LONDON (Reuters) - The El Niño climate phenomenon, which has started in the tropical Pacific, could strengthen from September, Britain's Met Office said on Friday.
Observations from the tropical Pacific show that weak El Niño conditions have started for the first time in five years, the Met Office said.
"The current outlook suggests that at least a moderate El Nino is likely and there is a risk of a substantial event," it said in a statement.
"While it is still too early to determine with confidence how strong this El Niño might be forecast models from centers around the world, including the Met Office, suggest this El Nino could strengthen from September onwards," it added.
On Thursday, the U.S. National Weather Service's Climate Prediction Center said El Niño had a 90 percent likelihood of continuing through the summer.
El Niño is a warming of the Pacific Ocean as part of a complex cycle linking atmosphere and ocean. It sees a huge release of heat from the Pacific Ocean into the atmosphere, which can disrupt weather patterns around the world.
It can be linked with monsoons in Southeast Asia, droughts in southern Australia, the Philippines and Ecuador, blizzards in the United States, heatwaves in Brazil and extreme flooding in Mexico.
Even a strong El Niño should not be a dominant driver of British weather over the next few months, Met Office said.
"Looking further ahead, there are a number of factors that affect winter conditions in Britain. The increase in risk of a colder winter this year from the developing El Niño is currently considered small," it added.
Reporting by Nina Chestney; editing by Jason Neely