOAA discussion released today February 29, 2016. It covers the full nine-day period and this week I have shown both the 6 -10 Day and the 8 – 14 Day Maps.
6-10 DAY OUTLOOK FOR MAR 06 – 10 2016
TODAY’S MODEL SOLUTIONS ARE IN VERY GOOD AGREEMENT ON THE 6-10 DAY, 500-HPA HEIGHT PATTERN. MODEL FORECASTS INDICATE TROUGHING OVER THE GULF OF ALASKA, SPLIT FLOW OVER THE WESTERN CONUS WITH SOUTHERN STREAM TROUGHING, AND RIDING FROM THE SOUTHEAST TO THE GREAT LAKES. IN THE 500-HPA HEIGHT MANUAL BLEND, HEIGHTS ARE FORECAST TO BE BELOW AVERAGE FOR ALASKA AND FROM THE WEST COAST TO THE GREAT PLAINS, WITH ABOVE AVERAGE HEIGHTS FROM THE GREAT PLAINS TO THE EAST COAST. THAT BLEND CONSISTS OF MOSTLY ENSEMBLE MEANS, AS THE DETERMINISTIC MODELS DIFFER VERY LITTLE FROM THEIR RESPECTIVE ENSEMBLE MEANS. THE BLEND FAVORS SOLUTIONS FROM THE EUROPEAN CENTER AND ENVIRONMENT CANADA, WHICH BOTH HAVE SOLUTIONS SLIGHTLY SLOWER THAN THE GFS FOR THIS CASE, AND HAVE SLIGHTLY HIGHER ANALOG CORRELATION SCORES.
THE RESULTING SURFACE OUTLOOK FOR TEMPERATURES FAVORS ABOVE NORMAL TEMPERATURES FOR THE CONUS, EXCEPT FOR OREGON, CALIFORNIA, NEVADA, AND ARIZONA, WHERE UPPER-LEVEL TROUGHING IS FORECAST TO RESULT IN AN ACTIVE WEATHER PATTERN. MEAN SOUTHERLY FLOW IS ALSO CONTRIBUTING TO ELEVATED ODDS FOR ABOVE NORMAL TEMPERATURES FROM THE GULF COAST TO THE GREAT LAKES. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR EASTERN AND NORTHERN ALASKA, AS THOSE AREAS ARE FORECAST TO BE EAST OF THE MEAN TROUGH, WHILE BELOW NORMAL TEMPERATURES ARE FORECAST FOR WESTERN ALASKA AS THAT AREA IS LIKELY TO BE INFLUENCED BY AIR FROM SIBERIA.
THE RESULTING TROUGHING THAT IS FORECAST TO EXTEND FROM THE GULF OF ALASKA TO THE SOUTHWEST FAVORS INCREASED ODDS FOR ABOVE MEDIAN PRECIPITATION FOR THE ENTIRE WESTERN CONUS. AS SHORTWAVE TROUGHS PROGRESS EASTWARD OUT OF THE MEAN TROUGH IMPACTING THE WEST, LEE CYCLOGENESIS AND SOUTHERLY MEAN FLOW FAVOR ABOVE MEDIAN PRECIPITATION ACROSS THE GREAT PLAINS. LOW-LEVEL AND UPPER-LEVEL RIDGING FAVOR A WEAKENING OF THE ACTIVITY NEAR THE EAST COAST, SO BELOW MEDIAN PRECIPITATION IS FAVORED FOR THE EAST COAST STATES. BELOW MEDIAN PRECIPITATION IS FAVORED FOR INTERIOR AND WESTERN ALASKA, AS LOW-LEVEL MEAN FLOW IS FORECAST TO BE FROM THE EAST, WHICH IS NOT A MOIST FLOW PATTERN.
FORECAST CONFIDENCE FOR THE 6-10 DAY PERIOD: MUCH ABOVE AVERAGE, 5 OUT OF 5, DUE TO GOOD MODEL AND TOOL AGREEMENT.
