Atlantic hurricane season is off to a quiet start, and El Niño is likely the reason. A natural climate pattern, El Niño is marked by warmer-than-average water temperatures in the equatorial Pacific and corresponding shifts in upper atmosphere weather patterns. This year’s El Niño was officially declared in June and could become a record-breaking Super El Niño later this year.
Impact on Hurricane Season
The potential fingerprints of El Niño are taking the form of storm-killing wind shear, which has been particularly strong over the Caribbean Sea and the western Atlantic Ocean. Wind shear describes the changes in wind direction or speed between different levels of the atmosphere and can tear apart tropical systems or prevent them from forming.
According to Michael Lowry, a Miami-based hurricane expert, the number one calling card of El Niño is that wind shear. Lowry noted that wind shear over the Caribbean had its second-highest start to July since satellite records began in 1979. This significant wind shear is one of the stronger indicators of future seasonal hurricane activity.
While El Niño might not be the sole cause of the intense wind shear, it is the prime suspect, and the evidence is piling up. The current wind shear behavior is matching up closely with what’s expected from El Niño, according to Matthew Rosencrans, a meteorologist with NOAA.
Global Implications
Signs of El Niño are starting to show up in other global-scale atmospheric wind and weather patterns, including the Walker Circulation. This circulation is part of the process that notches up wind shear over the Atlantic during El Niño years, helping suppress the storms that could grow into a tropical system.
Other experts have come to similar cautious conclusions. Levi Silvers, a research scientist and co-author of Colorado State University’s hurricane season forecasts, stated that all the pieces are fitting together in a way that makes sense and is consistent with the science that we already understand.
The strong statistical relationship between stronger wind shear in the Caribbean and western tropical Atlantic in July and a less active peak hurricane season suggests that this year’s hurricane season might be quieter than normal. However, threats can still develop closer to home, in the Gulf or along the southeastern coast.
Original reporting: KTVZ (Central Oregon) — read the source article.
