La Nina may form in Pacific by May as El Nino disappears

NEW YORK (Reuters) - The La Nina weather anomaly may form in the equatorial Pacific in the next two to three months, possibly increasing the risks for more hurricanes later this year in the Atlantic.

"A transition to La Nina conditions is possible during the next two to three months," the U.S. Climate Prediction Center of the National Oceanic Atmospheric Administration (NOAA) said in its monthly update on Thursday.

It also said the El Nino weather pattern, whose wind shear ripped apart and reduced the amount of hurricanes in the Atlantic Ocean in 2006, has disappeared.

Typically, El Nino causes rampant flooding in Peru and Ecuador while causing searing drought in Australia, Indonesia and the Philippines among other countries.

La Nina usually has the opposite effect, and U.S. government forecasters have warned it may cause a higher-than-normal number of hurricanes.

For instance, with El Nino running at full bore last year, only nine named storms formed in the Atlantic. That was much lower than the record 28 storms in 2005 that included monster storms like Hurricanes Katrina, Rita and Wilma which ravaged the U.S. Gulf Coast and caused billions of dollars worth of damage.

The prediction center said warm sea surface temperatures that accompanied the last El Nino fell rapidly last December and January.

"These trends in surface and subsurface ocean temperatures indicate that the warm (El Nino) episode has ended and that conditions are becoming favorable for La Nina to develop," it said.

Some of the computer forecast models "indicate a rapid transition to La Nina conditions during March-May 2007," the center added.