La Niña seen to start earlier
The La Niña climate phenomenon may develop sooner, in the next few months, but forecasters expect it to be weak.
According to the United States National Oceanic and Atmospheric Administration (NOAA), most dynamical models of climate prediction suggest a La Niña onset as soon as the start northern hemisphere summer.
The NOAA was referring to a climate model that use super computers to solve mathematical equations that govern the motion of the atmosphere.
In its latest monthly update, the American agency said forecaster consensus was leaning toward this than many other models using statistics, which point to La Niña occurring in the autumn, no earlier than September.
“Overall, La Niña is favored to develop during the Northern Hemisphere summer 2016, with about a 75-percent chance of La Niña during the fall and winter 2016-2017,” the NOAA said.
“At this time, the forecasters are leaning toward a weak or borderline moderate La Niña if an event were to form,” it added.
The NOAA agreed with Australia’s Bureau of Meteorology (BoM) in the observation that the El Niño dissipated during the past four weeks.
Both agencies cite the return to normal of climate indicators on the surface and below the tropical region of the Pacific Ocean as well as the atmosphere above this.
“For the first time in 2016, atmospheric anomalies over the tropical Pacific Ocean were also consistent with neutral conditions,” the NOAA said.
A neutral condition refers to a scenario when there is neither El Niño which brings excessively dry conditions to the Philippines nor La Niña which has opposite effects.
Last week, the BoM placed the likelihood that La Niña will develop later this year at 50 percent.
“International climate models indicate the tropical Pacific Ocean will continue to cool, with six of eight models suggesting La Niña is likely to form during the austral winter (June-August),” the BoM said.
Subscribe to INQUIRER PLUS to get access to The Philippine Daily Inquirer & other 70+ titles, share up to 5 gadgets, listen to the news, download as early as 4am & share articles on social media. Call 896 6000.