Radar is an important nowcasting tool for recognizing flooding potential. Flooding occurs when too much rain falls over a given time period for the ground surface to support. The flooding potential will be greater when storms move over previously saturated land, snowmelt combines with rainfall or rain falls over land that has a low permeability. Any of the following seen on radar can produce flash flooding especially if the land is already saturated: 1. Training thunderstorms- thunderstorms developing and moving over the same areas that previously had thunderstorms. 2. Very intense slow moving thunderstorms- a single slow moving thunderstorm can produce several inches of rainfall per hour. 3. Consistent rain- rain (especially heavy rain) falling over an extended period of time. |