8-14 DAY OUTLOOK FOR MAR 08 – 14 2016
MODEL AGREEMENT ON THE 500-HPA HEIGHT PATTERN DURING DAYS 8-14 IS VERY GOOD. ALL OF THE AVAILABLE MODELS DEPICT TROUGHING OVER THE GULF OF ALASKA, WEAKLY SPLIT FLOW OVER THE CENTRAL CONUS, AND RIDGING OVER THE EASTERN CONUS. THE DETERMINISTIC GFS SOLUTIONS DEPICT A STRONGER AND MORE PROGRESSIVE PATTERN OVER THE SOUTHERN CONUS, WHILE THE ENVIRONMENT CANADA MODELS ARE SLOWEST WITH FEATURES IN THE SOUTHERN STREAM. ACROSS THE NORTHERN CONUS, MODEL SOLUTIONS ARE NEARLY IDENTICAL.
THE FORECAST FOR SURFACE TEMPERATURE FAVORS ABOVE NORMAL TEMPERATURES FOR THE CONUS, EAST OF THE ROCKIES, WITH THE HIGHEST PROBABILITIES NEAR THE GREAT LAKES. BELOW NORMAL TEMPERATURES ARE FAVORED OVER THE GREAT BASIN AND PORTIONS OF THE SOUTHWEST, WHERE AN ACTIVE STORM TRACK INTO THE WEST IS LIKELY DURING THE 8-14 DAY PERIOD. ABOVE NORMAL TEMPERATURES ARE FAVORED FOR EASTERN AND NORTHERN ALASKA, AS THOSE AREAS ARE FORECAST TO BE EAST OF THE MEAN TROUGH, WHILE BELOW NORMAL TEMPERATURES ARE FORECAST FOR WESTERN ALASKA AS THAT AREA IS LIKELY TO BE INFLUENCED BY AIR FROM SIBERIA.
ABOVE MEDIAN PRECIPITATION IS FAVORED ACROSS MOST OF THE CONUS, EXCEPT FOR NEAR THE NORTHERN ROCKIES, WHERE NEAR NORMAL PRECIPITATION IS FAVORED. TROUGHING OVER THE GULF OF ALASKA FAVORS ABOVE MEDIAN PRECIPITATION FOR MUCH OF THE WESTERN CONUS, WHILE DOWNSTREAM CYCLOGENESIS OVER THE GREAT PLAINS, WHEN COMBINED WITH MEAN SOUTHERLY FLOW, FAVORS ENHANCED ODDS FOR ABOVE MEDIAN PRECIPITATION FROM THE GULF COAST TO THE UPPER GREAT LAKES . MEAN EASTERLY FLOW FAVORS BELOW MEDIAN PRECIPITATION FOR MUCH OF ALASKA.
FORECAST CONFIDENCE FOR THE 8-14 DAY PERIOD IS: ABOVE AVERAGE, 4 OUT OF 5, DUE TO GOOD OVERALL AGREEMENT AMONG THE ENSEMBLE MEAN SOLUTIONS, BUT OFFSET BY UNCERTAINTIES BETWEEN VARIOUS SURFACE TEMPERATURE AND PRECIPITATION TOOLS.
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 this El Nino.
Analogs to Current Conditions
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 analyzing this second set of information. This first set applies to the 5 and 7 day observed pattern prior to today. The second set which I am not using relates to the forecast outlook 6 – 10 days out to similar patterns that have occurred in the past during the dates covered by the 6 – 10 Day Outlook. That may also be useful information but they put this set of analogs in the discussion with the other set available by a link so I am assuming that this set of analogs is the most meaningful.
Analog Centered Day | ENSO Phase | PDO | AMO | Other Comments |
Feb 13, 1970 | El Nino | + | – | |
Feb 17, 1970 | El Nino | + | – | |
Feb 18, 1970 | El Nino | + | – | |
Feb 20, 1970 | El Nino | + | – | |
Feb 24, 1980 | El Nino | + | – | Modoki Type II |
Mar 13, 2000 | La Nina | – | N | Strong and Long La Nina |
Feb 16, 2004 | Neutral | + | + |
One thing that jumped out at me right away was tight spread among six of the seven the analogs from Feb 13 to February 24 which is not even two weeks.
There are this time five El Nino Analogs and one ENSO Neutral Analog and one La Nina Analog suggesting that El Nino is again in full control over our weather for the next 6 – 14 Days. But the El Nino analogs are associated with weak El Ninos. The phases of the ocean cycles in the analogs are clearly indicating McCabe Condition A which suggests that our weather may finally become wet especially for the Southwest (see below). 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.
