Mild Winter Coming for Most of U.S.

Oct. 10, 2006 — -- If you live almost anywhere west of the Mississippi or north of the Ohio Valley, government forecasters say to expect a warm winter.

The Climate Prediction Center of the National Oceanic and Atmospheric Administration today released its outlook for December through February, and its MAP clearly shows a diagonal line across the country. The closer you are to the upper Midwest, the more likely you are to have a milder-than-normal winter.

How can the Climate Prediction Center predict the entire winter when accurately forecasting a few days in advance seems hard enough? Blame it all on El Niño.

An El Niño is a giant patch of warm, steamy water that periodically forms along the equator in the Pacific Ocean. While the causes are complex, the effects are clear for much of the planet.

Jet streams, passing over El Niño, change paths in predictable ways. Often the high-level jet streams that pass over the tropical Pacific steer northward.

"The strengthening El Niño event will influence the position and strength of the jet stream over the Pacific Ocean, which in turn will affect winter precipitation and temperature patterns across the country," according to a statement from NOAA. "This event is likely to result in fewer cold air outbreaks in the country than would be expected to occur in a typical non-El Niño winter."

And an El Niño can stay in place for months on end. So, prevailing conditions change. While it may be hard for your local forecaster to tell you whether it's going to rain this weekend, it's actually easier to forecast the overall climate conditions for large parts of Earth months in advance.

"In our lifetimes, these El Niño events are essentially the largest global disturbance of the world climate pattern that any of us will experience," said Bill Patzert, an oceanographer at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The climate forecast coincided with a projection from the Department of Energy, saying home-heating bills are likely to be slightly lower than they were last winter. If you use natural gas, you can expect to spend $119 less, on average, than you did last year -- though, if you heat with oil, you can expect the average bill to go up $91.