Persistent Multi-Scale Consistency in Best-Track Intensity Evolution and Rapid Intensification in Atlantic Tropical Cyclones (1851–2024)

Nathan Howell 

Rapid intensification (RI), commonly defined as an increase in maximum sustained wind speed of at least 30 kt within 24 h, remains one of the most challenging aspects of tropical cyclone forecasting.

This study evaluates whether persistent multi-scale consistency in best-track intensity evolution is statistically associated with RI occurrence across the full Atlantic historical record. A minimal, forward-only diagnostic is constructed from HURDAT2 using causal rolling means of maximum sustained wind speed at multiple timescales and a directional-agreement rule across scales. The method uses only current and prior best-track intensity values and is applied uniformly to 1,991 Atlantic tropical cyclones from 1851 to 2024.

Storms exhibiting longer durations of persistent multi-scale agreement form a conditionally enriched subset with substantially elevated RI occurrence. As persistence increases, RI probability rises from a basin-wide baseline of approximately 26% to about 60% for storms with at least 140 h of persistence and to about 67% for storms with at least 168–270 h of persistence.

The diagnostic is not interpreted as a direct measure of inner-core structure and is not proposed as an operational forecast tool. Instead, it provides a reproducible long-record statistical diagnostic derived solely from best-track data. The results indicate that prolonged multi-scale consistency identifies a subset of storms with substantially elevated RI likelihood and motivate further comparison with higher-resolution structural observations.