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Our Report on the JAMSTEC Three-Season Forecast – Posted on June 22, 2024

By Sig Silber June 22, 2024weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

“The most recent observations indicate that the El Niño is now almost over, and there are weak signs of a La Niña. The SINTEX-F ensemble mean predicts that a La Niña Modoki will develop in the boreal autumn. However, there is a large uncertainty in the occurrence timing and amplitude.”

Although it is a World forecast, it includes a forecast for North America since North America is part of the World. One might try to compare it to the NOAA Outlook we published yesterday which can be accessed HERE.

First, we take a look at the forecasted sea surface temperature anomalies (SSTA). JAMSTEC starts by forecasting the SSTA and Nino 3.4 Index on the first day of the month and from there it usually takes their models about two weeks to produce their seasonal forecast. I received it from JAMSTEC on May 14 close to when NOAA issued their Seasonal Update this month. The JAMSTEC model runs are based on conditions as of June 1, 2024. The NOAA Seasonal Outlook is based on conditions closer to the time when it was issued.

We do not have a full three-season forecast from JAMSTEC this month. We have forecast maps for JAS, SON and DJF so it is really an eight-month forecast as JAS and SON overlap a bit. For each of these three-month Outlooks, I also show the corresponding NOAA Outlook. The two are remarkably similar which is very unusual.

We also have single-month forecasts for July, August and September 2024. I have a single-month outlook for July from NOAA but not single-month outlooks for August and September so I did not show those comparisons.

Let’s take a look.

This shows their forecast of sea surface temperature anomalies at three points in time. Blue is cold and is associated with La Nina if it occurs in the Nino 3.4 measurement areas. You no longer can see the El Nino tongue of warm water extending from Peru to the west in the JAS image but look at that blob of cool (anomaly) water to the west i.e. by this point in time this has Modoki characteristics that impact the Walker circulation. SON and DJF also show La Nina but are increasingly to the west and may not be in the Nino 3.4 measurement area. I have written about that before. It raises questions about the reliability of our current approach to thinking about the ENSO Cycle. This is covered in another article that can be accessed HERE. But JAMSTEC is showing a relatively normal ocean off the coast of much of the U.S. coasts which probably explains their forecast.

Of interest also is the cold water of the West Coast of the U.S. and the warm water between Africa and the north coast of South America.

JAMSTEC uses the same definition of Normal (climatology) as NOAA. JAMSTEC does a better job at characterizing La Ninas and El Ninos than NOAA. JAMSTEC provides me with a lot of other information that I do not include in my articles to keep them to a manageable size for readers. That material is the atmospheric pressure patterns.

Some Readers will have to click on “Read More” to read the rest of the article which you need to read to see the forecasts. I can only include a certain amount of material in the lede.

Our Report on the JAMSTEC Three-Season Weather Forecast – October 21, 2023

By Sig Silber October 21, 2023weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

As predicted, the recent observation confirms further development of the El Niño. The SINTEX-F ensemble mean predicts that the El Niño will reach its peak in the boreal winter and persist at least until the next boreal spring. However, there is a large uncertainty in the predicted amplitude.

Although it is a World forecast, it includes a forecast for North America since North America is part of the World. The JAMSTEC discussion does not address it but the maps show the U.S. being an area that has a lot of area that is not warmer than Climatology which I interpret as a fairly cold winter but surprisingly dry in the Southwest.

First, we take a look at the forecasted sea surface temperature anomalies (SSTA). JAMSTEC starts by forecasting the SSTA and Nino 3.4 Index on the first day of the month and from there it usually takes their models about two weeks to produce their seasonal forecast. I received it from JAMSTEC on October 20, 2023 which is when NOAA issued their Seasonal Update. The JAMSTEC model runs are based on conditions as of October 1, 2023. The NOAA Seasonal Outlook was based on conditions closer to the time when it is issued.

