Strong thunderstorms developed over the central Arizona deserts during the late afternoon and evening hours on July 31st. Initially the storms produced a dust storm that moved from northwest Pinal county into the Phoenix metropolitan area. The dust storm was followed by additional thunderstorms that brought damaging microburst winds and heavy rains to the central deserts including the greater Phoenix area. Damaging microburst winds also affected the area around Casa Grande.

Dust Storm in GREATER PHOENIX AREA, ARIZONA
From 31-JUL-11 18:35:00 to 31-JUL-11 20:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Several trained spotters in the greater Phoenix metropolitan area reported a dust storm during the evening hours on July 31st. The dust storm was spawned by thunderstorm outflow winds in excess of 40 mph. A trained spotter 5 miles east of Sun Lakes reported visibility less than one quarter mile in dense blowing dust at Gilbert and Riggs road at 640 pm. Winds were gusting to near 50 mph at the time. At approximately 730 pm, spotters near Firebird lake and at I-10 and Warner road reported a dust storm with visibilties below one quarter of a mile.

Thunderstorm Wind in PINAL, ARIZONA
From 31-JUL-11 17:45:00 to 31-JUL-11 17:45:00 (MST-7)
Location: STANFIELD
Magnitude: 78.00 EG
Property damage: 75.00K
Crop damage: 0.00K
Reported by: Law Enforcement

As reported by officers from the Casa Grande Police Department, thunderstorm microburst winds estimated to be near 80 knots severely damaged two mobile homes approximately 8 miles west of Casa Grande. No injuries were reported.

Thunderstorm Wind in PINAL, ARIZONA
From 31-JUL-11 18:24:00 to 31-JUL-11 18:24:00 (MST-7)
Location: CASA GRANDE
Magnitude: 56.00 EG
Property damage: 5.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong thunderstorms developed in the Casa Grande area during the late afternoon hours on July 31st. A trained weather spotter 2 miles east of Casa Grande reported an estimated wind gust to 65 mph. The strong microburst winds damaged the roof on a neighboring home.

Thunderstorm Wind in MARICOPA, ARIZONA
From 31-JUL-11 19:20:00 to 31-JUL-11 19:20:00 (MST-7)
Location: BUCKHORN
Magnitude: 50.00 EG
Property damage: 3.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A trained weather spotter in the Gilbert area reported that a large tree was downed near Higley and Baseline roads. The tree was downed by strong thunderstorm winds estimated to be around 50 knots. A former National Weather Service employee sent in a photo of another large tree that was downed at the intersection of Hunt and Gilbert roads.

Thunderstorm Wind in MARICOPA, ARIZONA
From 31-JUL-11 21:26:00 to 31-JUL-11 21:26:00 (MST-7)
Location: PHOENIX FARM AERO AR
Magnitude: 52.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Broadcast Media

Strong thunderstorms over central Phoenix produced damaging microburst wind gusts estimated by weather service radar to be approximately 60 mph.  As reported by several local media sources, the winds downed several power poles and damaged residential structures in the vicinity of 27th Avenue and Van Buren. The damage included backyard sheds as well as roof shingles. Damage occurred near 930 pm on the evening of July 31st.

Thunderstorm Wind in MARICOPA, ARIZONA
From 31-JUL-11 19:30:00 to 31-JUL-11 19:40:00 (MST-7)
Location: OCOTILLO
Magnitude: 60.00 EG
Property damage: 100.00K
Crop damage: 0.00K
Reported by: NWS Employee

Thunderstorms produced strong damaging microburst winds over portions of Gilbert during the early evening hours on July 31st. A former National Weather Service employee reported that extensive damage was done to the Solera subdivision. Microburst wind gusts estimated to be in excess of 60 knots, damaged at least 110 trees, with 67 of the trees blown down. Additional damage was done to various structures in the community, including a block wall that was blown down.

Heavy Rain in MARICOPA, ARIZONA
From 31-JUL-11 20:00:00 to 31-JUL-11 22:30:00 (MST-7)
Location: PHOENIX TURF ARPT
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Strong thunderstorms produced locally heavy rain across the greater Phoenix metropolitan area during the evening hours on July 31st. Rainfall rates in excess of one inch per hour led to street flooding in a number of areas, such as near I-17 and Thunderbird roads in central Phoenix, and near Queen Creek and Ellesworth roads in Queen Creek. Reports of heavy rain and street flooding were received from several trained spotters, and they led to the issuance of an urban and small stream flood advisory for the greater Phoenix area.

Thunderstorm Wind in PINAL, ARIZONA
From 31-JUL-11 19:40:00 to 31-JUL-11 19:40:00 (MST-7)
Location: SANTAN
Magnitude: 60.00 EG
Property damage: 50.00K
Crop damage: 0.00K
Reported by: Public

A trained weather spotter reported that there were numerous power poles downed just south of Gilbert Road and Hunt highway, about 5 miles east of Sun Lakes. The poles were downed by strong microburst winds estimated to be at least 60 knots. Strong microburst winds from these storms also blew over a nearby block wall approximately 10 feet long and 6 feet tall.