Question

when does a drought occur​

Answer 1

Meteorologists predict drought based on precipitation patterns, stream flow, and moisture of soil over long periods of time. In the United States, droughts are most likely to occur in the Midwest and the South.

Hope it's helpful... ^_^

Answer 2

Explanation:

Droughts happen when there is not enough rain for a long period of time. It's not like a dry spell - there is so little precipitation (rain, snow, sleet or any kind of moisture) that a whole region starts to dry out. Sometimes a drought takes decades to develop fully and they are very difficult to predict.