We do not have a three-season forecast from JAMSTEC this month. We have three forecasts but the first covers NDJ and the second covers DJF so they are just a month apart. This is because JAMSTEC prefers to work with the Meteorological Seasons so we have Winter and Spring and the first map which is one month of Autumn with two months of winter so they are very similar.

One might question their winter forecast for the Southwest but it is somewhat consistent with the below.

JAMSTEC (and also NOAA) are showing very warm oceans. I have written about that before. It raises questions about the reliability of our current approach to thinking about the ENSO Cycle. This is covered in another article that can be accessed HERE. But JAMSTEC is showing a relatively normal ocean off the coast of much of the U.S. which probably explains their strange forecast.

JAMSTEC uses the same definition of Normal (climatology as NOAA). They do a better job at characterizing La Ninas and El Ninos than NOAA. JAMSTEC provides me with a lot of other information that I do not include in my articles to keep them to a manageable size for readers.

Our Report on the JAMSTEC Three-Season Weather Forecast – August 26, 2023

By Sig Silber August 26, 2023weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

As predicted, the recent observation confirms the development of the El Niño. The SINTEX-F ensemble mean predicts that the El Niño will reach its peak in the boreal autumn and persist at least until the next boreal spring. However, there is a large uncertainty in the predicted amplitude.

Although it is a World forecast, it includes a forecast for North America since North America is part of the World.

First, we take a look at the forecasted sea surface temperature anomalies (SSTA). JAMSTEC starts by forecasting the SSTA and Nino 3.4 Index on the first day of the month and from there it usually takes their models about two weeks to produce their seasonal forecast. I received it from JAMSTEC on August 22, 2023 which was later than usual. That is important because the model runs are based on conditions as of August 1.

Both NOAA and JAMSTEC are showing very warm oceans. I have written about that before. It raises questions about the reliability of our current approach to thinking about the ENSO Cycle. This is covered in another article that can be accessed HERE.

Then we look at three forecasts. JAMSTEC tries to work with meteorological seasons and this month it lines up perfectly and we have three full-season forecasts.

Now we look at the three seasonal forecasts.

The above covers September/October/November (SON 2023) also known as meteorological Autumn.

Here is the interpretation from the JAMSTEC Discussion shown in the body of the article:

“The SINTEX-F predicts that most parts of the globe will experience a hotter-than-normal condition in the boreal autumn (austral spring). The Arctic region will experience extremely hotter-than-normal conditions. ”

“As regards the rainfall in the boreal autumn (austral spring), a drier-than-normal condition is predicted for some parts of the U.S.A., Hawaii, the northern part of the South American continent, eastern Australia, Uganda, Tanzania, Indonesia, some parts of Indochina, and the Philippines. In contrast, southern Alaska, the Caribbean, La Plata, some parts of India, Sri Lanka, Nepal, Bhutan, central and western Africa, the Horn of Africa, and some parts of East Asia will experience a wetter-than-normal condition. In particular, we notice that Indonesia and eastern Australia may experience extremely drier than normal conditions, owing to a combination of the positive Indian Ocean Dipole and the El Niño. ”

“The model predicts that most of Japan will be warmer than normal in the autumn. The model also predicts that western Japan will be wetter than normal in the autumn.”

The above covers December/January/February (DJF 2023-2024) which is meteorological Winter.

Here is the interpretation from the JAMSTEC Discussion shown below:

“The model also predicts a similar condition (to autumn) in the boreal winter (austral summer).

“In the boreal winter (austral summer), a drier-than-normal condition is predicted for the western coastal areas of Canada and the northern U.S.A., Hawaii, Brazil, some parts of the South American continent, northern Australia, the Philippines, and southern Africa. In contrast, Alaska, some parts of the U.S.A., some parts of La Plata, central and eastern Africa, Madagascar, some parts of Central and East Asia, and some parts of Indonesia will experience a wetter-than-normal condition.”

“The model predicts that most of Japan will be warmer than normal in the winter. The model also predicts that western Japan will be wetter than normal in the winter.”

And above, March/April/May (MAM) 2024 is meteorological Spring. JAMSTEC does not provide its interpretation of its third season but one can observe it on the maps.

