Featured image: June 30, 2024 – Hurricane Beryl was pictured east of Barbados as a Category 3 storm from the International Space Station as it orbited 263 miles above the Atlantic Ocean. Via NASA.
On Friday, June 28, the National Hurricane Center began advisories on Tropical Depression Two, east of Barbados. Within 48 hours, it was Category 4 Hurricane Beryl. After another 24 hours, it was the earliest Category 5 hurricane on record.
Just before Beryl made landfall in Jamaica on Wednesday, July 3, we sat down with Dr. Marshall Shepherd, Georgia Athletic Association Distinguished Professor of Geography and Atmospheric Sciences at the University of Georgia and accomplished meteorologist, to learn more about Beryl– and what it indicates for the future of hurricanes.
Hurricanes belong to a class of storms called tropical cyclones. They derive energy from ocean heat content and favorable upper atmospheric conditions devoid of strong wind shear (change in speed or direction with altitude). Through complex energy transfer from the ocean to the atmosphere, changes in atmospheric pressure can affect winds. The categorization of a tropical storm or hurricane depends on how fast these winds are moving. Wind speeds of 39-74 miles per hour are considered a tropical storm. When winds exceed 74 mph, they are associated with hurricanes on a scale that increases all the way up to 157+ mph: a Cat. 5 hurricane.
“Hurricanes like warm water, they like high ocean heat content, and we certainly have plenty of that,” Shepherd explained. “It’s actually interesting that water temperatures are plenty warm enough, but we thought that some of the strong [wind] shear would start to weaken it, and we’ve seen a slight downtick… but it has not really taken its toll as much as some of us thought it would, because that water temperature is so strong, so high.”
Hurricanes generally begin as clusters of thunderstorms over very warm surface waters (above 80 degrees Fahrenheit/27 degrees Celsius), meaning they really only occur in tropical and subtropical regions. Once they move out of the tropics and surface water temperatures begin to drop, they typically weaken and dissipate.
“There’s this backdrop climate discussion that we have to have, not just climate change, but short-term climate variability, sub-seasonal variability,” Shepherd explained. “We’re currently entering a La Niña phase, that’s the cool phase of what we call the ENSO cycle, the El Niño Southern Oscillation. During the warm phase, El Niño, eastern Pacific waters are very warm. During the cold phase, they’re cooler than normal, and we call that La Niña. Those warm and cold phases affect our atmospheric patterns, and La Niña conditions tend to promote a more active Atlantic hurricane season because wind shear conditions are more favorable for development. Now you couple that with that extremely warm water that we talked about… it’s a recipe for a really active hurricane season.”
But we’ve had plenty of La Niña hurricane seasons before. Why are meteorologists so concerned about this one?
The weather interactions that cause hurricanes are dependent on warm water. Early in the season, water temperatures are slower to warm than air temperatures, so hurricane season generally kicks off with weaker storms, which increase in average intensity as waters warm throughout the late summer. Officially, Atlantic hurricane season begins on June 1, and usually peaks around September. But water temperatures are warming earlier in the year, with ocean waters reaching August-like conditions as early as May. This points to something meteorologists and climate scientists have been warning us about for years: climate change, including warming temperatures and sea level rise, is making storms worse.
“The 2024 hurricane season has been projected to be very active. We’re seeing that right before our eyes,” Shepherd warned. “The fact that we are, as you and I are talking about this, Hurricane Beryl is on our doorsteps and will impact Jamaica here shortly on July 3, now that’s bizarre. That’s just stunning people like me, because we typically don’t see Category 4 Category 5 major hurricanes before the Fourth of July.”
What does a changing hurricane season mean for coastal communities?
“Let’s come to the U.S. for a second, assuming Hurricane Beryl and others to follow likely will impact some part of the U.S. in the coming months,” Shepherd said. There are major population centers all across the Gulf Coast, Florida and up the U.S. East Coast, from Texas to the Carolinas, and many are significant centers of infrastructure, manufacturing and industrial activity.
“One of the things that many colleagues at N-EWN and within IRIS and the University of Georgia have been working on is thinking about things like compound disasters, compound flooding,” Shepherd explained. “My colleague, Dr. Matt Bilskie, thinks about what happens when hurricanes make landfall. You’ve got the storm surge, you’ve got freshwater flooding from rain, and some riverine flooding that comes later. How does that impact communities, society, industry and so forth?”
Another major research topic within coastal scientists and meteorologists is the concept of pre- and post-disaster risk, and the use of nature-based solutions to help mitigate risks. “For example,” Shepherd noted, “we know that wetlands are natural buffers for storms as they make landfall.” These types of solutions can help make communities more resilient to the trend of larger, more frequent hurricanes. With Beryl forming so quickly this early in the year, it’s unlikely to be an easy hurricane season.
“At the end of the day, much of the southern part of the United States has infrastructure vulnerabilities and societal or human vulnerabilities, because we know that many of the most vulnerable populations in the United States are the communities of color, elderly, poverty, that are found in southern states,” Shepherd concluded. “When we have hurricanes or extreme weather events, compounded with other things– like the COVID pandemic or power outages and so forth– these lead to cascading effects on communities.”
Over the Fourth of July holiday, Beryl hammered Jamaica and the Cayman Islands, and progressed over the weekend across the Yucatán Peninsula and into the Gulf of Mexico. Early on Monday, July 8, Beryl made landfall in Texas as a Category 1 hurricane and is projected to send heavy rainfall up across the U.S. Midwest and East Coast throughout the week.
Follow updates on Hurricane Beryl here. Check out Dr. Shepherd’s podcast with The Weather Channel, Weather Geeks, here.
The projected path of Hurricane Beryl as of Friday, July 5. Early on Monday, July 8, Beryl made landfall near Matagorda, TX. Via National Hurricane Center, NOAA.
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