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.
| 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 which overlap a lot. The warmest water shifts was bit west in the third period exhibiting some Modoki characteristics.
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. |
Then we look at three forecasts. As discussed earlier, JAMSTEC tries to work with meteorological seasons and this month it does not line up perfectly so there is overlap among the first two three-month forecasts. The second and third cover meteorological seasons and the first one overlaps the second a lot since we are in November almost out of Meteorological Autumn/Fall.
Now we look at the three seasonal forecasts.
| The above covers November/ December/January (NDJ 2023-2024)
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 November–January, except for most of the U.S.A and La Plata. The Arctic region will experience extremely hotter-than-normal conditions. The model also predicts a similar condition in the boreal winter (austral summer). As regards the rainfall in November–January, a drier-than-normal condition is predicted for a western coastal part of the U.S.A., Hawaii, some parts of the Caribbean, Brazil, some parts of the South American continent, northern/eastern Australia, northern part of New Zealand, Tanzania, Malawi, Mozambique, an eastern part of South Africa, Indonesia, and the Philippines. In contrast, Alaska, an eastern part of the U.S.A., Colombia, Ecuador, La Plata, Sri Lanka, Nepal, Bhutan, central Africa, Kenya, western Europe, some parts of Indochina, and most of East Asia will experience a wetter-than-normal condition. In particular, we notice that Indonesia and northern/eastern Australia may experience extremely drier than normal conditions, owing to a combination of the positive Indian Ocean Dipole and the El Niño. It may increase the likelihood of bushfires in the countries in the coming season. Also, the positive Indian Ocean Dipole will be responsible for flooding in East African countries such as Kenya.” “The model predicts that most of Japan will be warmer and wetter than normal in the autumn and winter.” |
| The above covers December/January/February (DJF 2023-2024) which is meteorological Winter.
Here is the interpretation from the JAMSTEC Discussion shown below: “In the boreal winter (austral summer), a drier-than-normal condition is predicted for the western coastal areas of the U.S.A., Hawaii, northern Brazil, some parts of the South American continent, northern/eastern Australia, the Philippines, Tanzania, Malawi, Mozambique, and an eastern part of South Africa. In contrast, southern Alaska, a southeastern part of the U.S.A., southern Brazil, Colombia, Ecuador, some parts of La Plata, central Africa, Nepal, Bhutan, some parts of Indonesia, and most of East Asia will experience a wetter-than-normal condition.” [Editor’s note: JAMSTEC is talking about almost the same time period as in the prior discussion above] “The model predicts that most of Japan will be warmer and wetter than normal in the autumn and winter.” |
| JAMSTEC does not provide a commentary for the third map but the reader can interpret it themselves. |
Now I am going to provide their single-month forecasts for November, December, and January.
| The above is the single month of November 2023. It is a world forecast but you can clearly see the forecast for the U.S. One can see some cool areas in the U.S. (think snow) and a very wet Southeast and East Coast. Brazil may have a large area of drought. |
| The above is the single month of December 2023. The cool area expands in the U.S. Remember that “normal” is cool relative to recent years. |
| The above is the single month of January 2024. We still see an area in the Southeast forecast to be wet but it is smaller than in November and December. |
Now we look at the key indices used by JAMSTEC in making their forecast. Perhaps I should have presented these first.
| This forecast is for a fairly strong El Nino (Nino 3.4 peaking at 2.0). It is forecasting a fairly rapid decline in the strength of the El Nino 3.4 Index. |
| I am showing the Modoki Index this month. As we move from winter to spring the Modoki Index suggests some shifting to the west of the Walker Circulation. |
| We are having a Positive IOD but it will end fairly soon. Below is shown the typical impact of a positive IOD. But the impacts can be complex. It may appear again next year but so far that part of the graph is not very convincing and there is a lot of spread in the forecasts. |
And here is the short JAMSTEC Discussion
ENSO forecast:
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.
Indian Ocean forecast:
As predicted, the recent observation confirms the development of the positive Indian Ocean Dipole event. The SINTEX-F predicts that the positive Indian Ocean Dipole will reach its peak in October and decay in the boreal winter. However, the model predicts that the warmer-than-normal temperature in the western Indian Ocean will persist through the boreal winter.
Regional forecast:
The SINTEX-F predicts that most parts of the globe will experience a hotter-than-normal condition in November–January, except for most of the U.S.A and La Plata. The Arctic region will experience extremely hotter-than-normal conditions. The model also predicts a similar condition in the boreal winter (austral summer).
As regards the rainfall in November–January, a drier-than-normal condition is predicted for a western coastal part of the U.S.A., Hawaii, some parts of the Caribbean, Brazil, some parts of the South American continent, northern/eastern Australia, northern part of New Zealand, Tanzania, Malawi, Mozambique, an eastern part of South Africa, Indonesia, and the Philippines. In contrast, Alaska, an eastern part of the U.S.A., Colombia, Ecuador, La Plata, Sri Lanka, Nepal, Bhutan, central Africa, Kenya, western Europe, some parts of Indochina, and most of East Asia will experience a wetter-than-normal condition. In particular, we notice that Indonesia and northern/eastern Australia may experience extremely drier than normal conditions, owing to a combination of the positive Indian Ocean Dipole and the El Niño. It may increase the likelihood of bushfires in the countries in the coming season. Also, the positive Indian Ocean Dipole will be responsible for flooding in East African countries such as Kenya.
In the boreal winter (austral summer), a drier-than-normal condition is predicted for the western coastal areas of the U.S.A., Hawaii, northern Brazil, some parts of the South American continent, northern/eastern Australia, the Philippines, Tanzania, Malawi, Mozambique, and an eastern part of South Africa. In contrast, southern Alaska, a southeastern part of the U.S.A., southern Brazil, Colombia, Ecuador, some parts of La Plata, central Africa, Nepal, Bhutan, some parts of Indonesia, and most of East Asia will experience a wetter-than-normal condition.
The model predicts that most of Japan will be warmer and wetter than normal in the autumn and winter.
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| I hope you found this article interesting and useful |
