During the early morning hours on September 23rd, copious tropical moisture began to spread north and into south-central Arizona. A weather system dropping south out of Nevada began to act on the moisture, resulting in the development of numerous showers and thunderstorms. Some of the storms produced copious amounts of rain with peak rain rates in excess of 2 inches per hour. Many locations across the high terrain east of Phoenix measured more than 3 inches of rain during the morning hours. Multiple events of flash flooding occurred in locations such as Apache Junction, Tortilla Flat, Fountain Hills and terrain to the south and east of Lake Roosevelt. As an example, at 0730MST a local emergency manager reported that 7 homes were flooded in Roosevelt Estates as Campaign Creek overflowed its banks. Several Flash Flood Warnings were issued for areas to the east of Phoenix during the morning hours. In 2020, the Arizona Department of Transportation was awarded $10.7 million from the Federal Highway Administration to support the repair of roads and bridges damaged due to the numerous flash flooding events that occurred across Arizona on the 23rd.

Flash Flood in GILA, ARIZONA
From 23-SEP-19 06:00:00 to 23-SEP-19 10:45:00 (MST-7)
Location: ROOSEVELT GRPVN ARPT
Flood cause: Heavy Rain
Property damage: 200.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Copious amounts of tropical moisture spread northward and into the high terrain areas east of Phoenix during the early morning hours on September 23rd and as a result, numerous showers and thunderstorms developed. Many storm produced heavy rain with peak rain rates in excess of 2 inches per hour. The heavy rain resulted in episodes of flash flooding, affecting areas to the south and east of Lake Roosevelt including Tonto National Monument. At 0700MST a federal agency reported flash flooding on the upper cliff dwelling trail about 2 miles southeast of Roosevelt. Shortly thereafter, at 0730MST, a local emergency manager located 8 miles east-southeast of Roosevelt reported that 7 homes were flooded in Roosevelt Estates as Campaign Creek overflowed its banks. As much as 18 inches of water was reported in one of the houses. Fortunately there were no reports of injuries. Two Flash Flood Warnings were issued for the area, the first was issued at 0609MST and the second at 0652MST.

Flash Flood in MARICOPA, ARIZONA
From 23-SEP-19 05:00:00 to 23-SEP-19 10:00:00 (MST-7)
Location: TORTILLA FLAT
Flood cause: Heavy Rain
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Department of Highways

Copious amounts of tropical moisture spread northward and into south-central Arizona during the early morning hours on September 23rd, leading to the development of numerous showers and thunderstorms over higher terrain areas east of Phoenix. Locally heavy rain developed, with peak rain rates in excess of 2 inches per hour. By mid morning, a number of locations had already received more than 3 inches of rain. The  heavy rain led to episodes of flash flooding from Tortilla Flat eastward. At 0605MST, the Fish Creek USGS stream gage 5 miles east of Tortilla Flat reported an increase from 5 feet to 9.5 feet. At 0615MST, Arizona Department of Highways reported that State Route 88 was closed indefinitely between Tortilla Flat and State Route 188. The closure was due to flash flooding as well as debris across the road. Additionally, at 0748MST a member of the public reported flash flooding along Lewis and Pranty Creek near State Route 88. This occurred roughly 7 miles east of Tortilla Flat and south of Apache Lake. The report also indicated that water had jumped out of the creek's banks and was inundating one of the properties in the area. Multiple Flash Flood Warnings were issued during the morning and were in effect at the time of the flooding. No injuries were reported fortunately.

Flash Flood in MARICOPA, ARIZONA
From 23-SEP-19 08:00:00 to 23-SEP-19 12:15:00 (MST-7)
Location: FT MCDOWELL
Flood cause: Heavy Rain
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Fire Department/Rescue

Copious amounts of tropical moisture spread north and into south-central Arizona during the morning hours on September 23rd, allowing for the development of numerous showers and thunderstorms. Locally heavy rain occurred with peak rain rates in excess of 2 inches per hour at times, and the heavy rain led to flash flooding affecting areas such as Fountain Hills. As an example of the heavy rain that fell, at 0820MST a trained spotter located about 2 miles northeast of Fountain Hills indicated that 3.5 inches of rain had fallen over the past one hour and forty minutes resulting in minor flooding. Flash flooding soon developed and at 0900MST local fire and rescue reported that Ashford Wash in Fountain Hills had exceeded its banks. Flooding occurred at the intersection of El Pueblo Boulevard and Calico Drive. A Flash Flood Warning was issued for the area at 0818MST and was in effect at the time of the flash flooding.

Flash Flood in PINAL, ARIZONA
From 23-SEP-19 05:30:00 to 23-SEP-19 09:45:00 (MST-7)
Location: GOLDFIELD
Flood cause: Heavy Rain
Property damage: 40.00K
Crop damage: 0.00K
Reported by: Department of Highways

Copious amounts of tropical moisture spread north and into south-central Arizona during the early morning hours on September 23rd allowing for the development of numerous showers and thunderstorms. Many of the storms had heavy rain with peak rain rates in excess of 2 inches per hour. The heavy rain led to episodes of flash flooding across areas to the east and southeast of Phoenix including the communities of Apache Junction and East Mesa. According to the Arizona Department of Highways, at 0630MST flash flooding 3 miles northeast of Apache Junction resulted in State Route 88 becoming impassable at Mile Marker 199 along Weekes Wash. Flooding was also occurring along Palm Wash. In addition, at 0700MST local broadcast media reported a swift water rescue underway at the intersection of Main Drive and Mckellips Boulevard, about 3 miles northwest of Apache Junction. A Flash Flood Warning was issued for the area at 0541MST and was in effect during the flooding. No injuries were reported due to the flooding.

Flash Flood in MARICOPA, ARIZONA
From 23-SEP-19 05:00:00 to 23-SEP-19 09:45:00 (MST-7)
Location: DESERT SANDS
Flood cause: Heavy Rain
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Copious amounts of tropical moisture spread north and into south central Arizona during the early morning hours on September 23rd, resulting in scattered to numerous showers and thunderstorms. Peak rain rates with the stronger convective cells was in excess of 2 inches per hour; the heavy rain resulted in episodes of flash flooding east of Phoenix, affecting communities such as East Mesa and Apache Junction. According to a trained spotter located about 4 miles southeast of East Mesa, at 0525MST flash flooding caused several streets to flood and an area wash was filled with several feet of water. The flooding was west of Crismon Road and between Broadway and Southern. At 0630MST, local broadcast media reported that flash flooding 1 mile southwest of Apache Junction resulted in the closure of 16th Avenue between Delaware and Ironwood Drive. The flooding occurred when a wash flowed across the road. Finally, at 0700MST local broadcast media reported an episode of flash flooding 3 miles west of Apache Junction. The flash flooding necessitated a water rescue of a stranded vehicle just north of Main Street and near Signal Butte Road. No injuries were reported for any of the flash flooding incidents. A Flash Flood Warning was issued at 0541MST and the warning covered most of the flooding incidents.