Where Have All the Atlantic Hurricanes Gone? El Niño Is Keeping the Season Quiet

This hurricane season in the Atlantic Ocean has been unusually calm — and scientists say a weather pattern called El Niño is the main reason why. Not a single hurricane has formed in the Atlantic so far this year, even though this time of year is normally the busiest part of the season. Only five weak tropical storms have appeared, and forecasters say no hurricanes are likely to develop for at least another week. On Saturday, this year set a record for the longest stretch without a hurricane since scientists began tracking storms by satellite.

Scientists measure overall hurricane activity by looking at how many storms form, how strong they are, and how long they last. Right now, storm activity in the Atlantic is only 7% of normal for this time of year — a record low since 1950, according to Colorado State University hurricane expert Phil Klotzbach. That means the Atlantic is nearly silent when it comes to big storms. Experts say this is a remarkable and historic stretch of quiet weather.

Even so, weather experts warn people not to let their guard down. It only takes one powerful storm to cause serious damage, even in a slow season. Scientists point to 1992 as an example — that year started very quietly but then produced Hurricane Andrew, one of the most destructive storms in U.S. history. So while things look calm now, the danger is never completely gone.

El Niño is a natural weather event in which parts of the Pacific Ocean near the equator get warmer than usual. This warming changes weather patterns all around the world. In the Atlantic, El Niño creates conditions that make it very hard for hurricanes to form or grow. Five different weather experts explained this to The Associated Press.

Professor Kristen Corbosiero from the University at Albany described it as a 'triple whammy' hitting any storm that tries to form. First, strong winds at different heights blow in opposite directions, tearing storms apart — this is called wind shear. Second, very dry air moves in and starves the storm of the moisture it needs to grow. Third, winds push air downward, which stops storms from building up. Together, these three forces are destroying every storm before it can get going.

The strongest El Niño effect in the Atlantic right now is that record-breaking wind shear. In the area between Africa and the Caribbean — where the strongest Atlantic hurricanes usually form — the wind shear is about 45 miles per hour stronger than what a tropical storm can survive. 'Their heads are cut off before they even have a chance,' said University of Miami hurricane expert Brian McNoldy. Corbosiero called this an unheard-of level of wind shear.

There is one area where conditions are a little different: the Gulf of Mexico. Wind shear has not been as strong there, and storms in the Gulf tend to pick up strength later in the season. Scientists say there could still be some strong storms hitting the Gulf region before hurricane season ends. People living along the Gulf Coast should stay alert and keep watching weather forecasts.

Along with wind shear and dry air, African dust is also drifting across the Atlantic and making it even harder for storms to grow. High pressure in the Atlantic is pushing air downward, adding another obstacle for any storm trying to form. All of these are classic signs of El Niño at work, experts say. Even though the ocean water is very warm — the world's oceans have been at record-high temperatures for 100 days — El Niño is powerful enough to overcome the heat.

Massachusetts Institute of Technology professor Kerry Emanuel explained why warm water alone isn't enough to fuel a hurricane. What really matters, he said, is the difference in temperature between the ocean water and the air above it. Because El Niño heated up the atmosphere so quickly, the air is now almost as warm as the water, which means less energy flows from the ocean into a storm. The ocean water is lagging a few months behind the atmosphere in feeling El Niño's full effects.

While the Atlantic is sleeping, the Pacific is having a very different experience. El Niño tends to make the Pacific more active, and this year, storms there are nearly double the normal amount. There have already been 16 named storms in the eastern Pacific and 20 in the central Pacific, compared to just five small tropical storms in the entire Atlantic. Hawaii has even been hit twice this year, and scientists say the season there has been far busier than usual.