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:
“Recent observations show weak signs of La Niña. The SINTEX-F ensemble mean predicts that a weak La Niña Modoki will develop during the boreal winter, but there is uncertainty in the timing and amplitude of the event. The tropical Pacific will then be in a neutral state during the boreal spring and summer.”
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 when we publish it.
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 November 12, 2024 which is before NOAA has issued their four-season update this month. The JAMSTEC model runs are based on conditions as of November 1, 2024. The NOAA Seasonal Outlook is based on conditions closer to the time when it will be issued.
We have a full three-season forecast from JAMSTEC this month. We have forecast maps for DJF, MAM and JJA so it is really a three season forecast.
We also have single-month JAMASTEC forecasts for December 2025 through May 2025 . I do not have the NOAA four season outlook yet so I could not do the comparisons but I might try doing that when the NOAA four-season Outlook is published.
| This shows their forecast of sea surface temperature anomalies at three points in time. Blue is a cold anomaly and is associated with La Nina if it occurs in the Nino 3.4 measurement areas in the Pacific along the Equator. The cool anomaly along the Equator is somewhat further west than usual which gives it the Modoki characteristics.
The U.S. funded some of the Modoki research but for some reason declines to mention it in their seasonal outlook discussions. In the DJF image above, look at that blob of cool (anomaly) water to the west along the Equator. Thus the La Nina has Modoki characteristics that impact the Walker circulation. 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. It was also discussed in the most recent ENSO Update in the article by Emily Becker. That article can be accessed HERE. Of interest also is the neutrally cold water just off the West Coast of the U.S. and the warm water between Africa and the north coast of South America which can support tropical storms and hurricanes. NOAA publishes a similar SSTA analysis. It can be accessed HERE. 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. |
This month we have the JAMSTEC three-season forecast before the NOAA four-season forecast was issued. We will do the comparisons in the article on the NOAA four-season forecast.
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.
Then we look at three forecasts. As discussed earlier, JAMSTEC tries to work with meteorological seasons and this month it lines up perfectly since we have DJF, MAM and JJA.
Now we look at the three three-month forecasts that were provided.
| The above covers December/January/February 2024-2025 which is Winter
“The model predicts warmer than normal conditions for most of the globe during the boreal winter, except for some parts of Alaska, western Canada, Central America, some parts of the South American continent, Saudi Arabia, southern India, Indochina, southern China, some parts of Indonesia, northern/central Africa, the Mediterranean basin, and eastern Siberia. Colder than normal conditions are predicted for some parts of Alaska, northern Canada, India, and eastern Siberia. ” “For the boreal winter mean precipitation, drier-than-normal conditions are predicted for some parts of the United States, some parts of Mexico, the La Plata Basin, some parts of southern Africa, some parts of Indonesia, and eastern China. On the other hand, wetter-than-normal conditions are predicted for southern Alaska, some parts of Canada, some parts of the United States, some parts of Central America, the Caribbean, northern South America, the western Pacific Islands, northern New Zealand, northern Australia, Mozambique, Madagascar, some parts of the Philippines, some parts of Indonesia, Malaysia, and some parts of Norway. ” “The model predicts that most of Japan will experience milder winter and some parts of eastern Japan (Kyushu and Okinawa) will be wetter (drier) than normal.” |
| The above covers March/April, May 2025 which is Spring.
Here is the interpretation from the JAMSTEC discussion: “During the boreal spring, the model predicts warmer than normal conditions for most of the globe, except for western Canada, Central America, most of the South American continent, northern Australia, India, Indochina, southern China, some parts of Indonesia, northern/central Africa, and some parts of southern Africa. Colder than normal conditions are predicted for Alaska, some parts of northern Canada, and some parts of Vietnam.” “During the boreal spring, drier-than-normal conditions are predicted for the United States, Mexico, the La Plata Basin, Nepal, Bhutan, some parts of Indonesia, northern Papua New Guinea, some parts of central Asia, eastern China, and Taiwan. On the other hand, wetter-than-normal conditions are predicted for some parts of Canada, some parts of Central America, northern South America, the western Pacific Islands, northern Australia, some parts of southern Africa, the southern part of the Philippines, Indochina, some parts of China, some parts of Indonesia, and some parts of Norway.” “During the boreal spring, the model predicts that most of Japan will be warmer than normal and Hokkaido (western Japan) will be wetter (drier) than normal.” |
| The above covers June/July/August which is Summer.
