UPDATE 1-El Nino seen developing in Sept-Oct -UN weather body


GENEVA, Sept 25 (Reuters) - An El Nino event, usually

associated with significant changes in rainfall, is likely to

develop this month and next in the Pacific, affecting global

climate patterns, the World Meteorological Organization (WMO)

said on Tuesday.

The phenomenon, characterised by unusually warm ocean

temperatures in the tropical Pacific, has been linked previously

to drier-than-normal conditions in Australia, Indonesia, the

Philippines, northeastern Brazil, southeastern Africa and parts

of Asia, the United Nations agency said.

"A weak El Nino may develop in September and October and

last until the northern hemisphere winter," the WMO said in a


El Nino is also associated with wetter-than-normal

conditions in Ecuador, northern Peru, southern Brazil to central

Argentina and parts of eastern Africa, it said.

El Nino winters tend to be mild over western Canada and

parts of the United States and wet over the southern United

States, it added.

La Nina, its opposite phenomenon which causes an abnormal

cooling of waters, ended in April.

The WMO update is based on many different climate forecast

models gathered from centres around the world.

"The majority of these climate forecast models say that

there is a 'moderately high likelihood' of an El Nino. Having

said that, it can't be ruled out that neutral conditions may

continue," WMO spokeswoman Clare Nullis told a news briefing.

The Geneva-based WMO promotes cooperation among its 189

member states and their national meteorological and hydrological

services and is the U.N. system's voice on weather, climate and