BREAKING: El Niño has begun! NOAA's Climate Prediction Center made the declaration Thursday morning.
El Niño starts with westerly winds across the equatorial Pacific. Those winds blow warm surface waters eastward, creating a warm pool in the eastern tropical Pacific.
That heats the air above, causing rising, and inducing a chain reaction process that shuffles key weather patterns in the global atmosphere.
This could be one of the strongest, if not the strongest, El Niño since recordkeeping began in 1950.
In the United States, we’re expecting a stronger, straighter west-to-east wintertime jet stream over the South. That will mean wetter conditions and more severe weather along the Gulf Coast. In Florida, that will mean markedly more rainfall and tornadoes!
Drier and warmer conditions are more likely this winter over the central and northern Lower 48.
Drought is likely in southern Africa, Australia, India, the Indochina Peninsula and Oceania. Southeast Asia, meanwhile, could see above-average rainfall and more flooding.
Regarding hurricanes, good news for the Atlantic... not-so-good for the Pacific.
In the central and eastern Pacific, rising air will support more hurricanes than average. But what goes up must come down. Subsidence, or sinking air over the Atlantic, is expected to suppress tropical activity, reducing the number of tropical storms and hurricanes that develop.
El Niño is the opposite of La Niña. The two make up ENSO, or the El Niño Southern Oscillation. El Niño is the warm phase; La Niña is the cool phase. They switch every 2-7 years give or take.
El Niño doesn't start suddenly; it emerges gradually. Scientists look at sea surface temperature anomalies in the Niño 3.4 region, or an imaginary box in the Pacific. One the three-month running mean is 0.5ºC (0.9ºF) above average for at least five consecutive months, El Niño has begun.