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.
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 |
Progress of the Warm Event
Let us start with the SOI.
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 |
Feb 23 | -46.1 | -13.17 | -15.67 |
Feb 24 | -34.3 | -14.02 | -16.01 |
Feb 25 | -25.7 | -14.53 | -16.16 |
Feb 26 | -28.6 | -15.00 | -16.23 |
Feb 27 | -30.1 | -15.62 | -16.29 |
Feb 28 | -40.4 | -16.83 | -16.56 |
Feb 29 | -49.1 | -18.55 | -16.85 |
The Inactive Phase of the MJO has switched over to its active phase so we are seeing SOI values which are quite a bit more negative. The 30-day average, which is the most widely used measure, as of February 29 is reported at -18.55 which is definitely a reading that is associated with an El Nino (usually required to be more negative than -8.0 but some consider -6.0 value good enough) and it is very much higher (smaller negative number) than last week. The 90-day average remains in El Nino territory at -16.85 is also a change from last week but amazingly not much of a change. The SOI continues to be indicative of an El Nino Event in progress but it is pretty much passed the time of year where it is very meaningful re El Nino development but it is trying to make a point. It is difficult to know what this means. The February 29 SOI reading is similar to the reading last week which was also the strongest of this El Nino and is related to weather conditions in Tahiti but still WOW! Can you say MJO?
Low-Level Wind Anomalies
Here are the low-level wind anomalies. In October, the area from 180W to 160W was of interest and quite intense. There then was an area of interest at 160W which also was quite intense. Now, calm appears to prevail but there recently was a WWB (Westerly Wind Burst) in January near and east of the Date Line related to Tropical Storm Pali which has long since dissipated. But look at the intensity of the wind anomaly associated with that WWB: 14 That might be “all she wrote” for this El Nino as calm winds prevail. Well that is until last week when we had MJO induced WWB at 180W to 160W. I suspect it is too late to generate Kelvin Wave #6.
In the below graphic, you can see how the convection pattern recently appeared to be shifting ever so slightly a bit to the east but not as far east as we would expect with a strong El Nino. Now that slight movement to the East has reversed. You can also see convection firing up in the Indian Ocean which may or may not be significant.
I do not usually show this graphic.
Let us now take a look at the progress of Kelvin Waves which are the key to the situation. You can see all five of the Kelvin Waves which created this El Nino in this Hovmoeller graphic. From the earliest to the most recent they can be named #1 through #5.
Kelvin Wave # 5 did slow the retreat to the west of the Eastern Pacific Subsurface Warm Pool. That is why I believe the transition to ENSO Neutral will proceed more slowly than some have predicted.
Here is a fancier version of the graphic above…issued today by NOAA as part of their weekly ENSO report. I do not usually use it because it does not auto-update i.e. it is frozen in time. But it is graphically easier to read and contains useful commentary from NOAA. Last week they had essentially called the Coup de Grace El Nino ending upwelling phase of Kelvin Wave #5 but had not drawn it in probably because it was not exactly clear how to draw it yet. That has now happened. Notice all that blue area. It already extends into the Nino 3.4 Measurement Area i.e. it is all the way to 150. You can also see the less warm area in the Eastern Tropical Pacific. There is no indication that this Kelvin Wave will extend further to the east.
We are now going to change the way we look at a three dimensional view of the Equator and move from the surface view to the view from the surface down. This El Nino appears to be fading slowly from west to east. The real decline will be from east to west.
Current Sub-Surface Conditions
Top Graphic (Anomalies)
The above graphic 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.
The top graphic is still the most useful of the two and shows
Bottom Graphic (Absolute Values which highlights the Thermocline)
The bottom half of the graphic may soon become more useful in terms of tracking the progress of this Warm Event as it converts to ENSO Neutral and then La Nina.
It shows the thermocline between warm and cool water which pretty much looks like this as shown here during a Warm Event. You can see that the cooler water is not yet fully making it to the surface to the east along the coast of Ecuador. In fact, the 25C Isotherm now reaches the surface. We now will pay more attention to the 28C Isotherm as west of that temperature is where convection is more easy to occur. The 28C Isotherm has pretty much remained in the same place for months now.
