Flooding.

[Tigs]

a flash flood is an event that occurs within 6 hours . generally, flash flooding events develop rapidly and can occur anywhere water collects, especially areas of steep terrain, and water runoffs. flash floods rarely last more than 12 hours.

a flood is an event that occurs after 6 hours generally, flooding events usually take longer to develop and they usually occur along or near larger rivers. The duration of flooding events may extend longer than 24 hours, perhaps several days.