5 things to know about the 2024 atlantic hurricane season forecast

The 2024 Atlantic hurricane season could be a busy one.

The U.S. National Oceanic and Atmospheric Administration’s (NOAA) annual forecast, released in late May, predicts an 85% chance of an above-normal season, with just a 5% chance of a below-normal season.

That presents an opportunity for FM’s clients to plan, prepare and invest in a more resilient future. In this article, FM chief science officer Dr. Louis Gritzo and Research Director for Climate Risk & Resilience Dr. Angelika Werner lay out five key factors our clients should know about the 2024 Atlantic hurricane season forecast.

Forecasters agree: The ingredients are in place for an active Atlantic hurricane season

NOAA forecasts between 17 to 25 named storms in the 2024 season – the most in the forecast’s history. That’s in line with a slew of other forecasts from academic, public and private entities, Werner says.

“All forecasts predict consistently above normal activity,” says Werner, who recently attended the international Symposium on Hurricane Risk and Climate Change.

Two major factors come into play here: unprecedentedly warm water temperatures in the North Atlantic Ocean and a likely shift from last year’s El Niño toward neutral or weak La Niña-type conditions, Werner says.

Going deeper: Warmer water temperatures provide more fuel to the convective systems, but are also associated with weaker trade winds and lower than normal sea level pressure in the region, all factors supporting the formation, duration and intensification of storms, Werner says. Additionally, an ending of the long-lasting El Niño conditions will reduce vertical windshear, which has previously disrupted some storm formations; without as much of it, storms have an easier time forming and lasting. NOAA’s latest forecast predicts only a minor chance of 1-2% of an El Niño lasting over the peak season of July-September.

Of course, it’s impossible to say exactly how many storms will happen this year or where or if they will make landfall. But what we can say is that the ingredients are in place for an active hurricane season, Gritzo and Werner say.

Climate change and hurricanes

In a recent article in Forbes, Gritzo wrote that there’s little evidence that climate change is causing more landfalling Atlantic hurricanes. Werner adds: The scientific community is still debating whether the number of hurricanes in the Atlantic is likely to increase in the future.

But a changing climate is creating the conditions for bigger – and potentially more dangerous – storms.

Warmer water: Storms can form more easily and intensify more quickly in warmer ocean water, Werner says. When storms intensify more quickly, people and communities have less warning and less time to prepare. Last year Hurricane Otis developed from a Category 1 to a Category 5 hurricane in just 24 hours before it hit Acapulco, one of a string of storms that strengthened rapidly in the North Atlantic and Eastern Pacific over the past couple of years.

Warmer air: Warmer air can hold more moisture – a 7% increase for every degree Celsius. That drives the potential for more rainfall during a storm, Werner says.

Finally, sea level rise will make storm surges even more of a threat to coastal communities.

Research continues into these influences, and the science is still unsettled around exactly how climate change is affecting hurricanes.

But "there’s a lot more potential for bigger storms in a changing climate than there was in the past,” Gritzo says.

The connection between property loss and tropical cyclones – timing, location and development are key

Whether a tropical cyclone blows out to sea or cuts a devastating path of destruction comes down to synoptic patterns that are difficult to forecast longer term. A more active hurricane season doesn’t necessarily mean more insured losses, says Werner.

In the United States, though, we have been developing more infrastructure and growing in hurricane-prone areas. In his Forbes piece, Gritzo writes that nine out of the top 10 hurricanes by cost occurred in this century – not because of more storms but because of more property in their path.

“Hurricanes now produce more economic harm than they have in the past for the same exact storm, because there's just more value at risk,” Gritzo says.

Water – from rain and coastal storm surge – is a tougher challenge

Hurricanes and tropical storms bring high winds, heavy rains and coastal storm surges. The engineering solutions for wind are relatively straightforward to implement. There’s good evidence from previous storms about the benefit of things like roof fasteners. Our clients can learn about the latest FM Approved installation recommendations by using RoofNav.

Water is a more difficult challenge, Gritzo says. And sea level rise only adds to the problem of storm surge.

Says Gritzo: “You can fasten down a roof, you can board up the windows to protect against wind. But how are you going to keep a wall of water away from your facility when it comes in? That's harder. You've got to build barriers, they’ve got to be tested, they’ve got to be strong.”

But there are steps our clients can take to prepare for hurricane season

At FM, we believe resilience is a choice. This is especially true for the 2024 Atlantic hurricane season and hurricane seasons to come, even for those more difficult challenges.

Here are a few steps our clients – and any business – should consider, Gritzo says:

• Build natural hurricane protections to knock down storm surge, like stone, coral or plants.
• Create a “sacrificial” first floor free of expensive equipment that would be damaged in a flood.
• Look carefully at vulnerable coastline areas when acquiring new facilities or getting rid of old ones.
• Work with neighbors on places to pump water in the event of flooding and rain.
• Consult the latest FM Approved solutions for wind, water and floods.
• Shorter-term steps include checking roof drains to make sure they’re clear of debris and testing emergency generators.

All of those require investment. That’s where FM’s Membership Credit and Resilience Credit can come into play, Gritzo says. FM announced a US$1.4 billion Membership Credit this year and a US$357 million Resilience Credit for clients in 2023.

“Our risk managers are really good about redirecting that to big risk issues,” Gritzo says. “This is the ideal year to double down on those efforts.”