The article discusses the impact of heavy smoke from forest fires in the Amazon on cloud formation and precipitation. The smoke reduces cloud droplet size, delays the onset of precipitation, and suppresses low-level rainout and aerosol washout, allowing water and smoke to be transported to upper levels. This elevation of precipitation onset leads to more intense thunderstorms, large hail, and the possibility of overshooting cloud tops into the stratosphere. The study, conducted during the dry season in 2002, involved detailed measurements of aerosol properties, cloud droplet size distribution, and precipitation under various conditions, from clean air masses to smoky and pyro-clouds. The results show that while smoke suppresses surface heating and evaporation, it also stabilizes the lower troposphere, reducing convective clouds and precipitation. The microphysical effects of aerosols on clouds and precipitation are significant, with reduced droplet size in smoky clouds compared to clean air. The study highlights the complex interactions between smoke, clouds, and precipitation, and their potential impacts on regional and global climate systems.The article discusses the impact of heavy smoke from forest fires in the Amazon on cloud formation and precipitation. The smoke reduces cloud droplet size, delays the onset of precipitation, and suppresses low-level rainout and aerosol washout, allowing water and smoke to be transported to upper levels. This elevation of precipitation onset leads to more intense thunderstorms, large hail, and the possibility of overshooting cloud tops into the stratosphere. The study, conducted during the dry season in 2002, involved detailed measurements of aerosol properties, cloud droplet size distribution, and precipitation under various conditions, from clean air masses to smoky and pyro-clouds. The results show that while smoke suppresses surface heating and evaporation, it also stabilizes the lower troposphere, reducing convective clouds and precipitation. The microphysical effects of aerosols on clouds and precipitation are significant, with reduced droplet size in smoky clouds compared to clean air. The study highlights the complex interactions between smoke, clouds, and precipitation, and their potential impacts on regional and global climate systems.