At the beginning of this Atlantic Hurricane Season in June, scientists projected a record active year, with dozens of named storms and several very strong hurricanes. It seemed as though those predictions would come to fruition early in the season with two landfalls: Beryl in Texas and Debby in Florida, bringing hurricane conditions, flooding, and damaged infrastructure. A long gap followed before Francine affected eastern Louisiana and Mississippi in mid-September. Aside from those storms, it seemed as though projections for an unusually active hurricane season might not come to fruition.
Still, scientists cautioned that it wouldn’t take much to end the hurricane dry spell and tip back into more active conditions. And this past week, that seems to have happened. Not only are there multiple areas of interest in the Atlantic basin as of this writing, a significant portion of the southern Appalachian mountains, not to mention the entire Gulf Coast of Florida, are cleaning up tonight after Hurricane Helene, a storm that will go down in infamy with storms like Harvey and Katrina. Flash flooding and storm surge flooding have washed away whole communities and badly damaged road networks, hampering search and rescue and relief efforts.
The question some are asking is whether Hurricane Helene was made worse by climate change. The Yale Climate Connections Blog has a great article about the science behind hurricanes and climate change. To summarize: Hurricane Helene is an example of the kind of hurricane that you would expect to see in a warming climate. It rapidly intensified as it approached the coast due to the very warm sea surface temperatures. Its peak intensity, which is also tied to sea surface temperatures, made the winds up to ten times more destructive than a storm with lower wind speeds. It drove an extremely large storm surge, made worse by sea level rise. And it produced prodigious amounts of precipitation, in part because the warm Gulf of Mexico promotes evaporation and a warmer atmosphere holds more water vapor, increasing precipitation rates.
There were other factors that contributed to Hurricane Helene, including its interaction with upper level winds and its rapid forward speed, which allowed it to maintain hurricane strength further inland than if it had been moving more slowly.
Even though we are only halfway through the alphabet, scientists point out that this has been an active season when it comes to US landfalls:
Colorado State Meteorologist Philip Klotzbach noted on X how unusual it is to have four landfalls in the US in a single season:
“#Helene is forecast to make landfall tomorrow as a major #hurricane in the Big Bend of Florida. It would be the 4th Gulf Coast hurricane landfall in 2024. Only 5 other years on record (since 1851) have had 4+ Gulf hurricane landfalls: 1886, 1909, 1985, 2005, 2020.”
Contrast 2024 (so far) with the 2005 Atlantic Hurricane Season. There were so many storms that season (thirty) that they ran out of alphabet-based names and began naming storms after Greek letters. Four of those storms were Category 5, the highest rating on the Saffir Simpson scale (storms can be rated Category 5 when they are still out at sea, even if they make landfall at a lower rating, like Katrina which made landfall as a Category 3 hurricane).
We don’t know yet how this hurricane season will play out in terms of the quantity of storms. But it has already been a record-breaking season in terms of the impact and intensity of the storms we have seen.
As a coastal state, Texas is vulnerable to hurricanes. We should pay attention to the way hurricanes are changing as the climate warms and plan accordingly for our coastal communities. Backup power systems, hazard-resistant building codes, incentives to relocate out of the areas at risk of storm surge flooding, all of these are options for ways to make the inevitable impact of a future hurricane more bearable.