February 5, 2009
Pacific Sea Surface Temperature Animation (Nov. 12, 2008 to Jan. 28, 2009).
High resolution (Credit: NOAA)
NOAA’s Climate Prediction Center today issued the first La Niña advisory under its new El Niño Southern Oscillation (ENSO) Alert System. Forecasters expect La Niña to influence weather patterns across the United States during the remainder of the winter and into the early spring.
Defined as cooler than normal sea surface temperatures in the central and eastern equatorial Pacific Ocean, La Niña impacts the weather globally. La Niña’s opposite is El Niño, or warmer than normal ocean temperatures. These changes in ocean temperatures alter the tropical wind and rainfall patterns with far reaching implications.
“The typical weather patterns associated with La Niña and El Niño affect many industries including agriculture, transportation, energy, shipping and construction,” said Michael S. Halpert, deputy director of the Climate Prediction Center. “The ENSO Alert System will succinctly inform industry, government agencies, academia and the public about the onset and status of La Niña and El Niño. This system will also help decision makers plan for the potential effects presented by these conditions.”
La Niña conditions have been present since late December, but it is too early to say exactly how strong the event will be and precisely how long it will last. However, for the next few months La Niña is expected to bring milder and drier than average conditions to the southeastern and southwestern states. It is also expected to bring wetter-than-average conditions to the Ohio and Tennessee valleys, and cooler than average temperatures to the Pacific Northwest.
The new ENSO alert system includes La Niña and El Niño watches and advisories which the Climate Prediction Center will issue when specific conditions exist.
These watches and advisories are now part of the ENSO Diagnostic Discussion, which is issued by the Climate Prediction Center on the Thursday falling between the 5th and 11th of every month. It is available online.NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.