Signs of El Niño are already appearing in the Atlantic Ocean
Early Indicators of El Niño Emerge Across the Atlantic Basin
Signs of El Niño are already – The current Atlantic hurricane season has begun with remarkably little activity, prompting meteorologists to direct their attention toward El Niño as the primary cause. For those needing a reminder, this phenomenon represents a recurring climatic cycle characterized by elevated sea surface temperatures within the equatorial Pacific region. These warmer waters trigger significant alterations in the upper-level atmospheric circulation. Together, these elements exert influence over global weather systems for extended durations. Authorities formally recognized the onset of this event during the month of June. Furthermore, there is growing speculation that it may evolve into a historic Super El Niño before the calendar year concludes.
The Dominant Role of Wind Shear
Its potential fingerprints are taking the form of storm-killing wind shear, smudging up a hurricane season that’s produced one short-lived tropical storm to date. It’s the quietest start to the season since 2009. Wind shear describes the changes in wind direction or speed between different levels of the atmosphere. It can tear apart tropical systems or prevent them from forming in the first place — and it’s established a firm grip over the Caribbean Sea and the western Atlantic Ocean. June and July are typically the quietest months of the season, but this shear has been a major roadblock and could have implications for the peak months, too.
“The number one calling card of El Niño is that wind shear,” said Michael Lowry, a Miami-based hurricane expert with CNN affiliate WPLG-TV.
Wind shear over the Caribbean had its second-highest start to July since satellite records began in 1979, according to National Oceanic and Atmospheric Administration data parsed by Lowry. And having such significant wind shear over the Caribbean and the western Atlantic — which should be active areas for tropical development — is “one of the stronger indicators that we look to for future seasonal hurricane activity,” Lowry said. El Niño might not shoulder all the blame for the intense wind shear that’s been around at least since the season began on June 1, but it’s the prime suspect and the evidence is piling up.
Scientific Links and Atmospheric Patterns
The current wind shear behavior is matching up closely enough with what’s expected from El Niño that the two are likely related, according to Matthew Rosencrans, a meteorologist with NOAA. The in-depth studies needed to confirm this link won’t come until after hurricane season ends in November, he noted. The uncertainty lies in the chaotic, complex atmosphere: Global weather patterns that unfold over weeks — or months — and daily weather are all connected in a way that’s sometimes difficult to pick apart.
But signs of El Niño are starting to show up in other global-scale atmospheric wind and weather patterns, including the Walker Circulation, according to Lowry, which lends more credence to the idea that El Niño has its finger on the scales. The Walker Circulation is part of the process that notches up wind shear over the Atlantic during El Niño years. It’s a loop consisting of rising and sinking air, which encourage and hinder storm development, respectively. Air rises above the now warmer Pacific, then sinks down over parts of the western Atlantic basin, helping suppress the storms that could grow into a tropical system.
“I don’t think we can say exactly that (current wind shear) is for sure caused by the El Niño, but I think it’s very likely that it is,” said Levi Silvers, a research scientist and co-author of Colorado State University’s hurricane season forecasts.
Forecast Adjustments and Regional Threats
Other experts have come to similar cautious conclusions. “All the pieces are fitting together in a way that makes sense and a