El Nino should last through March US weather svc.

NEW YORK, Jan 12 (Reuters) The current El Nino weather anomaly that can create atmospheric havoc around the world should continue into the spring, extending unseasonably warm North American temperatures through March, the US National Weather Service predicted.

The El Nino phenomenon, which warms sea surface temperatures in the Pacific Ocean and can disrupt weather patterns across the Western Hemisphere to the west coast of Africa, can cause flooding as well as drought but is said to have had a role in 2006's mild hurricane season.

Because of developments occurring now in the equatorial Pacific, the National Weather Service's Climate Prediction Center in Maryland said yesterday that El Nino-related effects over North America, including "warmer-than-average temperatures over western and central Canada, and the northern United States," were seen from January to March.

While the update said warmer ocean temperature anomalies were near their peak and should decrease from February through May, other factors were making that forecast risky.

The weather service also predicted "wetter-than-average conditions over portions of the US Gulf Coast and Florida, and drier-than-average conditions in the Ohio Valley and in portions of the Pacific Northwest" for the same period.

It said it had observed four increasingly bigger waves over the last nine months, with the most recent reaching the west coast of South America during the last half of December 2006.

That resulted in warmer subsurface and surface waters along the coasts of Ecuador and northern Peru, the CPC said.

CURRENT WEATHER SWELL FOGS OUTLOOK Temperatures have been decreasing, and without further wave activity ocean heat patterns may return to near average in a few months, the service said.

But forecasters warn that there is considerable uncertainty with this outlook, given a swell of precipitation now entering the western tropical Pacific.

The center said it will provide weekly updates on this latest condition that could trigger a more persistent pattern of cloudiness and precipitation in the next few weeks over the unusually warm waters of the central equatorial Pacific.

If that occurs, equatorial winds in the region will likely weaken and lead to warmer ocean temperatures.

Global effects the center sees through March include drier-than-average conditions over Malaysia, Indonesia, parts of Australia, northern South America and southeastern Africa.

The forecast also calls for wetter-than-average conditions over central South America, including Uruguay, northeastern Argentina, southeastern Paraguay, southern Brazil and possibly along the coasts of Ecuador and northern Peru.

This year's El Nino provided a respite to the US Gulf Coast and Central American countries slammed during 2005's record-setting hurricane season. It has also been cited for the unusually warm weather seen this winter in the Northern Hemisphere.

El Nino means "little boy" in Spanish. The pattern was named after the Christ child when it was first noticed by Latin American anchovy fishermen in the 19th century because it tends to peak around Christmas time.

REUTERS PDM DS1150