Human activities have led to unprecedented global warming, making tropical cyclones (TCs) stronger over the past four decades (1, 2). Many of these intense storms undergo rapid intensification (RI), where wind speed increases by at least 30 knots within 24 hours, before making landfall (3, 4).

This phenomenon is particularly problematic, as it leaves little time for evacuation and preparation for the event, leading to greater damage and loss of life. For example, in October 2023, Hurricane Otis rapidly intensified from a tropical storm to a Category 5 hurricane within a single day and made landfall near Acapulco, Mexico. Otis was the strongest storm ever to make landfall in the eastern Pacific with catastrophic 143 knots winds (5). The hurricane caused about $16 billion worth of damage and at least 52 deaths (5).

Such abrupt changes in TC wind speed make it difficult, if not impossible, for models to reliably predict these events. Otis, for example, was one of the most poorly predicted RI events in recent decades, despite all the improvements of RI forecast tools (6). Hurricane Ian (2022) intensified to a Category 4 hurricane and made landfall on the Gulf coast of Florida with winds of 135 knots (7). Similarly, Category 5 super typhoon Goni (2020), which had winds of 170 knots at landfall, the strongest ever at landfall in recorded history (8), underwent RI while passing through the Philippine Sea. A common factor for all these cyclones is that they traversed a patch of ocean that exceeded 30°C along their trajectories before making landfall.

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Researchers looked at 1,600 tropical cyclones—the broader category of storms that includes hurricanes—that made landfall since 1981 and found those that went over the extra-hot water were more likely to intensify rapidly, a problem that’s becoming more frequent. This resulted in 60% more disasters that caused at least $1 billion in damage—adjusted for inflation—when they hit land, according to a study in Friday’s journal Science Advances.

Fig. 1. Global MHW characteristics.

Forty-one-year (September 1981 to October 2023) average properties of MHWs based on high-resolution (0.25° × 0.25°) gridded daily SST data obtained from the National Oceanic and Atmospheric Administration (NOAA) OI SST v2.1 dataset. (A) Mean SST anomaly (°C), (B) mean annual frequency (events per year), © mean annual duration (days per year), and (D) mean annual maximum intensity relative to 90th percentile (degrees Celsius per year). Note: This analysis covers only the MHWs occurring during TC activity seasons, i.e., May through November in the Northern Hemisphere and November through April in the Southern Hemisphere. (E) The seven active TC basins.

Fig. 3. Historical analysis of TCs based on the occurrence of RI and the presence of MHWs from 1981 to 2023.

This figure depicts the temporal evolution of TC frequencies over a period of 41 years worldwide and for the seven active TC basins: (A) Global, (B) East Pacific, ( C) North Atlantic, (D) Northwest Pacific, (E) North Indian, (F) Southwest Indian, (G) Australian, and (H) Southwest Pacific. Each subplot contains the total number of TCs in each category. The dashed lines show various trends in the events. The red line represents TCs that underwent RI and were influenced by MHWs, the green line represents MHW TCs without RI, the pink line represents non-MHW TCs that underwent RI, and the blue line represents non-MHW TCs without RI. The shaded area indicates a 95% confidence interval. Double asterisk indicates that the trend is significant (P ≤ 0.05).