US Got “Lucky” with 2021 Hurricane Season—3rd Most Active in Recorded History

November 30, 2021 | 3:41 pm
Composite image of tropical storm tracks in 2021. AveryTheComrade/Wikimedia Commons
Astrid Caldas
Senior Climate Scientist

Update: Corrects second paragraph under “The numbers.” Eight storms made landfall in the US in 2021. An earlier version of this blog post stated that 13 storms made landfall.

The end of the official Atlantic hurricane season is upon us. While we may still see tropical storms forming, historic data tells us the worst of it should be over. How did the 2021 season fare? In a nutshell, what we saw was not really what was happening in terms of storm activity: basically, we in the US got “lucky.”

Throughout the season, I kept an anxious eye on the National Hurricane Center page, checking it with dread, watching 3, 4, 5 systems churning in the North Atlantic, some storms forming abruptly. I hoped against hope that they would dissipate or veer away from land, and some indeed dissipated or spun out over the Atlantic. Yes, there was terrible devastation, especially to those in the path of Ida, but that potentially pales compared to what could have been with all those storms if they had tracked on a different path.

The numbers

Many people may not be aware that, as of this writing, 2021 was the third most active season since recordkeeping began in 1851, with 21 named storms that included 7 hurricanes, 4 of which were considered major (two Category 3 and two Category 4). The 2020 and 2015 seasons were first and second busiest, respectively. That was pretty much on the mark for the season outlook update from the National Oceanic and Atmospheric Administration (NOAA), which projected 15-21 named storms, with 7-10 becoming hurricanes, of which 3-5 could become major hurricanes. Colorado State University considered its own forecast (which comes out before NOAA’s) a success.

Eight storms made landfall in the US this year. It was the seventh consecutive season to have its first named storm (Ana) form before the official season start on June 1, the third time the list of 21 names was used up, and the fourth costliest season, with over $70 billion in damages and 161 fatalities.

One may be surprised to hear all that, since news of storms and hurricanes pretty much petered out after hurricanes Larry and Nicholas in September, well before the letter W (Wanda, the last named storm of the season) was reached. But let’s take a look at what happened in more detail.

The Gulf

Scenes of destruction were a lot less prevalent in the news than in 2020 (thankfully), with one devastating exception: hurricane Ida, which underwent rapid intensification (much the same as 10 storms in 2020) and made landfall in Port Fourchon, LA, as a Category 4 hurricane with 150mph winds. The destruction in its wake, not only in Louisiana but across the US as it made its way north, was staggering. Tornados and heavy rain triggered by Ida’s system occurred from Louisiana, Mississippi, and Alabama through the mid-Atlantic all the way to New York, a rare occurrence that far north. Ida ended its run as the fourth deadliest storm in history, with 91 deaths reported as of September 9. 

Source: https://stacks.cdc.gov/view/cdc/110013

Ida was not the only storm in the Gulf of Mexico: seven of the 21 named storms this year tracked somewhere in the Gulf. In 2020, several storms (some back-to-back) also hit the Gulf: Louisiana was hit by 5 landfalling storms (Cristobal, Marco, Laura, Delta and Zeta); Eta and Iota hit Nicaragua within weeks of each other. Some are even calling Florida and Louisiana “a magnet for storms.”

One cannot help but wonder about the future, and a recent study has found that Florida and Louisiana may be potentially more prone to receiving sequential storms.

Under a high-emissions scenario—meaning if we keep pumping unabated heat-trapping emissions in the atmosphere —the study found that most coastal regions of the US had an increasing potential for sequential landfalling tropical cyclones (tropical storms and hurricanes) since 1979, but that Florida and Louisiana are more likely than most regions to experience such a phenomenon. The study also found that the chance of the interval between storms being of 10 days or fewer will be doubled in this century. The implications for preparations and recovery are immense and obvious —when there is not much time between storms, the impacts can compound to an even more dangerous level. We saw what happened when Hurricane Laura hit the Louisiana Lake Charles area in August 2020 as a Category 4, then Hurricane Delta hit the same general area only six weeks later. The potential for that gap between storms to be fewer than two weeks is concerning, to say the least.

The East Coast

The East Coast of the US was largely spared bad direct hits this season, with many storms meandering in the Atlantic, getting nowhere near the US. Instead, most of the impacts came from remnants of storms that hit the Gulf and moved north—Ida being the biggest one.

While of course this is good news this year, a recent study has highlighted the likelihood of worse hurricane outcomes for the East Coast—with not only more storms impacting the area, but also with those storms causing more damage because of a projected pattern of slowing down and/or stalling once they reach land. That will allow for more rain and potential worsening impacts from flooding, similar to what happened with Hurricane Harvey and several other storms in recent years—patterns also highlighted in previous studies (see here for example). The findings also have important implications for how local, state and federal governments, as well as homeowners and businesses plan to prepare for worsening climate change impacts in the coming years, especially given the large population along the East Coast.

Awareness of climate change and its impacts on weather is increasing

A recent poll from the Yale Program on Climate Change Communication has shown that, for the first time, a majority of the US population (52 percent) have “personally experienced the effects of global warming”, and those who “think global warming is happening outnumber those who think it is not by a ratio of more than 6 to 1 (76 percent versus 12 percent).” Seven in ten think global warming is affecting weather in the United States.

Various studies have evaluated how exposure to extreme weather events and natural disasters affect people’s perceptions and actions about climate change and its impacts. A study from 2019 found that the level of impact of a disaster (such as flood) in a community or neighborhood affects beliefs in climate change and perceptions of future risk. Another study from 2020 found that a high-impact event is necessary for communities to engage in and/or support policies or actions to reign in heat-trapping emissions and adapt to unavoidable climate impacts.

Some have suggested that catastrophes are short-lived in people’s minds and do not lead to long-term action, and using a crisis approach to address long-term needs can actually lead to inaction. And an analysis of studies evaluating the efficacy of fear or threats on actions found that fear only works when accompanied by ways to reduce the threat—in other words, explain the threat clearly but say what can be done to deal with it.

Climate change is real, it is happening, it is bad… and there’s something we can do about it!

At the Union of Concerned Scientists, we strive to bring reliable climate science to the general public, policymakers, and impacted communities. And we always also bring recommendations on how risks and impacts could be minimized, how those unavoidable impacts can be dealt with, and what the global community and governments can do to avoid the worst of climate change. We always make sure to highlight that the most important action to be taken is the swift reduction of warming emissions, and a quick shift to renewable energy, in order to keep warming well below 2°C as per the goal of the Paris Agreement and the will of the global community.

The 2021 hurricane season, busy as it was and devastating as it was—especially to those in the path of Ida—is what it looks like to get “lucky” in our warmed world. Hurricane risk with climate change is about playing with loaded dice. I mentioned some of the ways science shows the dice are loaded here and in previous posts (here and here.) The three busiest seasons in history happening just in the past seven years points to the dice being loaded, and the science increasingly supports that. And yet despite that, we came out of this season much less scathed than we could have— yes, the devastation of Ida was terrible, but with the loaded dice it could have been much worse, both in terms of that storm itself and of other storms that could have reached the US.

We must act now to reduce emissions and avoid the worst of climate change and its impacts, keeping communities safe, listening to the science, and safeguarding critical systems across the globe. Time is running out to make the changes that can alter the outcome of our trajectory. It is critical to make the most of the “calm before the storm” to prepare and reduce risks. We won’t always be this “lucky.”