Explain how the farms upriver were adding to the high nitrate levels. (Gizmo)

Farmers were adding high nitrate levels from many large corn farms along the river. ... During the drought, the farmers used extra fertilizer. As rained, the ammonia and nitrate from the fertilizer were washed into the river.

supercell thunderstorms are perhaps the most violent of all thunderstorm types, and are capable of producing damaging winds, large hail, and weak-to-violent tornadoes