01:56 - Source: CNN
What exactly is El Niño?
(CNN) —  

El Niño can have major implications for weather patterns across the globe. On Thursday morning, NOAA announced that El Niño is here and issued an El Niño Advisory.

“El Niño conditions across the equatorial Pacific have come together, and we can now announce its arrival,” said Mike Halpert, deputy director, NOAA’s Climate Prediction Center, and ENSO forecaster.

NOAA gives a 55% chance of El Niño conditions persisting through the spring.


Sea surface temperatures in January -- orange-red colors are above normal.
NOAA
Sea surface temperatures in January -- orange-red colors are above normal.

“While sea surface temperatures are above average, current observations and climate models indicate that this El Niño will be weak, meaning we do not expect significant global impacts through the remainder of winter and into the spring,” Halpert said.

However, NOAA’s Climate Prediction Center said there is still a chance “the impacts often associated with El Niño may occur in some locations during the next few months.”

What is an El Niño?

During El Niño years, more rain falls in the Southwestern and Southeastern United States, while the North experiences much drier and warmer weather.

NOAA also said the current rainfall in California is not due to an El Niño, although that kind of weather is a typical symptom. But NOAA said another weather pattern, the Madden Julian Oscillation, is more likely responsible for the enhanced rainfall along the West Coast.

Forecasters say even a small El Nino can magnify weather events.

Recent studies show that climate change could be making the impacts from El Niños, even weaker ones like this one is supposed to be, worse,” said CNN meteorologist Brandon Miller.

“Spring is a time of year when ENSO (El Niño/Southern Oscillation, the entire El Niño and La Niña system) is often transitioning, making it especially difficult to predict what comes next,” NOAA said in its ENSO blog.

Predicting what comes next is exactly what hurricane forecasters are trying to do now for the upcoming Atlantic season.

Hurricane forecaster Philip Klotzbach of Colorado State University said there is a big question mark as to whether El Niño will affect this Atlantic hurricane season.

“Right now, NOAA is giving about a 40% chance of El Niño for August through October, the peak of the Atlantic hurricane season,” he said. “If the El Niño were to persist, it would likely reduce Atlantic hurricane activity, due to increased vertical wind shear, especially in the Caribbean.”