El Niño in the central and eastern equatorial Pacific Ocean is expected to be a dominant climate factor that will influence the December through February winter weather in the U.S., according to the 2009 Winter Outlook released by NOAA’s Climate Prediction Center. “We expect El Niño to strengthen and persist through the winter months, providing clues as to what the weather will be like during the period,” says Mike Halpert, deputy director of the Climate Prediction Center. “Warmer ocean water in the equatorial Pacific shifts the patterns of tropical rainfall that in turn change the strength and position of the jet stream and storms over the Pacific Ocean and the U.S.” (More)