Climate Phase Forecast
Date Updated:May 21, 2008
La Niña continues to weaken, but may still impact our climate for the next 1-2 months.
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Current East Pacific SST Analysis |
Current East Pacific SST Anomaly Analysis |
Colder than normal surface temperatures spread over most of the tropical Pacific Ocean in the fall of 2007 consistent with a phenomenon known as La Niña. La Niña can be thought of as the opposite of the better known “El Niño“, where the Pacific Ocean along the equator from the South American coast to the western Pacific turns several degrees C warmer than normal. The colder than normal temperatures continued to spread and intensify during the past fall and winter seasons and the La Niña event grew in magnitude until it was considered a moderate to strong event. The colder ocean temperatures peaked in February and have been returning to normal ever since.
Right now, portions of the western and central Pacific Ocean (near the equator) are still cool enough to be considered a weak La Niña. Areas further east and near the coast of South America have sea surface temperatures that are close to normal. The atmosphere above the tropical Pacific is also still displaying La Niña characteristics, mainly stronger than normal trade winds and reduced cloudiness over the central Pacific. Atmospheric conditions related to La Niña often persist for a couple months after sea surface temperatures return to neutral conditions, so expect La Niña to impact the climate of North America through June or July.
What will happen in the Pacific Ocean later in 2008 is much less certain. Some El Niño/La Niña prediction models show a continued decay of La Niña well into the summer, while others predict a return of La Niña in the fall of 2008. Multi-year La Niña’s have happened in the past, most recently in 1998-2000. Keep in mind that these long range predictions are quite uncertain, especially at this time of year when the dynamics of the Pacific are not well understood. La Niña favors warm and dry winter conditions in the Southeast, but mixed patterns in April and May. A resurgence of La Niña later in the fall would favor a more active hurricane season. Even a switch to El Niño is possible later this fall, though not as likely as Neutral conditions or a return to La Niña. For more information on climate impacts in the Southeast, see the latest climate outlook.
The SECC tracks the temperatures of the Pacific Ocean using the JMA index. For more information and current JMA values, see the following link:
Other El Niño/La Niña Forecasts
Below are links to El Niño/La Niña forecasts from other centers in the U.S. and worldwide. Caution: the SECC may not agree with their forecasts and/or classification criteria.