Here are the above graphics as a time sequence animation. You may have to click on them to get the animation going.
TAO/TRITON GRAPHIC
Let us compare the situation as reported on October 4 to the most recent graphic. Remember each graphic has two parts the top part is the average values, the bottom part is those values expressed as an anomaly compared to the expected values for that date. Generally I am mainly discussing the bottom of the pairs of graphics namely the anomalies
First the October 4 version which I am providing for purposes of comparison. I “flash froze” the daily value that day so that it would not auto-update.
And then the December 14 version which I also “flash froze” to stop it from updating.
And then the current version of the TAO/TRITON Graphic.
———————————————— | A | B | C | D | E | —————– |
And an earlier but recent reference point close to the peak of this El Nino re the bottom half of the TAO/TRITON Graphic. You can certainly see the difference that six weeks makes.
The below table tracks the changes. It only addresses the situation right on the Equator so visually the TAO/TRITON graphic contains more information. But the below table turns visual information into quantitative information so it may be useful. The degrees of coverage shown in the rightmost two columns shows that the extent of the warm water directly on the Equator has been reduced in the past few weeks. The way I constructed the table, the 1.0C anomaly as an example includes all water warmer than 1.0C so the 1.5C anomaly is included within it as well as the 2.0C anomaly which you can tell by the way I recorded the westward and eastward coordinates. I could have constructed this table in a different way. Note the 3C anomaly no longer exists. The 2.5C anomaly also no longer exists as of mid-week. As this El Nino decays I am including the less warm anomalies in the table below.
Subareas of the Warm Anomaly | Westward Extension | Eastward Extension | Degrees of Coverage | |||
Today | January 19, 2016 | Today | January 19, 2026 | Today | January 19, 2016 | |
3C Anomaly | Gone | 158W | Gone | 134W | 0 | 24 |
2.5C Anomaly | Gone | 165W | Gone | 110W | 0 | 55 |
2.0C Anomaly | 175W | 170W | 110W | 100W | 65 | 70 |
1.5C Anomaly | 175E | 175W | Land | Land | 90 | 80 |
1.0C Anomaly | 170E | 175E | Land | Land | 105 | 90 |
I calculate the ONI each week using a method that I have devised. To refine my calculation, I have divided the 170W to 120W ONI 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 February 29 in the afternoon working from the February 28 TAO/TRITON report, this is what I calculated.
Anomaly Segment | Estimated Anomaly | |
Last Week | This Week | |
A. 170W to 160W | 1.9 | 1.9 |
B. 160W to 150W | 2.2 | 2.1 |
C. 150W to 140W | 2.4 | 2.1 |
D. 140W to 130W | 2.1 | 2.0 |
E. 130W to 120W | 1.9 | 1.9 |
Total | 10.5 | 10.0 |
Total divided by five subregions i.e. the ONI | (10.5)/5 =2.1 | (10.0)/5=2.0 |
The full history of the ONI readings can be found here. The MEI index readings can be found here.
Is this El Nino a Modoki?
It did not evolve as a Modoki unless you consider it to be a continuation of the Faux El Nino Modoki of 2014/2015 which is a possible interpretation. But the Walker Circulation appears to be much like that of a Modoki. These graphics help explain this.
Although I discussed the Kelvin Waves earlier, now seems to be the best place to show the evolution of the subsurface temperatures.
Watching an El Nino evolve is like watching paint dry. The undercutting cool anomaly which had withdrawn to the west quite a bit is again expanding to the east and again quite rapidly basically arriving at 130W which means it has undercut essentially all of the NINO 3.4 Measurement Area. All that remains is for “The Grand Switch” to occur with the cool anomaly reversing positions with the warm anomaly. This El Nino does not appear to be willing to just give up however. The weak area over by 100W which last week had filled in with cold anomaly water at the surface with warmer anomaly water below again looks like it is getting ready to fully separate from the coastal warm anomaly. So either this will be a slow process or some event will just flush the warm water to the west. It may be the next Inactive Phase of the MJO that does just that and that is just two to three weeks from now. It is just a matter of time and watching more paint dry.
