Supercharged hurricanes? Let's take a closer look
Another record hurricane season has residents asking how climate change might be fueling more destructive tropical storms. Here's a look at what may be going on.
By
Mary Gilbert, AccuWeather meteorologist
Updated Sep 25, 2021 11:10 PM EST
Hotter oceans, global warming and vertical wind shear are all factors impacting the number and intensity of hurricanes we could see in the future.
Residents who reside along America's coastlines have certainly felt the brunt of an active and destructive hurricane season, and experts say climate change is a contributing factor to just how supercharged hurricane seasons have become in recent years.
The 2021 Atlantic hurricane season is going toe-to-toe with the 2020 season's record-breaking pace. With 19 named tropical systems in the basin this year--seven of those hurricanes--meteorologists are currently expected to dip into a supplemental list of storm names for the second consecutive year. A normal Atlantic hurricane season consists of 14 named storms, seven hurricanes and three major hurricanes.
"Last year to this year during hurricane season, we had four bad [storms] that have torn houses up--it's happening a lot faster," Pamela Winkworth, a resident of Lake Jackson, Texas, told AccuWeather's Bill Wadell.
Climate scientists say warmer waters in the Gulf of Mexico and the Atlantic Ocean are fueling more robust tropical storms and hurricanes.
"More than 90 percent of the warming on Earth between 1971 and 2010 occurred in the ocean, and eventually much of that heat will have to be released into the atmosphere," said AccuWeather Senior Meteorologist Brett Anderson.
Water temperatures in the tropical Atlantic during hurricane season have will mean greater impacts on people. (Climate Central)
Water temperatures in the tropical Atlantic during hurricane season have risen about 1.85 degrees Fahrenheit over the past 100 years, Climate Central reported in 2020. When combined with the warming atmosphere, this means storms have a greater potential for strengthening — sometimes rapidly — leading to greater impacts on people.
"You also have more moisture that’s just in the atmosphere in general, because of a warmer planet and so that means when we get precipitation... from a hurricane there’s more rain to fall and to flood an area," Ilissa Ocko, a climate scientist with the Environmental Defense Fund, told Wadell during a recent interview for AccuWeather Prime.
Scientists say warmer oceans are contributing to sea-level rise due to multiple factors including thermal expansion and the melting of ice sheets and coastal glaciers. Any rise in sea levels can spell trouble for coastal communities dealing with powerful storms.
Hurricane Fran off the coast of Florida in 1996 (NASA)
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"A lot of land ice is melting from mountain glaciers and also from the ice sheets, and so that’s pouring extra water into the ocean, [and a] storm pushes all that water onshore, which is known as a storm surge," Ocko continued.
According to the National Weather Service, storm surge is often the greatest threat to life and property from a tropical system. Storm surge often leads to rapid rises in water levels and can flood large areas in just minutes, potentially catching residents in the vicinity off guard.
In addition to storm surge, the overall forward motion of a tropical system is crucial to just how dangerous the storm can become.
"The forward speed of storms, especially when they move inland, is slower now than let's say it was, maybe 30, 40 years ago," AccuWeather Hurricane Expert Dan Kottlowski explained.
According to Kottlowski, there are questions about a major factor that could potentially limit the frequency of hurricanes in the future, but not necessarily the strength of the systems.
A slower forward motion of a tropical entity means that a tropical storm or hurricane will be able to spend more time over warm water, which can fuel additional development and strengthening. A slower forward motion also means storms aren't moving and are instead able to dump hours, or perhaps a full day, of torrential rainfall over coastal communities.
"[Studies have shown] there would be more vertical wind shear showing up across the Atlantic basin. In those studies, they determined that there would actually be fewer storms 20, 30, 40, 50 years from now, but [the storms] were more powerful," Kottlowski explained.
Atlantic tropical storm and hurricane tracks as of Sept. 20, 2021.
AccuWeather forecasters emphasize that the focus should not be on the overall number of storms but on what these storms can actually do once they form. How quickly storms can intensify, the ultimate threshold of strength they reach and their speed at landfall are all much more important factors when working to protect lives and property.
In November 2020, researchers with Japan’s Okinawa Institute of Science and Technology published a study that showed hurricanes are staying stronger after making landfall. The study, which was published in the journal Nature, found “a significant long-term shift towards slower decay,” which allows storms to maintain a higher intensity over land for a longer time period.
On Aug. 29, Hurricane Ida made landfall shortly before 12 p.m. local time in southeastern Louisiana as a Category 4 storm with maximum sustained winds around 150 mph. Ida maintained Category 4 intensity through much of that day until it dropped to Category 3 strength around 6 p.m. local time and Category 1 strength by 11 p.m the same day.
Experts are currently debating the need to make the hurricane season longer. Earlier this year, the National Hurricane Center (NHC) said it would begin issuing tropical weather outlooks on May 15, about two weeks ahead of the official June 1 start date. The NHC is considering starting the season on May 15 in future years.
Prior to the current season, Dennis Feltgen, a spokesman for the NHC, told AccuWeather in an email that named storms have formed prior to the official start of the hurricane season in about half of the past 10-15 years, including each of the past six years. That trend continued in 2021 with the formation of Subtropical Storm Ana on May 22.
"Many of the May systems are short-lived, hybrid (subtropical) systems that are now being identified because of better monitoring and policy changes that now name subtropical storms," Feltgen added.
Reporting by AccuWeather's Bill Wadell
For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
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News / Hurricane
Supercharged hurricanes? Let's take a closer look
Another record hurricane season has residents asking how climate change might be fueling more destructive tropical storms. Here's a look at what may be going on.