JAMSTEC does not provide a commentary for the third season map but the reader can interpret it themselves.
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Now I am going to provide their single-month forecasts for December 2024 and January, February, March, April, and May 2025.
| The above is the single month of December 2024. It is interesting as a world forecast but since the U.S. is part of the world it also provides a U.S. forecast. |
| The above is the single month of January 2025. |
| The above is the single month of February 2025. |
| The above is the single month of March 2025. |
| The above is the single month of April 2025. |
| The above is the single month of May 2025. |
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 marginal and shorter La Nina which is different from what NOAA is forecasting. |
| I am showing the Modoki Index this month. It is a bit different than the Nino 3.4 index but not by very much. |
And here is the short JAMSTEC Discussion which I have already included with each of the seasonal forecast maps.
ENSO forecast:
Recent observations show weak signs of La Niña. The SINTEX-F ensemble mean predicts that a weak La Niña Modoki will develop during the boreal winter, but there is uncertainty in the timing and amplitude of the event. The tropical Pacific will then be in a neutral state during the boreal spring and summer.
Indian Ocean forecast:
A higher than normal temperature is present in the tropical Indian Ocean, indicating a positive phase of the Indian Ocean Basin Mode (IOBM). Meanwhile, warmer temperatures in the east indicate the development of a negative phase of the Indian Ocean Dipole (IOD). The SINTEX-F predicts that the positive phase of the IOBM/the negative phase of the IOD will weaken during the boreal fall, and then the tropical Indian Ocean will be in a neutral state during the boreal winter.
Regional forecast:
The model predicts warmer than normal conditions for most of the globe during the boreal winter, except for some parts of Alaska, western Canada, Central America, some parts of the South American continent, Saudi Arabia, southern India, Indochina, southern China, some parts of Indonesia, northern/central Africa, the Mediterranean basin, and eastern Siberia. Colder than normal conditions are predicted for some parts of Alaska, northern Canada, India, and eastern Siberia. During the boreal spring, the model predicts warmer than normal conditions for most of the globe, except for western Canada, Central America, most of the South American continent, northern Australia, India, Indochina, southern China, some parts of Indonesia, northern/central Africa, and some parts of southern Africa. Colder than normal conditions are predicted for Alaska, some parts of northern Canada, and some parts of Vietnam.
For the boreal winter mean precipitation, drier-than-normal conditions are predicted for some parts of the United States, some parts of Mexico, the La Plata Basin, some parts of southern Africa, some parts of Indonesia, and eastern China. On the other hand, wetter-than-normal conditions are predicted for southern Alaska, some parts of Canada, some parts of the United States, some parts of Central America, the Caribbean, northern South America, the western Pacific Islands, northern New Zealand, northern Australia, Mozambique, Madagascar, some parts of the Philippines, some parts of Indonesia, Malaysia, and some parts of Norway. During the boreal spring, drier-than-normal conditions are predicted for the United States, Mexico, the La Plata Basin, Nepal, Bhutan, some parts of Indonesia, northern Papua New Guinea, some parts of central Asia, eastern China, and Taiwan. On the other hand, wetter-than-normal conditions are predicted for some parts of Canada, some parts of Central America, northern South America, the western Pacific Islands, northern Australia, some parts of southern Africa, the southern part of the Philippines, Indochina, some parts of China, some parts of Indonesia, and some parts of Norway.
The model predicts that most of Japan will experience milder winter and some parts of eastern Japan (Kyushu and Okinawa) will be wetter (drier) than normal. During the boreal spring, the model predicts that most of Japan will be warmer than normal and Hokkaido (western Japan) will be wetter (drier) than normal.
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| I hope you found this article interesting and useful |
