Hurricane disturbance leads to elevated wildfire activity in the Gulf Coast region U.S.A.

Building on long-standing hypotheses of a hurricane-fire interaction, this study assesses empirical evidence for hurricane-driven increases in wildfire activity along the Gulf Coast of the United States. It has been proposed that wildfire risk is elevated post-hurricane due to increased fuel accumulation and alterations to forest microclimates associated with treefall (e.g., increased radiation, temperature, aridity). While isolated studies have identified evidence supporting this relationship using premodern proxy data, an analysis using modern empirical data is lacking. This study addresses this gap by using spatial analysis of contemporary hurricane and wildfire data to evaluate changes in wildfire activity following hurricane landfall events. Thirty hurricanes that made landfall between 1992 and 2019 (Category 1 to 5) were analyzed alongside wildfire data surrounding their path of destruction from the five years before and after each storm. In the five years after hurricanes, increases were seen in both the number of wildfires and total area burned, though spatial and temporal variation are apparent along the coastline. Of the three subregions studied, the Florida Peninsula experienced the largest increase in wildfire activity, primarily in the two and three years following hurricanes. Wildfire activity following select hurricanes is compared to fire weather index data to ensure observed trends are attributable to hurricane damage rather than background climatic factors. These results support the hypothesis of a hurricane-fire interaction and demonstrate that hurricanes continue to influence Gulf Coast fire regimes in the modern era, despite widespread fire suppression and prescribed burning efforts.