Spatiotemporal hotspots of sequential tropical-cyclone multi-hazards in the North Atlantic Basin

Tropical-cyclone (TC) impacts often cascade when storms arrive in sequence or simultaneously, amplifying risk and recovery demands. We introduce an operational, threshold-based classification of TC-multi-hazards that is explicitly tailored to sequential TCs within a single hurricane season, was applied to basin, country and local. Using IBTrACS for the North Atlantic basin (1980–2023), we define four temporal dependencies—concurrent (<1 day), overlapping (1–7 days), consecutive (8–30 days), and within-season (>30 days within the same season)—and couple them with spatial dependencies based on landfall, tracks that intercept a 100-km buffer around countries or localities, and multiple landfalls. This framework is used to identify TC-multi-hazards hotspots and to characterize sequential intensity patterns in where the second TC is stronger than the first.

At the basin scale, 11% of the events are multiple-landfall-concurrent types, of which 88% is concentrated in the Greater Antilles, and 38% each overlapping and consecutive types. Though hotspots of the overlapping, consecutive and within-season types are mainly concentrated in the western Atlantic basin, no clear hotspot patterns were identified between types that include landfalls involving one TC compared to those involving multiple TCs.

 At the country scale, 49% of the events are buffer-consecutive types, which are found across the basin, with a high density in the Lesser Antilles. At the locality scale, buffer-consecutive events (the Lesser Antilles, Florida, Bahamas, Nicaragua) and buffer-within-season events (Gulf of Mexico, Cuba, and Mexican Caribbean) dominate this scale, representing 74% and 22% of the events, respectively.

This classification supports time-dependent recovery planning, enhances the design of early warning systems, and provides a crucial methodological link between generic multi-hazard types and practical TC risk management and insurance applications.