Interactions Between a High-Intensity Wildfire and an Atmospheric Hydraulic Jump in the Case of the 2023 Lahaina Fire

On 8 August 2023, a grass fire that started in the city of Lahaina, Hawai’i, grew into the deadliest wildfire in the United States since 1918. This wildfire offers a unique opportunity to explore the impact of high heat output on an atmospheric hydraulic jump and a downslope wind event. We conducted two WRF-SFIRE simulations to investigate these effects: one incorporating fire–atmosphere feedback and the other without it. Our findings revealed that, in the uncoupled simulation, the hydraulic jump moved inland significantly earlier than in the coupled simulation. This altered the wind pattern near the fire front in the uncoupled simulation, accelerating its lateral spread. The results suggest that fire–atmosphere interactions and their influence on near-fire circulation may be more intricate than previously understood. Specifically, while fire-induced wind acceleration is often linked to enhanced fire spread, this study highlights that, in cases where the lateral fire spread is dominant, fire-induced circulation may reduce cross-flank flow and inhibit the fire growth.