Thunderstorms developed across much of south-central Arizona during the evening hours on August 9th and as is typical during the monsoon, they brought gusty and damaging outflow winds along with very heavy rain and flooding to the deserts. Peak rainfall rates were in excess of 2 inches per hour which led to some urban flooding in the greater Phoenix area. There were also instances of wind damage; trees were down in areas ranging from north of Sun City to southeast of Phoenix, in communities such as Chandler and Queen Creek. Also, at about 2030MST, strong winds in the Lake Pleasant area snapped ropes holding down some of the boats and even caused damage to one of the docks.

Thunderstorm Wind in MARICOPA, ARIZONA
From 09-AUG-18 21:14:00 to 09-AUG-18 21:14:00 (MST-7)
Location: BEARDSLEY
Magnitude: 51.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Thunderstorms with strong gusty outflow winds developed across the northwest portion of the greater Phoenix metropolitan area during the evening hours on August 9th; some of the storms affected areas around Sun City West. At 2114MST an automated Flood Control District weather station west of Sun City West measured a wind gust to 59 mph. The station was located at McMicken Dam near Grand Avenue and the Loop 303 freeway and near the Cimarron Golf Club.

Thunderstorm Wind in MARICOPA, ARIZONA
From 09-AUG-18 20:30:00 to 09-AUG-18 20:30:00 (MST-7)
Location: BEARDSLEY
Magnitude: 56.00 EG
Property damage: 2.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorms with gusty and damaging outflow winds moved across the northwest portion of the greater Phoenix area during the evening hours on August 9th; some of the stronger storms affected areas to the east of Wittmann and north of Sun City West. At 2030MST a member of the public reported that tree limbs with diameters of between 6 and 8 inches were snapped by gusty winds estimated to be as high as 65 mph. The snapped limbs were located near West Lone Mountain Road and Westland Road in the community of Vistancia and north of the Trilogy Golf Club.

Thunderstorm Wind in MARICOPA, ARIZONA
From 09-AUG-18 20:29:00 to 09-AUG-18 20:29:00 (MST-7)
Location: NEW RIVER
Magnitude: 52.00 EG
Property damage: 30.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorms with strong gusty outflow winds developed to the north of the greater Phoenix metropolitan area during the evening hours on August 9th; some of the stronger storms affected the southern portion of Lake Pleasant. According to a report from the public, at 2029MST gusty winds estimated as high as 60 mph snapped a number of ropes that were holding boats to the docks on the south shore of Lake Pleasant. The gusty winds even lifted up one of the docks and when the dock landed, it came down on some of the boats. No injuries were reported, including those that were on any of the boats.

Heavy Rain in MARICOPA, ARIZONA
From 09-AUG-18 23:00:00 to 09-AUG-18 23:55:00 (MST-7)
Location: HARMONY VILLA
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Thunderstorms with locally heavy rainfall developed across the central and eastern portion of the greater Phoenix metropolitan area during the late evening hours on August 9th. Rainfall rates with the stronger thunderstorms reached or exceeded 3 inches per hour; a Flood Control District gauge 2 miles east of East Mesa measured 1.54 inches within a 30 minute period ending at 2335MST. At 2335MST a trained spotter located 3 miles north of East Mesa reported curb to curb residential flooding near the intersection of Power Road and McDowell Road. He indicated that one inch of rain fell within 20 minutes, and peak rain rates exceeded 5 inches per hour for a brief period. Despite the intense rains, Flash Flooding was not reported as of 2335MST.

Thunderstorm Wind in MARICOPA, ARIZONA
From 09-AUG-18 23:10:00 to 09-AUG-18 23:10:00 (MST-7)
Location: HIGHTOWN
Magnitude: 61.00 EG
Property damage: 10.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorms developed over the southeastern portion of the greater Phoenix metropolitan area during the evening hours on August 9th, and some of the stronger storms generated gusty and damaging outflow winds that affected the community of Chandler. At 2310MST, a member of the public reported that a very large tree was downed about 3 miles northwest of Chandler, just south of the intersection of McClintock Drive and Warner Road. The diameter at the base of the tree was about 12 inches. Wind gusts were estimated to be as high as 70 mph. When the tree fell it landed on a house; fortunately there were no reports of any injuries.

Thunderstorm Wind in MARICOPA, ARIZONA
From 09-AUG-18 23:45:00 to 09-AUG-18 23:45:00 (MST-7)
Location: GERMANN
Magnitude: 56.00 EG
Property damage: 6.00K
Crop damage: 0.00K
Reported by: Public

Thunderstorms developed across the southeast portion of the greater Phoenix area during the late evening hours on August 9th; some of the stronger storms produced gusty and damaging outflow winds that affected communities such as Gilbert. According to a report from the public, at 2345MST gusty wind estimated to be as high as 65 mph downed a number of trees about 2 miles to the southwest of the Phoenix Mesa-Gateway Airport. The trees were downed near the intersection of Power Road and Germann Road. No injuries were reported.