Thunderstorms with heavy rain developed across much of south-central Arizona during the evening hours on July 23rd and many of them affected the greater Phoenix metropolitan area, especially the eastern and southeast portion. Heavy rain led to episodes of both urban flooding and flash flooding, impacting communities such as San Tan, Apache Junction, Queen Creek and Casa Grande. Peak rain rates, as observed by a number of trained weather spotters, reached or exceeded 1.5 inches per hour. The heavy rain led to the issuance of multiple Flood Advisory and Flash Flood Warning products for the south-central deserts. Fortunately, no injuries resulted from the more significant flooding episodes. Additionally, one of the storms in the Phoenix area generated gusty damaging microburst winds which blew a tower onto a house just to the northeast of Phoenix Sky Harbor Airport.

Thunderstorm Wind in MARICOPA, ARIZONA
From 23-JUL-17 19:45:00 to 23-JUL-17 19:45:00 (MST-7)
Location: PAPAGO AAF ARPT
Magnitude: 56.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Amateur Radio

Strong thunderstorms developed over portions of the greater Phoenix area during the evening hours on July 23rd and although heavy rain was the primary weather threat, one of the storms did produce strong gusty and damaging outflow winds in the heart of downtown Phoenix. At 1945MST, an amateur radio operator reported that gusty microburst winds, estimated to be as high as 65 mph, blew down a tower. The tower then fell upon a house. This occurred about 3 miles northeast of Phoenix Sky Harbor airport. No injuries were reported.

Flash Flood in MARICOPA, ARIZONA
From 23-JUL-17 19:30:00 to 23-JUL-17 22:15:00 (MST-7)
Location: MOBILE
Flood cause: Heavy Rain
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Department of Highways

Thunderstorms with heavy rain developed across the far southern portion of the greater Phoenix area during the evening hours on July 23rd; locally heavy rains with rain rates well in excess of one inch per hour led to episodes of flooding as well as flash flooding. One of the more vulnerable areas was highway 238 between the town of Maricopa and Gila Bend, especially near the town of Mobile. Many washes run across the highway and are prone to flash flooding during heavy rains. According to the Arizona Department of Highways, at 1955MST flooding was occurring along Highway 238 near the town of Mobile and the road was closed. A Flash Flood Warning was in effect at the time of the flooding, and the warning remained in effect through 2215MST. Although rains and associated flash flooding threats had largely ended by 2215MST, mud and debris would likely remain on the road into the morning hours the next day before crews would be able to re-open the highway.

Flash Flood in PINAL, ARIZONA
From 23-JUL-17 18:30:00 to 23-JUL-17 22:45:00 (MST-7)
Location: SACATON
Flood cause: Heavy Rain
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorms with heavy rain developed across much of the eastern and southeastern portions of the greater Phoenix area during the evening hours on July 23rd. The heavy rain led to episodes of urban flooding as well as flash flooding, affecting communities such as San Tan Valley and Queen Creek. At 1905MST, a trained spotter 9 miles southeast of Queen Creek measured 0.88 inches of rain within 30 minutes along the Hunt Highway in San Tan Valley. This intense rainfall led to flash flooding; at about the same time another trained spotter 5 miles southeast of Queen Creek reported that very heavy rains caused low water crossings in San Tan Valley to become flooded. Additionally, at 2002MST another trained spotter 7 miles southeast of   Queen Creek measured nearly 1.5 inches of rain in one hour, further illustrating the intense nature of the evening rainfall. He also reported flash flooding at 2043MST, at the intersection of West Judd Road and North Brenner Pass Road. As of 2039MST, public reports indicated that parts of Empire Road and Riggs Road were closed due to the flash flooding. Fortunately, no injuries were reported due to the flash flooding.