El Niño forming quickly and could be a ‘significant’ event, NOAA finds

The odds are very high that an El Niño event will form this summer, hastening climate change and altering global weather patterns.

The National Oceanic and Atmospheric Administration (NOAA) now says an El Nino event could begin within two months – and there is a greater than 90 percent chance it will last into winter in the northern hemisphere.

“Keep your eyes peeled on the tropics, and don’t blink,” Nathaniel Johnson, a meteorologist at NOAA’s Geophysical Fluid Dynamics Laboratory, wrote in a NOAA blog post. “Conditions are evolving quickly!”

It is possible this could be the first year in which the global average surface temperatures bump up against the Paris Agreement’s more stringent climate change target of 1.5°C (2.7°F) above preindustrial levels, Zeke Hausfather, climate research lead at payments company Stripe, told Axios.

Some parameters to keep an eye on

During El Niño, the trade winds weaken, which leads to increased sea levels and warmer-than-average ocean temperatures along the western coasts of the American continents.

Experts are also concerned that recent high sea surface temperatures will make the upcoming El Niño worse. The average global sea surface temperature in early April was the highest in recorded history. 

Besides the increased sea surface temperature, there is also the presence of unusually warm waters beneath the surface, which are sloshing from the Western Pacific eastward; and shifting trade winds.

The most recent sea level data from the U.S.-European satellite Sentinel-6 Michael Freilich also indicate early signs of a developing El Niño across the equatorial Pacific Ocean.

Interestingly, the data shows Kelvin waves, which are roughly 2 to 4 inches (5 to 10 centimeters) high at the ocean surface and hundreds of miles wide, moving from west to east along the equator toward the west coast of South America.

The beginning of spring often witnesses the onset of these Kelvin waves, and their appearance is a widely recognized early warning of an upcoming El Niño.

Satellites like Sentinel-6 Michael Freilich can detect Kelvin waves with a radar altimeter, which uses microwave signals to measure the height of the ocean’s surface. When an altimeter passes over areas that are warmer than others, the data will show higher sea levels.