Our Report on the JAMSTEC Three-Season Forecast – July 16, 2023

By Sig Silber July 16, 2023weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

As predicted, the recent observation confirms the development of the El Niño. The SINTEX-F ensemble mean predicts that the El Niño will reach the peak in August and persist at least until the next boreal spring. However, there is a large uncertainty in the predicted amplitude.

Although it is a World forecast, it includes a forecast for North America since North America is part of the World.

First, we take a look at the forecasted sea surface temperature anomalies (SSTA). JAMSTEC starts by forecasting the SSTA and Nino 3.4 Index on the first day of the month and from there it takes their models about two weeks to produce their seasonal forecast. I received it from JAMSTEC on July 13, 2023.

This shows their forecast of sea surface temperature anomalies at three points in time. Red is warm and is associated with El Nino. You can see the El Nino tongue of warm water extending from Peru to the west in all three time periods. It seems to be stronger in the 1st and 2nd time periods. The warmest water shifts west in the third period exhibiting Modoki characteristics. [I have similar information on their SSTA projections from NOAA but I usually do not include it in the article I write on the NOAA Seasonal Outlook because they do not seem to focus on it and their information does not extend as far into the future as does the information from JAMSTEC]. It is hard to find any blue in this set of forecasts but there is a bit of blue off of Baja California which is interesting. JAMSTEC uses the same definition of Normal (climatology as NOAA). They do a better job at characterizing La Ninas and El Ninos than NOAA. JAMSTEC provides me with a lot of other information that I do not include in my articles to keep them to a manageable size for readers. Yesterday we published the NOAA ENSO Advisory and our article can be accessed HERE. In that article, Emily Becker commented on the generally warm oceans and how this may make predicting the strength and duration of an El Nino difficult.

Then we look at three forecasts. JAMSTEC tries to work with meteorological seasons and this month it does not line up perfectly. This means we do not have three full seasons of forecasts this month because the first three-month period overlaps the second one. ASO is one month of meteorological summer and two months of Autumn and SON is autumn. So we really have autumn and winter (DJF) with a forecast that is the transition to autumn.

NOAA Updates its ENSO Alert on July 13, 2023 – El Nino is here and 90% Likely to Last through Winter with a 20% Chance of a MegaNino

By Sig Silber July 15, 2023weatherNo Comments

On the second Thursday of every month, NOAA issues its analysis of the status of ENSO. This includes determining the Alert System Status. NOAA again describes their Report as “ENSO Alert System Status: El Nino Watch”

There is not much doubt that we have an El Nino. How long it lasts and its strength remains to be seen.

From the NOAA Analysis:

CLIMATE PREDICTION CENTER ENSO DISCUSSION

The second paragraph is what is important:

“The most recent IRI plume indicates El Niño will persist through the Northern Hemisphere winter 2023-24. Forecasters favor continued growth of El Niño through the fall, peaking this winter with moderate-to-strong intensity (81% chance of November-January Niño-3.4 ≥1.0C). An event that becomes “historically strong” (seasonally averaged Niño-3.4 ≥ 2.0C), rivaling the winters of 1997-98 or 2015-16, has an approximately 1 in 5 chance. In summary, there is a greater than 90% chance that El Niño will continue through the Northern Hemisphere winter.

We now provide additional detail.

CPC Probability Distribution

Here are the new forecast probabilities. This information in the past has been released twice a month and the first release is based on a survey of Meteorologists, the second is based on model results. The probabilities are for three-month periods e.g. JJA stands for June/July/August. The first forecast forecast is used to develop the Seasonal Outlook which will be issued next Thursday so that is what I am focusing on.

Here is the current release of the probabilities:

You can clearly see The forecast does not extend beyond FMA 2024 but one does see a slight tail-off in the probabilities for El Nino conditions in the Eastern Pacific after the winter season.

