Updated

Federal weather forecasters say the La Nina weather phenomenon that contributed to the southwestern U.S. drought is winding down.

The National Weather Service's Climate Prediction Center says La Nina is showing signs that it will be over by summer. Center deputy director Mike Halpert said that's too late for the U.S. southwest because the rainy season will be over by that time. The effects of La Nina, a cooling of the central Pacific, are generally weaker in summer.

But it is good news for the Atlantic hurricane belt. More tropical storms form there during La Ninas.

Halpert said La Nina generally causes more weather damage to the U.S. than its flip side, the better known El Nino.

This La Nina was known as "double-dip" La Nina because there was a La Nina in the winter of 2010-11, then the waters in the Pacific warmed to a neutral state and then cooled again to another La Nina for 2011-2012.

Forecasters don't know what conditions will follow this La Nina. Usually a multi-year La Nina is not followed by a neutral event, Halpert said. It either goes to El Nino or comes back as another La Nina, he said.