The Atlantic Ocean is currently hurricane fuel.
Thanks to, among other factors, unusually warm sea surface temperatures, the National Oceanic and Atmospheric Administration (NOAA) now expects “an extremely active” Atlantic hurricane season, bumped up from the agency’s earlier prediction of “above normal” activity. In an announcement Thursday, NOAA said this storm prediction is “one of the most active seasonal forecasts that NOAA has produced in its 22-year history of hurricane outlooks.”
Already, the 2020 season has broken numerous records for the number of storms formed by this time of year. Now, the most active time of year is just around the corner, as most hurricanes form from about mid-August through late October.
Critically, more storms amp the odds of hurricanes striking land.
“In general, more active hurricane seasons have more landing hurricanes,” Philip Klotzbach, a hurricane researcher at Colorado State University, told Mashable in late April.
Colorado State’s updated storm outlook is similar to NOAA’s, but expects a little bit more activity. The university predicts 12 hurricanes and five major hurricanes (111 mph winds or higher), whereas NOAA expects between seven and 11 hurricanes, three to six of which could be major storms.
“This year, we expect more, stronger, and longer-lived storms than average, and our predicted ACE [Accumulated Cyclone Energy] range extends well above NOAA’s threshold for an extremely active season,” NOAA’s lead seasonal hurricane forecaster, Gerry Bell, said in a statement. ACE is the measure of a season’s total storm activity.
The big contributors to the extremely active season are:
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Warmer than usual ocean temperatures. “Ocean temperatures in the Atlantic are running much warmer than normal,” Brian Tang, an atmospheric scientist at the University of Albany, told Mashable in July. Warmer oceans fuel tropical storms as more water naturally evaporates into the air, . Overall, global oceans are absorbing nearly unfathomable amounts of heat as they soak up over 90 percent of the warmth created by human-caused climate change. (The ocean’s surface has warmed by , or 1 degree Celsius, since 1900.)
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What’s more, the Atlantic Ocean has also naturally been in a warmer phase since around 1995, something called the Atlantic Multi-Decadal Oscillation. This added warmth creates more ideal conditions for hurricanes to form.
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Hurricane scientists don’t expect strong east-driving winds blowing through the Caribbean this year. These winds pummel hurricanes (called “wind shear”). “It shears or tears apart storms,” Klotzbach told Mashable.
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A strong West African monsoon season is likely this year. Most powerful Atlantic hurricanes are seeded by unstable air and thunderstorms traveling west from Africa. More clouds and storm activity in West Africa are linked to favorable conditions for hurricanes.
A number of potent hurricane ingredients, then, have combined in 2020. Importantly, when thunderstorms do start journeying over the part of the Atlantic where most hurricanes form (called the Atlantic Main Development Region), they’ll get a boost from well-above average ocean temperatures. This area is about 1 degree Fahrenheit warmer than usual — which is a big change for the oceans.
“That extra degree makes it more likely the thunderstorms will survive going across the Atlantic,” Chris Slocum, a research meteorologist at the NOAA Center for Satellite Applications and Research, told Mashable in July.
In Earth’s warmer future over the coming decades and beyond, hurricane researchers don’t expect more hurricanes overall. However, they expect hurricanes , meaning higher wind speeds and more damaging and dangerous storms.
“We think there will be an uptick in the most intense storms,” said the University of Albany’s Tang.
