Our Report on the JAMSTEC Three-Season Forecast – Posted on May 18, 2024
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 has further weakened, and a weak indication of a La Niña is emerging. The SINTEX-F ensemble mean predicts that the El Niño will continue to decay and 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 May 1, 2024. The NOAA Seasonal Outlook is based on conditions closer to the time when it is issued.
We have a full three-season forecast from JAMSTEC this month. We also have single-month forecasts for June, July, and August 2024.
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 JJA image but look at that blob of cool (anomaly) water to the west i.e. by this point in time this has Modoki characteristics which impact the Walker circulation. JJA and SON 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.
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. |