Our Report on the JAMSTEC Three-Season Forecast – June 16, 2023

By Sig Silber June 16, 2023weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

“As predicted, the recent observation confirms the occurrence of an El Niño. The SINTEX-F ensemble mean predicts that the El Niño will continue to develop in June–July, mature in August, and persist at least until the next boreal spring.” [JAMSTEC predicts an El Nino that is weaker than forecast by NOAA and most other Meteorological Agencies]

Although it is a World forecast, it includes a forecast for North America since North America is part of the World.

Our Report on the JAMSTEC Three-Season Forecast – May 15, 2023

By Sig Silber May 15, 2023weatherNo Comments

The Japan Agency for Marine-Earth Science and Technology, or JAMSTEC, is a Japanese national research institute for marine-earth science and technology

From the JAMSTEC Discussion:

“Observation shows that the La Niña Modoki-like state persists. The SINTEX-F ensemble mean predicts that an El Niño will occur in June. However, there is a large uncertainty in the predictions of the amplitude, and the ensemble mean of the SINTEX-F2-3DVAR version predicts a relatively weak El Niño.” [This puts JAMSTEC in disagreement with NOAA and most other Meteorological Agencies]

Although it is a World forecast, it includes a forecast for North America since North America is part of the World.

NOAA Updates its ENSO Alert on May 11, 2023 – El Nino now 90% Likely

By Sig Silber May 12, 2023weatherNo Comments

Lightly Edited at 9:39 p.m. Saturday, May 12, 2023 to add some details that I was too exhausted to sort out when I published early this morning.

There is not much doubt that we will have an El Nino.

From the NOAA Analysis:

The combination of a forecasted third westerly wind event in mid-late May, and high levels of above-average oceanic heat content, means that a potentially significant El Niño is on the horizon. While at least a weak El Niño is likely, the range of possibilities at the end of the year (November-January) include a 80% chance of at least a moderate El Niño (Niño-3.4 greater than or equal to 1.0°C) to a ~55% chance of a strong El Niño (Niño-3.4 greater than or equal to 1.5°C). It is still possible the tropical atmosphere does not couple with the ocean, and El Niño fails to materialize (5-10% chance).

Two Multi-seasonal Weather Outlooks: NOAA and JAMSTEC April 22, 2023

By Sig Silber April 22, 2023weatherNo Comments

Some additional light editing at 5:03 p.m EDT Sunday April 23, 2023 to explain a difference in the way the two agencies present information.

Here we present two multi-season weather outlooks.

NOAA provides such an outlook for the U.S. every month and JAMSTEC does so for the World. Their world outlook of course includes the U.S. I used to compare the two. The reader can do this themselves.

The JAMSTEC forecast is of interest partly because both Japan and the US. have weather that is mostly based on the Pacific Ocean.

NOAA Updates its ENSO Alert Status to El Nino Watch on April 13, 2023

By Sig Silber April 14, 2023weatherNo Comments

Additional editing at 11:01 p.m. EDT April 14, 2023. I noticed that a map had dropped out of the article so I replaced it and I expanded the discussion blocks. I moved some graphics around. It will be easier to read now. While preparing the article I had not realized the extent of the changes. So I have better highlighted those changes now.

On the second Thursday of every month, NOAA issues its analysis of the status of ENSO. This includes determining the Alert System Status. NOAA describes their Report as “ENSO Alert System Status: El Nino Watch”

If you read the fine print you can see that

“While the lower accuracy of forecasts during the spring can result in surprises, the recent oceanic Kelvin wave plus recurring westerly wind anomalies are anticipated to further warm the tropical Pacific Ocean. The coastal warming in the eastern Pacific may foreshadow changes across the Pacific basin. Therefore, an El Niño Watch has been issued, and the range of possibilities toward the end of the year includes a strong El Niño (4 in 10 chance of Niño-3.4 ³ 1.5°C) to no El Niño (1 in 10 chance). In summary, ENSO-neutral conditions are expected to continue through the Northern Hemisphere spring, followed by a 62% chance of El Niño developing during May-July 2023.”

The article includes two very interesting posts from the ENSO Blog. They are worth reading.