Flash Flood — Maricopa, Arizona

2012-07-31 · near New River, Maricopa, Arizona

Event narrative

Isolated strong thunderstorms developed across the northern portions of the greater Phoenix area during the afternoon hours on July 31st. During the late afternoon the storms congealed and intensified in the Anthem area, and they produced excessive rainfall which led to episodes of flash flooding. Radar indicated that peak rainfall rates were in excess of 3 inches per hour, and one weather observer measured more than 5 inches of rain within 90 minutes. According to the Anthem Fire Department and Rescue, the heavy rain filled up the Deadman Wash drainages in town and overflowed, leading to severe flooding in a number of homes. Much of the flooding occurred between 6 pm and 7 pm. At about 610 pm flood waters backing up in the wash overtopped a brick wall behind a home causing the wall to collapse. Flood waters then poured into the home, located at 40715 North Erickson Lane, causing severe flood damage. As the wall collapsed, the flood waters slammed into the homeonwner, carrying her across the yard and causing injuries to her.

Wider weather episode

Isolated strong thunderstorms developed across portions of the greater Phoenix area during the mid afternoon hours on July 31st. One storm produced a wind gust to 64 mph at the Deer Valley airport. The thunderstorms moved slowly north, then congealed and intensified over the community of Anthem. Very heavy rains, with rainfall rates in excess of 3 inches per hour, were observed and they led to episodes of flash flooding in the community of Anthem. One weather observer reported rainfall in excess of 5 inches in his rain gage. Flooding also occurred in the Deadman Wash near Interstate 17 to the west of Anthem.

View location on OpenStreetMap → (33.8455, -112.1416)

Source: NOAA Storm Events Database, event_id 395629. Narrative written by the NWS forecast office that issued the report.