An Atlantic hurricane season is about to end without a single hurricane making landfall in the United States - a rare thing for a decade. However, the depressions and storms that form outside the ocean are so strong that they issue a clear warning about the future of the climate and the ocean warming rapidly.
Even if the center of the storm does not overflow directly to shore, the destructive power is still present. The remnants of Barry caused severe flooding in the mountainous areas of Texas, while Chantal brought deadly flooding to North Carolina. This shows the reality that without landfall, storms are still capable of causing disasters in the context of a humder atmosphere and increased extreme rainfall globally.
Philip Klotzbach, a hurricane expert at Colorado State University, called it a strange hurricane season. The three storms have accelerated to a Category 5 maximum. Four storms reached Category 4 and four others intensified extremely rapidly, meaning the wind speed increased by at least 56 km/h in just 1 day.
Not much in quantity, but they are among the strongest groups of the strongest. As long as one of those extremely large storms makes landfall in a residential area, the damage will far exceed the many weak storms combined, Klotzbach warned.
A total of 13 storms have formed, slightly below the long-term average, which is also lower than initial forecasts that the season could see up to 19 storms.
The common point of strong storms this year is underwater: Ocean temperatures are too high. More than 80% of the Atlantic region recorded above-average temperatures, among the highest since 1958. Nearly 40% of the Atlantic basin is in the top 10% hottest temperature ever recorded.
This warming helps storms maintain their intensity, even continue to get stronger as they move, because instead of meeting the cold water layer, they can still absorb heat from the warm water layer below.
However, high sea surface temperatures are not enough to create storms without atmospheric instability - that is, the large gap between warm ocean and the cold atmosphere above.
This year, in some areas, upper-level air is unusually warm, reducing temperature differences and causing fewer new storms to form than expected, despite the very hot ocean.
In contrast, in the Caribbean - where superstorm Melissa reached historic destructive strength in Jamaica - a large temperature difference created conditions for a truly explosive monster storm.
There is no sign that ocean temperatures will drop by 2026. This factor will continue to be a catalyst for storm intensity next season.
Another factor - La Nina - which contributes to making the 2024-2025 hurricane season more favorable for strong storms, is forecast to weaken early next year.
Rarely, there have been two consecutive years without hurricanes making landfall in the United States, which has only occurred six times since 1851. But the absence of storms on land does not bring a sense of safety. On the ocean, their strength is changing less in quantity, but stronger, more intense, and leaves a warning for the upcoming hurricane seasons.
