La Nina To Build, Dictate U.S. Winter Weather: NOAA

Christopher Doering PlanetArk 22 Oct 10;

A strengthening La Nina weather phenomenon will grip the United States this winter, bringing warmer, drier weather across the South and cooler, moist conditions in the far northern and western parts of the country, government forecasters said on Thursday.

The National Oceanic and Atmospheric Administration said a "moderate to strong" La Nina looks to become one of the strongest on record throughout the winter -- making it the most dominant factor influencing weather across the country.

"I do believe that really the story of this winter is likely to be the dry conditions across the South," said Mike Halpert, deputy director of NOAA's Climate Prediction Center.

"It's something we've seen very consistently with many of these La Ninas in the past," he told reporters, adding the dry weather could set the stage for drought or near drought-like conditions early next year.

The weather anomaly could be troublesome for the South, where the potential of drought conditions developing would threaten U.S. crops as farmers sow winter wheat and get fields ready for 2011 spring plantings of grains and cotton.

"There would be a concern for winter wheat in the South and Southeast, if the dry weather remains into the spring growing season. We could lose bushels, if that happens," said Shawn McCambridge, an analyst for Prudential Bache Commodities.

The winter outlook, covering December through February, was uncertain for the Northeast, the world's largest heating oil market, and the Midwest, where residents depend mostly on natural gas for home heating.

NOAA said the Central, Northeast and Mid-Atlantic regions each have an equal chance of temperatures and precipitation being above, near or below normal this winter, but the agency cautioned its forecast could change.

U.S. consumers already are expected to see home heating bills rise 3 percent to $986 this winter due to higher fuel prices and colder weather in the Northeast, the U.S. Energy Information Administration said last week. EIA also expects higher costs for heating oil, natural gas, electricity and propane.

NOAA said that, while increased energy demand is forecast this winter in the Northeast, it reflects a return to a more normal seasonal temperature after the region was hit by warmer weather, despite several large snowfalls, last year.

La Nina, which means "little girl" in Spanish, is associated with cooler-than-normal water temperatures in the Equatorial Pacific, unlike its sibling El Nino, which has the opposite effect.

In the hydro-electric dependent U.S. Pacific Northwest, weather is expected to be colder and wetter than average this winter. La Nina often brings lower-than-average temperatures and increased mountain snow to the Pacific Northwest and western Montana during the winter months.

Weather forecasters on Thursday predicted colder and wetter than average conditions in the Northern Plains, which could lead to more storms and flooding. In the citrus-producing state of Florida, drier than average conditions, which could lead to an above normal wildfire season, are expected.

(Additional reporting by Sam Nelson; Editing by David Gregorio and Walter Bagley)