Whilst to most, 01 December marks the countdown towards the festive season, to others on the other side of the Atlantic, it also marks the end of the Hurricane Season (officially on 30 November).
Initial Forecast vs. Actual Season
Forecast Expectations: Back in May 2024, experts from NOAA and Colorado State University predicted an above-average hurricane season due to warmer-than-usual sea surface temperatures and a shift from El Niño to La Niña conditions.
The forecast anticipated was of:
- 17-25 named storms
- 8-13 hurricanes
- 4-7 major hurricanes (cat 3 and above)
The actual season concluded with:
- 18 named storms
- 11 hurricanes
- 5 major hurricanes
Early Warnings
The season started when Tropical Storm Alberto formed on June 19. However, shortly after, Hurricane Beryl shattered records as the earliest Cat 5 storm on July 2.
Beryl wreaked havoc across the Caribbean, flattening islands and causing storm surges in Texas and Louisiana. The storm caused over $6 billion in insured losses and set the tone for what was expected to be a hyperactive season.
An Unexpected Lull
Despite the early signs of an extraordinary season, the Atlantic entered a surprisingly quiet phase between mid-August and mid-September — traditionally the peak of hurricane activity – there were no major storms.
This lull puzzled experts, as sea surface temperatures remained stubbornly high, and El Niño conditions, which typically suppress hurricane formation, subsided.
Whilst much debate is ongoing, experts believe this was due to:
- A northward shift of the West African monsoon, pushing storm seeds into less favourable areas, and
- Increased Saharan dust in the atmosphere, which hindered storm development.
A Final Fury
However, activity roared back after September 25, with seven storms forming—the most on record for the late season.
Hurricane Helene (Category 4) formed on September 24 and made landfall shortly after in Florida’s Big Bend region bringing catastrophic flooding and wind damage to areas in western North Carolina, with rainfall exceeding 30 inches in some areas and causing over $12 billion in insured damages. Having claimed the lives of 150 people Helene is now the deadliest hurricane in the U.S. hurricane since Katrina (2005).
To make matters worse, Helene was closely followed by Hurricane Milton (Category 5). Having formed in the Gulf of Mexico in early October 2024, the storm rapidly intensified and made landfall on Florida’s west coast, causing significant storm surges, widespread flooding and a record-breaking 46 tornadoes. With maximum sustained winds of 180 mph at peak intensity, Milton was among the strongest hurricanes of the season and highlighted the increasing frequency of rapid intensification with insured losses estimated at over $10 billion.
Lessons Learned and Future Outlook
Overall, the insurance industry faced over $40 billion in economic damages.
Following the strongest hurricane on record at the beginning of this year’s Season, it appears human-induced climate change is playing a significant role in rising temperatures on both land and in the ocean, resulting in the rapid intensification of storms.
- Storms Becoming More Extreme: While the forecast was largely accurate, the season underscored a troubling trend: storms are becoming more intense each year. Hurricane Milton, for example, intensified by 95 mph in just 24 hours, faster than any other storm in the Gulf of Mexico.
- New Hurricane Scale: Discussions are underway about introducing a new scale for categorizing the most extreme hurricanes, potentially moving beyond the current Saffir-Simpson Scale to a Cat 6+
- Global Warming Concerns: With global temperatures projected to rise by 3 degrees Celsius, the situation is expected to worsen. This escalation calls for urgent climate action to mitigate future risks.
- Intense Rainfall: Heavy rains lead to inland flooding and overwhelmed drainage systems resulting in more environmental concerns. Warmer temperatures allow for more humidity in the atmosphere, resulting in record rainfall levels, as experienced throughout Europe most of the summer. A shows that climate change increased rainfall from Milton by 20-30%.
- Rising Sea Levels: Even with limited climate change, some sea-level rise is inevitable. This will exacerbate flooding risks and potentially displace millions following the loss of habitable land in flood-prone areas.
- Hurricane-Induced Storm Surges: Coastal flooding from storm surges is a primary risk during hurricanes. Without protective measures, these surges can devastate communities.
- Florida’s Continued Vulnerability: Florida remains a hotspot for hurricane impacts, with rising water levels exacerbating flood risks. The 2024 season reaffirmed the need for robust coastal defences or a rethinking of how our cities are shaped, as well as enhanced preparedness strategies. More resilient construction will be required in the future should Floridians wish to cohabit with an ever-longer and more extreme hurricane season. Ideas such as sponge cities, floating housing, etc. are much needed to rethink how coastal cities can continue to thrive.
- Lack of coverage: Due to vulnerabilities, some homeowners are experiencing intensified challenges, leaving many without viable self-insurance options. This has led to heightened demand for coverage in these markets, even as economic pressures persist, with the potential return of parametric-style coverage.
“2024 hurricane season impact summary compared to forecast lessons learned future outlook” – bing.com
NOAA — NOAA predicts above-normal 2024 Atlantic hurricane season | National Oceanic and Atmospheric Administration – noaa.gov
Climate Central — Climate change increased wind speeds for every 2024 Atlantic hurricane: Analysis | Climate Central – climatecentral.org
KESQ — Visualizing how the 2024 hurricane season compares to past years – KESQ – kesq.com
https://www.climatecentral.org/report/2024-hurricane-attribution
https://www.ospo.noaa.gov/products/ocean/cb/sst5km/?product=ssta
https://www.noaa.gov/news-release/noaa-predicts-above-normal-2024-atlantic-hurricane-season