We actually don’t know how ‘bad’ hurricane season could be yet

The metrics may have changed, but the message is still the same: Hurricanes can be deadly, destructive — yet, very difficult to understand. And they happen every year irrespective of a seasonal forecast, a pandemic or even climate change.

An active season is likely again this year in the Atlantic basin, according to NOAA and all other reputable forecast agencies. Most projections are even higher than the new 30-year averages that were increased earlier this spring.

Now that the headline of an active season has passed, let’s remember that it only takes one storm to devastate a community or shift one’s paradigm on preparedness. The misaligned perception of risk a seasonal forecast presents is just one of the many challenges public safety communicators face prior to hurricane season.

Whether a season is deemed “bad” is often based on a recollection of a storm’s precise track, strength and motion. However, these parameters have been proven difficult to predict five days out, much less months in advance.

While track forecasts from the National Hurricane Center have improved steadily since 1970, intensity forecasts have only recently begun to improve. Climate change has also complicated matters. For example, warmer oceans are a likely contributor to more instances of rapid intensification. This can make alerting the public to higher winds, more rain and a deeper storm surge even more difficult when it happens prior to landfall, such as with Hurricanes Harvey in 2017 and Michael in 2018.

Furthermore, the correlation between the total number of hurricanes that form and those that affect land is also weak (or unpredictable). For example, an average of 6.7 hurricanes per year have formed in the Atlantic basin since 1980. However, only 25 percent of those (or 1.7 per year) have made landfall or produced hurricane conditions over land in the Continental United States. In addition, there have been five seasons with above-normal hurricane activity and no U.S. impact. Yet, major hurricanes have also come ashore during relatively quiet years (compared to normal) five times in the past 40 years.

With all the attention seasonal forecasts have been getting, I did a little research and found that the correlation to U.S. landfalls is weak. So it’s not inaccurate for me to say active hurricane seasons aren’t always ‘bad’, and quieter years can still be devastating. pic.twitter.com/WdcQ1QXxBT

— Jeff Huffman (@HuffmanHeadsUp) June 4, 2021

Since hurricanes have been the deadliest and costliest billion-dollar natural disaster in the United States over the past four decades, one might believe climate change and population growth along hurricane prone coastlines would exacerbate those numbers. But this too has become difficult or premature to assess, much less predict.

The economic impact of hurricanes has certainly been on the rise. Four of the top $5 billion disaster years since 1980 have occurred in succession since 2016, and the CPI-adjusted disaster costs over the last 10 years (from 2011 to 2020) have also been historically large. However, a notable decrease in direct deaths attributed to hurricanes during this period has also been observed.

One of the reasons being theorized for the reduction in deaths is a change in storm surge messaging the National Hurricane Center began in 2017. Surge has been the leading cause of hurricane-related fatalities for several decades, and since it’s not always collocated with the wind, new watches and warnings were created as a separate “call to action.” Since 2017, there have been 14 hurricanes making landfall, including six major hurricanes. During this time, there have only been seven storm surge fatalities reported out of 235 total storm-related deaths.

One could also argue luck has also played a role in this reduction, which was highlighted on the last page of the Hurricane Irma report from 2017. A subtle 30-mile shift in the track of the Category 3 hurricane resulted in 150,000 fewer people finding themselves surrounded by a deadly storm surge. 

Consequently, a concern residents near Lake Charles, Louisiana wouldn’t be as lucky in the path of major Hurricane Laura in 2020 led to the unprecedented publication of the word “unsurvivable.” The National Hurricane Center forecasters used it to describe the potential impacts from their surge forecast of 15 to 20 feet (which was actually 18 feet), and this is believed to have aided in a nearly 100 percent evacuation compliance rate and no known deaths from Laura’s surge.

While progress may be occurring on mitigating direct deaths from hurricanes (such as those that are surge related), the number of indirect deaths has been found to be almost as large. These causes of death come from cardiac arrest, electrocution, vehicle accidents or the misuse of generators and chain saws. A similar emphasis by risk communicators on post-storm hazards might also reduce these trends in the future.

In conclusion, the way in which risk is communicated immediately before, during and after a hurricane is far more effective than the seasonal forecasts that get reported each spring. It’s also plausible that climate change and population growth is playing a role in how extreme the impact could be from any given hurricane. But whether those impacts are related to a larger seasonal change in the frequency or strength of storms is still unknown. 

What matters most is that those who live, work or play in harm’s way understand their risk — and most importantly recognize that the hazards are unique to each storm and their situation. 

Jeff Huffman leads the Florida Public Radio Emergency Network and South Carolina Emergency Information Network, a collaboration of public television and radio stations that delivers public safety information related to hurricanes and other natural disasters to audiences in both states. Huffman is a meteorologist and has more than 17 years of experience as a weather and risk communicator.