Photograph an immense summer prairie beneath well-defined mammatus clouds shortly before a thunderstorm. Rounded cloud pouches fill most of the sky, shifting from deep charcoal overhead to lead blue and a restrained peach afterglow near the distant horizon. Below, gold-green grass bends in one direction under gusty wind, a narrow meandering creek reflects the sky, and one small unoccupied wind-powered water pump provides scale. Use a landscape 4:3 low 18mm ultra-wide composition with the horizon in the lower quarter, making the cloud structure dominant while foreground grass and the creek create leading lines. Natural diffuse light should reveal humid air, layered cloud depth, realistic vegetation, and subtle water texture without artificial drama. No tornado, visible lightning, readable text, people, animals, logos, watermark, excessive HDR, fantasy colors, or duplicated horizon.