NOAA’s NEW GLOBAL CLIMATE FORECAST SYSTEM INCREASES CONFIDENCE THAT WEAK EL NIÑO CONDITIONS ARE DEVELOPING

Aug. 24, 2004 — NOAA scientists are becoming increasingly confident weak El Niño conditions are developing in the tropical Pacific, based in part on a new Climate Forecast System that became operational Tuesday. The Climate Forecast System was developed at the NOAA Environmental Modeling Center in collaboration with NOAA Research. (Click NOAA image for larger view of new Climate Forecast System forecast of the developing El Niño in the Eastern Pacific Ocean. Click here for high resolution version, which is a large file. Please credit “NOAA.”)

“NOAA expects weak El Niño conditions to develop by the end of August," said retired Navy Vice Adm. Conrad C. Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. "The Climate Forecast System complements our other models and gives NOAA increased confidence that weak El Niño conditions will develop in the central Pacific.” However, at this time it is not clear what, if any, impacts this event will have on ocean temperatures in the classical El Niño region along the west coast of South America. “Presently, NOAA does not anticipate significant impacts from this potential El Niño in the U.S.,” he added.

Under development for a year by a team of NOAA scientists, the Climate Forecast System is a coupled model approach, representing the interaction between the Earth's oceans and the atmosphere. These interactions are critical for determining climate on seasonal time scales.

“The system is already pushing the boundaries of science and effectively complementing NOAA’s existing seasonal forecasting process,” said retired Air Force Brig. Gen. David L. Johnson, director of the NOAA National Weather Service. “The Environmental Modeling Center is an important part of the National Weather Service mission in that they develop numerical models that provide climate, weather and water products and services for America. The new Climate Forecast System is the beginning of a new era for climate forecasting, leading to potential improvements in U.S. seasonal outlooks.”

These outlooks provide guidance to customers in various economic sectors, including agriculture, energy, water resources, transportation and the financial markets, on national weather well in advance of a particular season.

“The Climate Forecast System is the first fully global coupled prediction system developed at NOAA that produces a set of operational seasonal forecasts using an interactive ocean-land-atmosphere system,” said Hua-Lu Pan, EMC’s climate modeling team leader. “This system attempts to more accurately depict the actual physical processes that occur in nature.”

Historically, operational climate forecasts have relied mostly on the knowledge of present and past conditions to make projections about future events. Current methods are based largely on statistical relationships and the physical laws that govern climate. Now, armed with the Climate Forecast System, NOAA scientists are using improved dynamic methods to predict the future behavior of the climate, which entails solving extremely complex mathematical equations on the NOAA weather and climate supercomputer.

NOAA declares the onset of El Niño conditions when the three-month average sea-surface temperature departure exceeds 0.5 degrees C in the east-central equatorial Pacific [between 5 degrees –5 degrees S and 170 degrees W-120 degrees W]. To be classified as a full-fledged El Niño episode, these conditions must be satisfied for a period of at least five consecutive three-month seasons.

El Niño and its sister La Niña are associated with changes in sea surface temperatures in the tropical Pacific Ocean and can have significant impacts on weather around the world, including the United States. El Niño episodes occur about every four to five years and can last up to 12 to 18 months.

NOAA will continue monitoring El Niño developments and provide monthly updates. NOAA will update its El Niño/Southern Oscillation (ENSO) Diagnostic Discussion and Outlook on September 9, 2004.

NOAA is dedicated to enhancing economic security and national safety through the prediction and research of weather and climate-related events and providing environmental stewardship of the nation�s coastal and marine resources. NOAA is part of the U.S. Department of Commerce.

Relevant Web Sites
NOAA El Ni�o/Southern Oscillation (ENSO) Discussion

NOAA El Ni�o/La Ni�a Page

NOAA Climate Prediction Center

NOAA Environmental Modeling Center

NOAA Gets U.S. Consensus for El Niño/La Niña Index, Definitions

Media Contact:
Carmeyia Gillis, NOAA Climate Prediction Center, (301) 763-7000 ext. 7163