LOS ANGELES — A weather-altering El Nino is increasingly likely to develop in the Pacific Ocean later this year, according to a U.S. government forecast issued Thursday.
National Oceanic and Atmospheric Administration meteorologists now believe an El Nino has a 66 percent chance of forming by this winter.
If the prediction materializes and the influential climate pattern sets in, it could bring wetter weather to California and the southern U.S., suppress the Atlantic hurricane season and compound global warming by boosting temperatures in 2015.
In Hawaii, El Nino tends to bring dry winters, according to NOAA. Drought is more likely during El Nino years, particularly between October and March.
El Nino, which correlates with warmer ocean temperature, can also cause increased storm activity and late season storms. La Nina, features cooler waters and historically has produced below normal activity seasons. Warmer waters fuel convection and storms.
Government forecasters say observations and computer models in recent weeks indicate that water below the surface in the eastern tropical Pacific Ocean is warming and showing increasing signs that an El Nino is afoot.
“The odds are increasing but still not 100 percent,” said Mike Halpert, acting director of NOAA’s Climate Prediction Center.
After inching slowly upward, the chances of an El Nino surpassed 50 percent last month, prompting NOAA to activate its alert system and issue an official El Nino watch.
A forecast by Australia’s Bureau of Meteorology on Tuesday predicted a 70 percent chance of an El Nino in the coming months.
The naturally occurring climate cycle occurs every two to seven years when weak trade winds allow warmer surface water to pile up along the west coast of South America, shifting storm activity and altering precipitation patterns around the globe.
The pattern has been in a lull for the last two years, with the eastern Pacific never warming enough to form an El Nino or cooling to generate a La Nina. The last El Nino, in 2009-10, was moderate and followed by the cool-water phase, La Nina.
In 2009, there were seven storms that passed through the Central Pacific Ocean basin, according to the Central Pacific Hurricane Center. The Central Pacific hurricane season runs June 1 to Nov. 30.
NOAA’s latest forecast gives a 30 percent likelihood of conditions remaining neutral by year’s end and a 4 percent probability of a La Nina.
West Hawaii Today digital content editor Chelsea Jensen contributed to this report.