John Wheeler, Published March 12 2014
Weather talk: NASA suspects El Nino brewing in Pacific OceanNASA issued an El Nino watch last week, indicating a growing confidence that an El Nino is brewing in the Pacific Ocean. El Nino brings a weakening trade wind pattern across the Pacific, which flips the temperature pattern. The western tropical Pacific grows drier (drought in Australia), while the eastern Pacific gets wet (rain in Chili). It also causes an overall rise in global temperature.
Effects are usually greatest from December through March. During the 1980s and 1990s, it often brought heavy rain to southern California and mild, open winters to the northern Plains. But since the big El Nino of 1998-99, the center of El Nino shifted west, and these relationships became weaker. The shift may be due to the development of the cold phase of the Pacific decadal oscillation, a more subtle Pacific circulation pattern.
More on El Nino tomorrow in this space.
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