Plume‐Coupled Long‐Range Spotting Drove the Explosive Spread of the 2018 Camp Fire

Abstract Extreme fire spread during the 2018 Camp Fire in northern California was driven by organized long‐range spotting tightly coupled to plume dynamics. Doppler radar and satellite observations reveal distinct regions of ember lofting and downwind fallout within the convective column, forming direct pathways for firebrand transport several (up to 10) kilometers ahead of the main fire front. These firebrands ignited dense clusters of new fires that merged into rapidly advancing lobes, producing abrupt surges in fire growth that exceeded expectations based on surface wind and fuel conditions alone. By integrating radar‐derived plume structure, infrared satellite imagery, and ground‐based ignition reports, this study provides one of the first high‐resolution, multi‐scale depictions of spotting behavior during an extreme wildfire. The reconstructed distribution of spot fire distances shows that most ignition occurred within 1–5 km of the fire front, but numerous events exceeded 5 km, including some at 8–10 km from active plume cores. These distances are notable relative to prior observational studies and highlight the capacity of organized plume structures to transport embers beyond conventional expectations. Spot fires were not random but aligned within coherent fallout zones shaped by plume dynamics and wind shear. These findings demonstrate that long‐range spotting was a dominant mechanism of Camp Fire spread and underscore the limitations of models that omit ember transport and fire–plume feedback. The results also highlight the potential of operational weather radar to identify active lofting and fallout regions in real time, offering a new observational basis for anticipating spotting‐driven acceleration.