SST Surface Anomaly Hovmoeller
Here is another way of looking at it: Unlike the Upper Ocean Heat Anomaly Hovmoeller (I call it the Kelvin Wave Hovmoeller) which takes an average down to 300 meters, this just measures the surface temperature anomaly. It is the surface that interacts with the atmosphere. 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. Nevertheless this Hovmoeller provides a good way to visually see the evolution of this El Nino and later track its demise.
Recent Impacts of Weather Mostly El Nino but possibly Also PDO and AMO Impacts.
Below are snapshots of 30 Day temperature and precipitation departures over the life of this El Nino. The end date of the 30 day period is shown in the graphic. It is a way of seeing how the impacts of this El Nino have unfolded.
Remember this is a 30 day average and only seven days were added and seven days were removed. The La Nina pattern persists for the West with respect to both precipitation and temperature. The East is a bit like an El Nino.
I realize this is a lot of graphics but one needs to look at the history of an event to assess it. As you can see, so far we are not having the expected El Nino Impacts in CONUS.
El Nino in the News
Nothing to report this week.
View from Australia
El Nino
Here is the discussion just released:
El Niño continues to influence global climate as it weakens
Issued on 1 March 2016
The 2015–16 El Niño is now at moderate levels, and is likely to end in the second quarter of 2016. History and model outlooks indicate that neutral conditions are slightly favoured ahead of La Niña for the second half of 2016. Short term fluctuations in the various El Niño Indicators will continue, particularly during the southern tropical cyclone season.
The past fortnight has seen sea surface and below-surface cooling in the central tropical Pacific Ocean. The Nino3.4 index, a key El Niño Indicator, is now below +2 °C for the first time since September 2015, suggesting moderate El Niño levels. Likewise, the Southern Oscillation Index remains negative at moderate levels. A recent temporary weakening of the trade winds has only slightly slowed the decline of El Niño
Although the 2015–16 El Niño is weakening, it will continue to influence global climate during the southern hemisphere autumn. In Australia, the breakdown of strong El Niño events has historically brought average to above average rainfall to many locations. However, northern Australia typically sees less rainfall than usual.
Australia’s climate is also being influenced by record warm temperatures in the Indian Ocean. The warmth in the Indian Ocean may provide extra moisture for rain systems as they cross Australia during the southern autumn.
Next update expected on 15 March 2016
IOD (Indian Ocean Dipole)
The graphic comes with only a very short discussion and here is that discussion:
The Indian Ocean Dipole (IOD) is neutral. The Dipole Mode Index value to 28 February was −0.26 °C. The IOD does not typically influence Australian climate during the months December to May, when the monsoon trough is in the southern hemisphere (as positive and negative events are not typically able to form in monsoonal flow).
More generally, sea surface temperatures (SSTs) remain significantly warmer than average across most of the Indian Ocean basin, with a large part of the Indian Ocean measuring warmest on record for January 2016. This unusually warm ocean is likely to increase the available moisture for weather systems travelling across Australian in the coming weeks and months, increasing the likelihood of good falls occurring across southern Australia during autumn.
The interrelationship between the IOD and El Nino is complicated and not fully understood. A negative IOD is less frequently discussed. Here is the explanation from the Australian Bureau of Meteorology. Notice that since 1958, four of the negative IOD’s occurred during La Nina conditions and five of the negative IOD’s occurred during ENSO Neutral Conditions.
Putting it all Together.
This El Nino has peaked in intensity and is now in rapid decline. We are beginning to speculate on the winter of 2016/2017 which now according to the models seems increasingly likely to be a La Nina.
The below is the CPC/IRI forecast issued on February 18, 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.
We have suggested that it is possible the models 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.
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.
TABLE OF CONTENTS FOR PART II OF THIS REPORT 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.
A. Worldwide Weather: Current and Three-Month Outlooks: 15 Month Outlooks (Usefully bookmarked as it provides automatically updated current weather conditions and forecasts at all times. It does not replace local forecasts but does provide U.S. national and regional forecasts and, with less detail, international forecasts)
B. Factors Impacting the Outlook
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.
C. Computer Models and Methodologies
D. Reserved for a Future Topic (Possibly Predictable Economic Impacts)
TABLE OF CONTENTS FOR PART 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.
D2. Climate Impacts of Global Warming
D3. Economic Impacts of Global Warming
D4. Reports from Around the World on Impacts of Global Warming