Hurricane Helene struck the southeastern United States today, causing devastating flooding and at least one death. 40 people in 4 states. The number of deaths is likely to increase further.
The storm hit the coast Thursday evening as a Category 4 hurricane, with maximum sustained winds of 140 mph. It also caused flooding storm surge. As I write this Friday afternoon, it has been downgraded to a tropical storm but still poses a catastrophic risk.
“Historic, catastrophic and life-threatening flash and urban flooding, including numerous severe landslides, will continue in parts of the southern Appalachians through this evening.” National Hurricane Center.
Including Helen, the United States has now experienced a record eight disasters. Category 4 or Category 5 Atlantic hurricane landfall Over the past 8 years (2017-2024). “This is the same number of Cat 4 and 5 landings that have occurred in the last 57 years.” write Meteorologist Jeff Masters.
Hurricanes take advantage of ocean heat and convert it into wind energy. According to Masters, “Hotter oceans could make hurricanes more powerful, assuming other factors exist that power hurricanes, including low wind shear and a moist atmosphere.”
As it turns out, this time there’s record-breaking heat for Helene to devour, which is of course linked to climate change. But before we dig deeper into the possible climate connections, check out this: We compile remote sensing images of the storm to highlight some of its important features.
GOES-16 Satellite Image
The remarkable evolution of Hurricane Helen over just two and a half days can be seen in this animation of GOES-16 satellite imagery. From tropical disturbances in the Caribbean to devastating Category 4 hurricanes along Florida’s Gulf Coastline. (Credit: CSU/CIRA and NOAA).
As seen by the GOES-16 satellite, Helene is evolving into a Category 4 storm whose eyewall is broken by lightning. (Credit: CSU/CIRA and NOAA).
Hurricane Helen made landfall in Florida’s Big Bend region on September 26, 2024, as a Category 4 storm with maximum sustained winds of 140 mph, as seen in this infrared photo captured by the GOES-16 satellite. (Credit: CSU/CIRA and NOAA).
A 12-hour time-lapse GOES-16 satellite image shows Hurricane Helen making landfall and barreling inland, causing catastrophic rainfall and catastrophic flooding. (Credit: CSU/CIRA and NOAA).
Back to Climate Connections…
Even before anything actually happened, hurricane experts were worried. Brian McNoldy, University of Miami put it September 17, “Nothing to look at yet, but a widespread low pressure system could form east of Honduras Friday-Saturday and track as it consolidates northward from there.”
McNoldy and others expressed concern about record-breaking hurricane fuel in the western Caribbean, namely sky-high ocean warmth. “All of this means that if something were to form in the western Caribbean any time soon, the ocean would provide endless high-octane fuel for it.”
Marine heat mass (meaning the heat energy stored in the ocean) has reached an all-time high in the Caribbean. (Credit: Brian McNoldy, University of Miami)
As we now know, the disturbance that exploded into Hurricane Helen did indeed form at breakneck speed.
But on September 23, Helen had not yet turned into a true storm. Nonetheless, McNoldy was growing increasingly concerned and predicted that it was very likely that the disturbance would escalate rapidly once it entered the Gulf of Mexico.
“Not only do ocean surface temperatures along its path reach 30-31C, but the warm water flows deep and creates extremely high ocean heat content…an endless source of fuel,” he wrote. “When it comes to hurricanes, warm oceans are a big part, but not all.”
As the storm moved from the Caribbean Sea to the Gulf of Mexico, it appears to have eaten a large tongue-shaped patch of particularly warm water. You can see it here.
September 23, 2024 A tongue-shaped piece of unusually warm water extending into the Gulf of Mexico is visible here. The visualization was created using data obtained from satellites and instruments on the surface. (Credit: NASA Worldview.)
The warm tongue extended from the Caribbean Sea northward toward the Florida Panhandle and into the Gulf of Mexico. It was a sign that the Loop Current, which helps send water from the Caribbean Sea to the Gulf of Mexico, had unleashed a warm eddy that was “lingering uncomfortably close to the U.S. coast.” According to NASA.
As McNoldy had predicted, Helene strengthened very quickly, raced quickly towards land, and then charged deep inland.
And as we have seen, they dumped huge amounts of water, causing catastrophic floods. There may be a climate connection here too. That’s because warming increases water evaporation into the air, so warmer temperatures can hold more water vapor. As a result, rainfall increased. Moreover, as water vapor condenses into liquid, it releases heat, which can help sustain the entire chain of events.
We don’t yet know how much climate change has affected Helene. So in the coming weeks, scientists will “Attribution” research It could potentially shed more light on the link between Helene and climate change. Stay tuned.
In the meantime, I highly recommend Jeff Masters’ in-depth look at this topic for more details.Four reasons climate change likely made Hurricane Helen worse“
