Strong odds of El Nino weather event's return by end of year, bringing more warming

The U.N. weather agency says there's a strong chance an El Nino weather event will reappear before the end of the year.

The El Nino, a flow of unusually warm surface waters from the Pacific Ocean toward and along the western coast of South America, shakes up climate patterns worldwide and usually raises global temperatures.

An update Thursday from the World Meteorological Organization puts the odds of El Nino at 60 percent between June and August, rising to 75-88 percent between October and December.

WMO Secretary-General Michel Jarraud says El Nino leads to "extreme events and has a pronounced warming effect" on top of man-made global warming.

The outlook is for peak strength during the last quarter of the year and into the few months of 2015 before dissipating.