Hurricanes and climate change: Expert meteorologists discuss possible link

Our Changing Climate

SAVANNAH, Ga. (WSAV) — Residents of coastal Georgia and South Carolina are no strangers to impacts from tropical storms and hurricanes.

However, if the storms that head this way in coming years become much stronger than residents in the area are accustomed to, it could lead to potentially devastating future impacts in the Coastal Empire and Lowcountry, research suggests.

Recent research from the Intergovernmental Panel on Climate Change (IPCC) has found a link between global warming and hurricane activity

Studies have found it’s likely that rainfall from tropical cyclones will increase in the future. 

While that alone may be cause for concern for some, what’s potentially more alarming is that the intensity of those tropical cyclones might also increase, not just in the Atlantic Ocean, but also where tropical cyclones develop across the globe.

We are going to have more flooding in addition to raising the risk of more structural damage along the coastline when a hurricane does come through.”

SEAN SUBLETTE, CLIMATE CENTRAL METEOROLOGIST

Hurricane Dorian is a recent example of a storm that not only got more intense, but also did so in a very short period of time.

“What we’ve seen in the last couple of years is very warm water, little wind shear and storms that develop very rapidly,” said Storm Team 3 Meteorologist Kyle Dennis. 

Rapid intensification is what happens when a storm’s maximum winds increase by 35 mph or greater within 24 hours.

With Dorian, Dennis said, the storm first intensified to a Category 4 with winds up to 150 mph. 

“Then, there was a second rapid intensification to 185 mph, and we’ve seen a record number of storms undergoing those kinds of cycles,” Dennis said. “To see two rapid intensifications in that short a window is definitely something unusual, that’s not something that happens every year.”

One of the dangers with rapid intensification is that even if a storm’s track is well-forecast, an area that’s expecting landfall from a Category 2 may all of a sudden have to brace for a Category 4 that it’s not prepared for after the storm has ramped up within 24 hours, according to Dennis.

Warmer waters in the Atlantic may also be a cause of these more intense storms, according to Sean Sublette, a meteorologist for Climate Central.

“The number of storms isn’t necessarily going up,” Sublette told News 3. “The fact that the water on average is warmer, and that’s the main fuel for the hurricanes, allows them to get stronger.”

And there are a few very initial studies suggesting that they can get stronger faster. 

“For our money, I would say that warming waters can make stronger storms more likely, and a lot of our computer simulations and mathematical models will say the same thing, that as we go forward in the decades to come, that these very strong Category 4 and 5 storms will be more common,” Sublette said.

What this could mean for coastal areas along the East Coast, including Georgia and South Carolina, is more storm surge flooding, Sublette added.

We are going to have more flooding in addition to raising the risk of more structural damage along the coastline when a hurricane does come through,” he said.

Another trend where research is currently still trying to determine if a link to climate change exists is with slow-moving storms, which are very unusual, according to Dennis. 

“You look at Harvey that moved through Texas, which was a major hurricane, and one of the most severe impacts was that it just sat there for so long and dumped massive amounts of rain,” Dennis said. “When Matthew was coming up the coast here, it was a very slow mover, and Dorian stalled for more than 36 hours as a Category 5 in the Bahamas.”

“Meteorologically, if you were to have less of a temperature difference between the Arctic region and the equator, that would lead to less of a pressure difference in that area, and that means weaker steering flow, so that’s one possibility,” Dennis said.

He noted that from the mid-1990s to present day, there have been far more above-normal and even hyperactive Atlantic hurricane seasons when compared to the previous period from 1970 to 1994.

“[During that period], we were in a cooler phase, so naturally, we would get fewer active years with hurricanes,” Dennis said. “After that, we’ve been in a warm phase, but this has been a very extended warm phase, and this warm phase has been even warmer than ones in the past, and I think that’s also a contributing factor.”

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