SmokePath Explorer – a data driven smoke management tool to support prescribed fire planning in California, USA

SmokePath Explorer is a web-based decision-support tool for California, U.S.A. that quantifies smoke transport probability and population exposure risk across the state, enabling data-driven strategies to minimize impacts while advancing fire management effectiveness. SmokePath integrates the California and Nevada Smoke and Air Committee (CANSAC) high-resolution (2-km) 20-year reanalysis climatology with HYSPLIT trajectory modeling. A total of 1.3 billion transport trajectories were precomputed with initializations four times per day at four distinct height levels capturing diurnal variations and injection height influences across various prescribed fire scenarios to support probabilistic smoke projections. Within the SmokePath online dashboard, users can input fire parameters and select specific months or weeks to assess smoke transport risk. The tool generates risk-level smoke transport contours from precomputed data and summarizes key meteorological variables. The system also provides population exposure estimates, including the total affected population, the number of smoke-sensitive facilities (i.e. educational and healthcare), and impacted USPS ZIP codes. User feedback has been key to developing SmokePath, enhancing usability, data integration, and decision-making for prescribed fire planning. To assess SmokePath's efficacy, we conducted case studies across diverse regions and validated results against independent observation datasets. These use cases assessed the accuracy of the WRF-CANSAC reanalysis dataset, which serves as the meteorological input for fire weather climatology and trajectory modeling. The fire case studies focused on identifying optimal burn windows and quantifying smoke transport patterns from (i) large multi-day prescribed fires, (ii) short duration (single-day) pile burns, and (iii) burns across diverse regions with complex topographic features. In most cases, modeled transport probability aligned with satellite-observed smoke plumes, capturing predominant dispersion patterns. Stakeholder feedback further supported the tool's practical utility - 85% indicated they would use SmokePath for prescribed fire planning, and 62% found it useful during wildfires.<i>Implications</i>: With catastrophic wildfires on the rise, California is expanding fuel treatments, including prescribed fire. While essential for mitigation, prescribed burns release smoke that can harm public health if unmanaged. SmokePath addresses this challenge by providing evidence-based insights on plume behavior to guide short- and long-term planning. The tool helps land managers schedule burns to minimize community impact, especially for vulnerable populations, and supports wildfire response with rapid smoke risk information. By improving public communication and enabling protective actions, SmokePath advances both health protection and the strategic use of prescribed fire.