By Mary Gilbert, AccuWeather meteorologist
Updated Sep 25, 2021 11:10 PM EST
Hotter oceans, global warming and vertical wind shear are all factors impacting the number and intensity of hurricanes we could see in the future.
Residents who reside along America's coastlines have certainly felt the brunt of an active and destructive hurricane season, and experts say climate change is a contributing factor to just how supercharged hurricane seasons have become in recent years.
The 2021 Atlantic hurricane season is going toe-to-toe with the 2020 season's record-breaking pace. With 19 named tropical systems in the basin this year--seven of those hurricanes--meteorologists are currently expected to dip into a supplemental list of storm names for the second consecutive year. A normal Atlantic hurricane season consists of 14 named storms, seven hurricanes and three major hurricanes.
"Last year to this year during hurricane season, we had four bad [storms] that have torn houses up--it's happening a lot faster," Pamela Winkworth, a resident of Lake Jackson, Texas, told AccuWeather's Bill Wadell.
Climate scientists say warmer waters in the Gulf of Mexico and the Atlantic Ocean are fueling more robust tropical storms and hurricanes.
"More than 90 percent of the warming on Earth between 1971 and 2010 occurred in the ocean, and eventually much of that heat will have to be released into the atmosphere," said AccuWeather Senior Meteorologist Brett Anderson.
Water temperatures in the tropical Atlantic during hurricane season have will mean greater impacts on people. (Climate Central)
Water temperatures in the tropical Atlantic during hurricane season have risen about 1.85 degrees Fahrenheit over the past 100 years, Climate Central reported in 2020. When combined with the warming atmosphere, this means storms have a greater potential for strengthening — sometimes rapidly — leading to greater impacts on people.
"You also have more moisture that’s just in the atmosphere in general, because of a warmer planet and so that means when we get precipitation... from a hurricane there’s more rain to fall and to flood an area," Ilissa Ocko, a climate scientist with the Environmental Defense Fund, told Wadell during a recent interview for AccuWeather Prime.
Scientists say warmer oceans are contributing to sea-level rise due to multiple factors including thermal expansion and the melting of ice sheets and coastal glaciers. Any rise in sea levels can spell trouble for coastal communities dealing with powerful storms.
Hurricane Fran off the coast of Florida in 1996 (NASA)
CLICK HERE FOR THE FREE ACCUWEATHER APP
"A lot of land ice is melting from mountain glaciers and also from the ice sheets, and so that’s pouring extra water into the ocean, [and a] storm pushes all that water onshore, which is known as a storm surge," Ocko continued.
According to the National Weather Service, storm surge is often the greatest threat to life and property from a tropical system. Storm surge often leads to rapid rises in water levels and can flood large areas in just minutes, potentially catching residents in the vicinity off guard.
In addition to storm surge, the overall forward motion of a tropical system is crucial to just how dangerous the storm can become.
"The forward speed of storms, especially when they move inland, is slower now than let's say it was, maybe 30, 40 years ago," AccuWeather Hurricane Expert Dan Kottlowski explained.
According to Kottlowski, there are questions about a major factor that could potentially limit the frequency of hurricanes in the future, but not necessarily the strength of the systems.
A slower forward motion of a tropical entity means that a tropical storm or hurricane will be able to spend more time over warm water, which can fuel additional development and strengthening. A slower forward motion also means storms aren't moving and are instead able to dump hours, or perhaps a full day, of torrential rainfall over coastal communities.
"[Studies have shown] there would be more vertical wind shear showing up across the Atlantic basin. In those studies, they determined that there would actually be fewer storms 20, 30, 40, 50 years from now, but [the storms] were more powerful," Kottlowski explained.
Atlantic tropical storm and hurricane tracks as of Sept. 20, 2021.
AccuWeather forecasters emphasize that the focus should not be on the overall number of storms but on what these storms can actually do once they form. How quickly storms can intensify, the ultimate threshold of strength they reach and their speed at landfall are all much more important factors when working to protect lives and property.
In November 2020, researchers with Japan’s Okinawa Institute of Science and Technology published a study that showed hurricanes are staying stronger after making landfall. The study, which was published in the journal Nature, found “a significant long-term shift towards slower decay,” which allows storms to maintain a higher intensity over land for a longer time period.
On Aug. 29, Hurricane Ida made landfall shortly before 12 p.m. local time in southeastern Louisiana as a Category 4 storm with maximum sustained winds around 150 mph. Ida maintained Category 4 intensity through much of that day until it dropped to Category 3 strength around 6 p.m. local time and Category 1 strength by 11 p.m the same day.
Experts are currently debating the need to make the hurricane season longer. Earlier this year, the National Hurricane Center (NHC) said it would begin issuing tropical weather outlooks on May 15, about two weeks ahead of the official June 1 start date. The NHC is considering starting the season on May 15 in future years.
Prior to the current season, Dennis Feltgen, a spokesman for the NHC, told AccuWeather in an email that named storms have formed prior to the official start of the hurricane season in about half of the past 10-15 years, including each of the past six years. That trend continued in 2021 with the formation of Subtropical Storm Ana on May 22.
"Many of the May systems are short-lived, hybrid (subtropical) systems that are now being identified because of better monitoring and policy changes that now name subtropical storms," Feltgen added.
Reporting by AccuWeather's Bill Wadell
Related:
For the latest weather news check back on AccuWeather.com. Watch AccuWeather Network on DIRECTV, DIRECTVstream, Frontier, Spectrum, fuboTV, Philo, and Verizon Fios. AccuWeatherNOW is streaming on Roku and XUMO.
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