Scattered to numerous showers and thunderstorms moved across portions of the south central deserts, including northwestern Maricopa county and eastern La Paz county, during the morning hours on September 10th.  The atmosphere remained very moist and rather unstable and locally heavy rainfall occurred which led to episodes of flash flooding and flooding which continued into the afternoon. Heavy rainfall that had occurred the previous day exacerbated the flooding problems. Many washes were running heavily including the Centennial Wash near Wenden, as well as local washes across northwestern Maricopa county north of Interstate 10. Other areas affected included the Grand Avenue corridor from Wittmann and Circle City northwest towards Wickenburg. Both Flash Flood Warnings and Areal Flood Warnings were issued due to the flooding.

Flash Flood in LA PAZ, ARIZONA
From 10-SEP-13 10:00:00 to 10-SEP-13 14:00:00 (MST-7)
Location: WENDEN
Flood cause: Heavy Rain
Property damage: 25.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorms with locally heavy rainfall developed once again over portions of La Paz county during the morning hours on September 10th and as a result, flash flooding developed in the Centennial Wash. Previous heavy rains over the past day or two simply exacerbated the flow down Centennial Wash and as a result a Flash Flood Warning was issued at 1102MST for east central La Paz county including the communities of Wenden, Salome and Harcuvar. According to La Paz county Emergency Management and Sheriff's Offices, excessive storm runoff into the wash raised the water level significantly and flash flooding was occuring, threatening properties along the wash banks and leading to limited evacuations. Many roads in the Wenden area were closed as a result of flow through the wash.

Flood in LA PAZ, ARIZONA
From 10-SEP-13 14:00:00 to 10-SEP-13 21:45:00 (MST-7)
Location: HARCUVAR
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Thunderstorms with locally heavy rain decreased across eastern La Paz county during the afternoon hours on September 10th. However, due to the heavy rains that had occurred over the past couple of days, there was still significant flow in the Centennial Wash running though Wenden, affecting communities such as Salome. Local law enforcement indicated that many roads in Wenden were closed due to flow in Centennial Wash, and the stream gage in the wash reported 4 feet of elevation at 1345MST. Given the continued runoff the water level had the potential to rise even further into the afternoon thus increasing the likelihood of additional roads and low lying areas over eastern La Paz county to become inundated. An Areal Flood Warning was issued for east central La Paz county, including Wenden, from 1400MST until 2145MST.

Flash Flood in MARICOPA, ARIZONA
From 10-SEP-13 10:30:00 to 10-SEP-13 13:30:00 (MST-7)
Location: CIRCLE CITY
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Law Enforcement

During the late morning of September 10th thunderstorms developed from north of Wickenburg southward towards the northwestern fringes of the greater Phoenix area. They produced locally heavy rainfall; a flood control gage just east of Wickenburg measured 1.25 inches of rain within 15 minutes ending at 1134MST and another gage in Circle City measured 1.26 inches in less than one hour. Flash flooding resulted across portions of north central Maricopa county and by 1125MST a Flash Flood Warning was in effect. Radar and gage data indicated that rainfall rates approached 2 inches per hour in the area from Circle City northwestward towards Wickenburg; at 1233MST a Maricopa County Sheriff's deputy reported flash flooding in the Community of Circle City.  Heavy rains continued into the early afternoon and then gradually tapered off. Due to the persistent runoff impacting area roads as well as heavily running washes, an Areal Flood Warning was then issued at 1330MST for the Grand Avenue Corridor extending from Wittmann to Wickenburg and it continued until 2130MST.