Climate Phase Forecast
Updated: August 15th, 2011
La Niña watch issued for the upcoming fall/winter.
It is more likely than not that La Niña will redevelop in the next 1-3 months.
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Current East Pacific SST Analysis |
Current East Pacific SST Anomaly Analysis |
Last summer witnessed an abrupt change from El Niño to La Niña in the tropical Pacific Ocean. El Niño refers to a periodic (every 2-7 years) warming of the tropical Pacific Ocean along the equator from the coast of South America to the central Pacific, where La Niña is much the opposite phase where the same area cools down several degrees Celsius below normal. Both phases have dramatic impacts on the climate patterns of the Southeast, especially in the winter months. Last year’s La Niña began as one of the strongest on record in August and September and maintained its strength through spring of 2011.
The summer season saw a return to near-normal sea surface temperatures in the tropical Pacific (Neutral Phase), but the atmosphere continued to show signs of La Niña’s influence in strong easterly low-level winds, lack of cloudiness or rain in the central Pacific, and negative SOI. In addition, La Niña’s are often multi-year events, especially when the first year is a strong episode. For this reason we have been warning about the possibility of a return to La Niña this fall and winter. Now, several coupled ocean-atmospheric models, including NOAA’s CFS, are now indicating changes in the system and are predicting the return of La Niña. Based on the historical tendency for strong episodes to last more than one year and now the agreement of some dynamic models, we are predicting a greater than 50% chance of La Niña redeveloping this fall and winter.
La Niña is known to bring drier than normal weather and climate patterns to Florida and coastal areas of the Southeast and also Texas and the desert Southwest. Last year’s strong event was the primary trigger for the unprecedented drought in Texas and New Mexico and very dry conditions here in the Southeast. A second year of La Niña could bring similar rainfall patterns and bring continued or even worsening drought to these hard-hit areas.
For more information on how La Niña affects the climate of the Southeast, please reference our climate outlook and the Climate Risk Tool available on this website.
The SECC tracks the phase of the Pacific Ocean using the MEI index. For more information and current MEI 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.