As the Pacific warms, there is a growing chance of neutral El Niño-Southern Oscillation (ENSO) conditions this spring, according to the latest update from NOAA Thursday morning, with a better than 50% chance of El Niño returning this autumn, including the peak of hurricane season.
We are nearing the peak of the current La Niña, solidly in the moderate category as far as La Niñas go. This area of colder water is circled in red on the map below.
La Niña occurs when the ocean's surface temperatures in the central and east-central equatorial Pacific reach a specific cooler-than-average temperature. El Niño is the warming of the same area of the Pacific and has a different set of weather effects around the planet.
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Neutral conditions are the state between El Niño and La Niña, meaning the water in the Pacific is neither warmer nor cooler than average. This condition will be reached after near-average temperatures are sustained for a multi-month period, and will be indicated by the disappearance of blue colors on the map below in the circled area.
Here's what this forecast means for the next few months:
Impacts
Spring impacts:Years that have shifted from moderately (and relatively) chilly in the Pacific to average have featured some predictable temperature tweaks stateside from March to April.
Cooler-than-average temperatures from the Northern Rockies to the interior Northeast.
Reliably warmer than average temperatures in the Southeast and in the Southwest.
By May and June, the signal becomes much more mixed using these analogs, but that's not surprising as the jet stream, and its influence over the Lower 48, typically weakens. One of the meteorological features that ENSO has its hands in is the jet stream. Warming conditions in the Pacific (i.e. a slide toward neutral conditions) could also muddy any connections with weather in the U.S.
Summer impacts?El Niño and La Niña usually have their biggest impacts on the weather in winter, when they've been in place for several months. But if El Niño can develop fast enough, it could at least subtly affect both temperatures and rainfall in the U.S. this summer.
El Niño summers tend to be cooler in the East and Rockies and wetter in the Southeast.
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From a global perspective, the defining warmth of an El Niño will give this summer a push toward the top of the warmest years on record.
(Further beef up your forecast with our detailed, hour-by-hour breakdown for the next 8 days – only available on ourPremium Pro experience.)
Quieter hurricane season ahead?In El Niño hurricane seasons, stronger shearing winds and sinking air often occur over at least the Caribbean Sea and some adjacent parts of the Atlantic Basin. This tends to limit the number and intensity of storms and hurricanes, especially if the El Niño is stronger.
El Niño isn't the only factor that can shape how a hurricane season goes. Bursts of dry air and sinking air or a lack of tropical waves are all other factors that can change how a season goes.
Forecast caveat you should know about:What lies beyond the springtime months is often highly uncertain.
That's because of what's known as aspring predictability barrier– a time of year when models struggle with accurate predictions.
Spring is a time when the ocean is more likely to be closer to average in the temperature department due to the shift out of the polarized summer and winter seasons in their respective hemispheres.
Winds across the equator are also often weaker during the spring because there's less temperature contrast in either hemisphere.
These factors make the signals that climatologists use to make forecasts more fuzzy, leading to a drop off in the accuracy of the forecasts.
Jonathan Belleshas been a digital meteorologist forweather.comfor 9 years and also assists in the production of videos for The Weather Channel en español. His favorite weather is tropical weather, but also enjoys covering high-impact weather and news stories and winter storms. He's a two-time graduate of Florida State University and a proud graduate of St. Petersburg College.
