What will El Nino Mean for US Weather?

El Niño is expected to be a dominant climate factor that will influence the December through February winter weather in the United States, according to the 2009 Winter Outlook released today 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 – a division of the National Weather Service. “Warmer ocean water in the equatorial Pacific shifts the patterns of tropical rainfall that in turn change the strength and position of the jetstream and storms over the Pacific Ocean and the U.S.”
 
“Other climate factors are also likely to play a role in the winter weather at times across the country,” added Halpert. “Some of these factors, such as the North Atlantic Oscillation are difficult to predict more than one to two weeks in advance. The NAO adds uncertainty to the forecast in the Northeast and Mid-Atlantic portions of the country.”

What does it mean for the Kansas & Missouri?
 
Here are the highlights according to NOAA. Warmer than average temperatures are favored across much of the western and central U.S, including Kansas & Missouri. This si especially true for the north-central states from Montana to Wisconsin. Though temperatures may average warmer than usual, periodic outbreaks of cold air are still possible. This seasonal outlook does not predict where and when snowstorms may hit or total seasonal snowfall accumulations. Snow forecasts are dependent upon winter storms, which are generally not predictable more than several days in advance.