Scattered to numerous monsoon thunderstorms developed across portions of south central Arizona, including the greater Phoenix metropolitan area, on August 3rd. Some of the thunderstorms generated intense rainfall with peak rain rates approaching 2 inches per hour. The heavy rains led to multiple episodes of flooding and flash flooding during the afternoon and evening hours. Heavy rains led to evening flash flooding of the Delaney Wash near Tonopah which resulted in the closure of 411th Avenue. Flash flooding was also observed in Queen Creek as the rapidly rising Sonoqui Wash near Hawes Road closed various low water crossings. No injuries were reported due to the flooding.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 17:30:00 to 03-AUG-17 20:30:00 (MST-7)
Location: (PHX)SKY HARBOR ARPT
Flood cause: Heavy Rain
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Scattered to numerous showers and thunderstorms developed across the greater Phoenix area during the afternoon hours on August 3rd, and some of the storms across the central and northern portions produced locally heavy rains with peak rain rates approaching 2 inches per hour. The intense rains led to episodes of flash flooding in areas ranging from central Phoenix, around Sky Harbor airport, northeast into Paradise Valley. At 1739MST, a trained spotter 2 miles west of Scottsdale reported water flooding the streets and rapidly encroaching an apartment located at the intersection of 60th Street and Thomas Road. At 1743MST, a public report indicated bumper deep water at the intersection of 44th Street and Indian School Road in central Phoenix. At 1746MST a public report via Twitter was received, indicating that flash flooding had caused street flooding and manhole covers to be blown from the ground near terminal 4 at Phoenix Sky Harbor Airport. Finally, at 1755MST, another public report via Twitter was received; it reported flash flooding about 1 mile southeast of Paradise Valley. Water was reported to be one foot deep on Scottsdale Road near the intersection of McDonald and Camelback Roads. No injuries were reported due to the flash flooding. A Flash Flood Warning was in effect at the time of the flooding; it was issued at 1728MST and was in effect until 2030MST.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 17:00:00 to 03-AUG-17 20:00:00 (MST-7)
Location: PHOENIX DEER VLY ARP
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Scattered monsoon thunderstorms developed across the northern portion of the greater Phoenix area during the afternoon  hours on August 3rd and some of the stronger storms affected communities such as Deer Valley. The storms produced locally heavy rains with peak rain rates well above one inch per hour and the rains resulted in episodes of flash flooding as area washes filled up and ran swiftly. According to a mesonet observation, flash flooding occurred 6 miles north of Deer Valley. At 1755MST, North Valley Parkway was flooded at the Sonoran Wash. The timing of the flooding was based on a Maricopa County Flood Control stream gage located upstream of the road crossing. A Flash Flood Warning was in effect at the time of the flooding; it was issued at 1655MST and it was in effect through 2000MST. No injuries were reported due to the flash flooding.

Flash Flood in PINAL, ARIZONA
From 03-AUG-17 18:30:00 to 03-AUG-17 21:30:00 (MST-7)
Location: ARIZOLA
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: County Official

Scattered thunderstorms developed across the northern portion of Pinal County during the evening hours on August 3rd, and some of the stronger storms affected areas around the town of Casa Grande. One of the primary weather hazards was intense rainfall which led to episodes of flash flooding over the lower deserts; the flooding caused roads to become impassable and resulted in various road closures. According to the city of Casa Grande Public Works Department, Overfield Road between Florence Highway 287 and Selma Highway was closed due to the high water. A Flash Flood Warning was in effect for the area during the flooding; it was issued at 1858MST and was cancelled at 2133MST.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 18:30:00 to 03-AUG-17 21:00:00 (MST-7)
Location: MOBILE
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorms developed across portions of the south-central deserts during the evening hours on August 3rd, and some of them affected areas to the southwest of Phoenix from the town of Maricopa westward towards Gila Bend. The storms generated locally heavy rain near Highway 238 between Mobile and Gila Bend which led to flash flooding along the highway. There are a number of washes that cross the highway and it does not take excessive amounts of rain to cause the washes to flood and impact the highway. According to a public report, at 1944MST flash flooding was occurring on Highway 238 between Mobile and Gila Bend, and a Flash Flood Warning was in effect at the time of the reported flooding.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 20:15:00 to 03-AUG-17 23:30:00 (MST-7)
Location: WINTERSBURG
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Scattered to numerous showers and thunderstorms affected much of the south-central deserts and the greater Phoenix area during the afternoon and evening hours on August 3rd. Some of the storms over the far western portions of Phoenix area produced locally heavy rains that led to episodes of flash flooding. Heavy rains led to flash flooding within desert washes such as the Delaney Wash. At 2025MST streamflow data indicated that the Delaney Wash was peaking and an Areal Flood Warning was issued for areas around the town of Tonopah. According to a report from the public, at 2023MST flow was observed across 411 Avenue. By roughly 2100MST, 411 Avenue was flooded near the Salome Highway as reported by Maricopa County Department of Transportation. Partly due to continued flow through Delaney Wash, the flood warning was allowed to continue through 2330MST.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 18:00:00 to 03-AUG-17 21:00:00 (MST-7)
Location: CHANDLER HGTS
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Scattered thunderstorms, some with locally heavy rain, developed across the southeast portion of the greater Phoenix area during the late afternoon and early evening hours on August 3rd. Some of the stronger storms affected areas around the community of Queen Creek and the intense rain led to episodes of flash flooding as area washes quickly filled up with swiftly moving water. At about 1830MST, a mesonet station one mile southwest of Queen Creek reported a very rapid rise in the Sonoqui Wash near Hawes Road. The depth of the flow was about 2 feet at the crest. The flooding in the wash impacted local road crossings in the area. Fortunately no injuries occurred due to the flash flooding. A Flash Flood Warning was in effect during the flooding; it was issued at 1803MST and was cancelled at 2033MST.

Flash Flood in MARICOPA, ARIZONA
From 03-AUG-17 17:30:00 to 03-AUG-17 20:30:00 (MST-7)
Location: GUADALUPE
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

Scattered to numerous thunderstorms developed across the central and southeast portions of the greater Phoenix metropolitan area during the afternoon hours on August 3rd, and some of the stronger storms generated intense rainfall with peak rainfall rates in excess of 4 inches per hour. At about 1800MST, a trained spotter in central Tempe near the intersection of Southern Avenue and McClintock Road measured 2.35 inches within 30 minutes. The intense rainfall easily led to episodes of flash flooding, especially given the extreme amounts of asphalt and concrete present in the area. At 1808MST, the Arizona Department of Highways reported flash flooding on the Superstition Freeway; the heavy rains caused the freeway to become flooded at McClintock Avenue in central Tempe. At 1816MST, the Arizona Department of Highways reported flash flooding further to the west as Highway 60, the Superstition Freeway, was flooded at the Mill Avenue underpass.  Shortly thereafter, at 1826MST, local broadcast media reported that flash flooding resulted in the closure of Mill Avenue just north of Broadway Road. A Flash Flood Warning was in effect at the time of the flooding; it was issued at 1728MST and was valid through 2030MST. No injuries were reported due to the flash flooding.