A backdoor cold front acted on a warm and moist air mass to produce severe thunderstorms. Wet microbursts and flash flooding were the results.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TWC wrote it up.
A backdoor cold front acted on a warm and moist air mass to produce severe thunderstorms. Wet microbursts and flash flooding were the results.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Tucson, AZ wrote its last area forecast discussion before the first event at Aug 24, 2:10 PM MST, 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 210 PM MST TUE AUG 24 2010 .SYNOPSIS...AMPLE MOISTURE AND A FAVORABLE FLOW WILL BRING SCATTERED SHOWERS AND THUNDERSTORMS TO SOUTHEAST ARIZONA THIS EVENING. A GRADUAL DECREASE IN SHOWERS AND THUNDERSTORMS IS EXPECTED WEDNESDAY INTO FRIDAY...FOLLOWED BY ANOTHER UPSWING IN THUNDERSTORM ACTIVITY BY EARLY NEXT WEEK. ABOVE NORMAL HIGH TEMPERATURES WILL CONTINUE THIS WEEK. && .DISCUSSION...A BACKDOOR COLD FRONT MANAGED TO PUSH FATHER WEST THAN PREVIOUSLY EXPECTED. THIS HAD RESULTED IN SHOWERS AND THUNDERSTORMS DEVELOPING OVER THE LOWER DESERTS FROM PINAL AND EASTERN PIMA WEST TO LA PAZ AND YUMA COUNTIES. BASED ON THIS...THE MAIN AREAS OF CONCERN FOR STRONG THUNDERSTORMS WITH DAMAGING WINDS AND LOCALLY HEAVY RAINFALL WILL BE ACROSS THE LOWER DESERTS OF SOUTHERN ARIZONA THROUGH AT LEAST 7 PM MST. SHOWERS AND THUNDERSTORMS ALONG THE EASTERN MOGOLLON RIM AND WHITES MOUNTAINS WERE MORE ORGANIZED ACROSS GILA COUNTY THIS AFTERNOON...WHICH WOULD FAVOR IMPACTING THE CENTRAL DESERTS/GREATER PHOENIX AREA/LATE THIS AFTERNOON AND EARLY THIS EVENING. STORMS DEVELOPING ACROSS OUR EASTERN CWA WILL REMAIN ISOLATED IN NATURE THIS AFTERNOON. THE ONLY CONCERN WILL BE ACROSS MAINLY COCHISE COUNTY WHERE A DISTURBANCE PASSING THROUGH THIS EVENING COULD TRIGGER MORE STORMS THERE. IF THIS HAPPENS...MIGHT SEE SOME SHOWERS AND THUNDERSTORMS MOVE INTO EASTERN PIMA AND PINAL COUNTIES LATE IN THE EVENING. OTHERWISE...SOMEWHAT LESS THUNDERSTORM ACTIVITY...EXCEPT FOR THE WESTERN DESERTS...WAS EXPECTED WEDNESDAY AND THURSDAY. THEREAFTER...AN INCREASE IN SHOWERS AND THUNDERSTORMS CAN BE ANTICIPATED FRIDAY AND SATURDAY AS A TROUGH OF LOW PRESSURE INTERACTS WITH MOISTURE OVER THE AREA. GFS MODEL WAS RATHER CONSISTENT IN ADVECTING DRIER AIR INTO MUCH OF ARIZONA SUNDAY INTO EARLY NEXT WEEK. THIS SHOULD RESULT IN A SIGNIFICANT DECREASE IN THUNDERSTORM ACTIVITY SUNDAY INTO WEDNESDAY OF NEXT WEEK. ABOVE NORMAL HIGH TEMPERATURES CAN BE EXPECTED THROUGH FRIDAY...THEN DAYTIME READINGS WILL TREND CLOSER TO NORMAL OR A FEW DEGS BELOW NORMAL BY EARLY NEXT WEEK. && .AVIATION...ISOLD-SCT TSRA/SHRA IN THE VALLEYS...AND SCT-NUMEROUS TSRA/SHRA IN THE MOUNTAINS THIS AFTERNOON/EVENING. OUTSIDE OF THE THUNDERSTORMS EXPECT SCT CLOUD BASES BETWEEN 5-7K FT AGL AND SCT-BKN CLOUD DECKS OF 10-12K FT AG...WITH ELY/SELY SURFACE WINDS AT 10-15 KTS AND SOME GUSTS TO AROUND 20 KTS. WITH THE STRONGER STORMS...MVFR CEILINGS/VSBYS EXPECTED AND WIND GUSTS TO NEAR 50 KTS. AFT 03Z WEDNESDAY...THE SHOWERS AND STORMS WILL DIMINISH...ALTHOUGH A SLIGHT CHANCE OF -TSRA/SHRA WILL PERSIST INTO WEDNESDAY MORNING. DIMINISHING CLOUDINESS IS EXPECTED AFT 06Z WEDNESDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. && .FIRE WEATHER...NO FIRE WEATHER CONCERNS AT THIS TIME. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. WEATHER.GOV/TUCSON
HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE TUCSON AZ 120 PM MST TUE AUG 24 2010 AZZ019-029>035-250600- NORTHERN GREENLEE COUNTY-SOUTHEAST PINAL COUNTY- UPPER GILA RIVER VALLEY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION- TUCSON METRO/MARANA/GREEN VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY- 120 PM MST TUE AUG 24 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL ARIZONA AND SOUTHEAST ARIZONA. .DAY ONE...THIS AFTERNOON AND TONIGHT THERE REMAINED AN INCREASED RISK OF STRONG THUNDERSTORMS WITH GUSTY WINDS IN EXCESS OF 60 MPH ALONG WITH LOCALLY HEAVY RAINFALL AND SMALL HAIL. THUNDERSTORMS THIS AFTERNOON HAVE DEVELOPED FARTHER WEST THAN PREVIOUSLY EXPECTED...WITH MOST OF THE ACTIVITY LOCATED ACROSS SOUTHEAST PINAL AND PIMA INTO WESTERN SANTA CRUZ COUNTIES AS OF 1 PM MST. BASED ON THE CURRENT LOCATION OF THE SHOWERS AND THUNDERSTORMS AND THE FACT THAT THE STEERING FLOW ALOFT REMAINED LIGHT...THUNDERSTORMS SHOULD BE FAVORED ACROSS THE LOWER DESERTS OF PIMA AND PINAL COUNTIES THE REMAINDER OF THIS AFTERNOON AND EARLY THIS EVENING. THUNDERSTORMS DEVELOPING ACROSS GREENLEE...GRAHAM...AND COCHISE COUNTIES SHOULD REMAIN MORE ISOLATED IN NATURE FOR MUCH OF THIS AFTERNOON. THUNDERSTORMS MAY INCREASE IN COVERAGE THIS EVENING ACROSS MAINLY COCHISE COUNTY AS A WEAK DISTURBANCE OVER MEXICO PASSES BY THE REGION. STORM MOVEMENT THIS AFTERNOON AND EVENING WILL BE TOWARD THE WEST AT LESS THAN 10 MPH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THERE WILL BE A CHANCE OF SHOWERS AND THUNDERSTORMS MAINLY IN AFTERNOON AND EVENING HOURS THROUGH THE MIDDLE OF THE WEEK. EXPECT GUSTY WINDS AND LOCALLY HEAVY RAINFALL WITH THE STRONGEST STORMS. THE PATTERN WILL THEN BECOME LESS FAVORABLE FOR SHOWER AND STORM DEVELOPMENT DURING THE LATTER HALF OF THE WEEK. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. WEATHER.GOV/TUCSON
The Phoenix radar (KIWA), 51 km away, was scanning. The volume nearest the first event began at 21:34 UTC.
6 thunderstorm wind, 4 flash flood, 3 lightning. Local standard time, as filed.
Thunderstorm winds downed tree limbs.
Lightning struck a palm tree at the Randolph Community Center. A fire was ignited, which spread to surrounding brush, prompting the evacuation of the center.
Thunderstorms developed over eastern portions of the Tucson area around 2:30 pm MST. Storms slowly moved to the east at around 5 to 10 mph dropping heavy rainfall and putting out thunderstorm winds in excess of 60 mph. The first reports of damage were received at 3 pm on the east side of Tucson. Several tree limbs were downed on Columbus Blvd, with a few power poles down on 6th street. At 3:09 pm, reports were received of several street signs down in the La Paloma Estates. By 3:15 pm, reports were coming in from the media about several roofs damaged in eastern sections of Tucson. Also around 3:15 pm, spotters reported several large trees downed in east Tucson, including trees down on 22nd St and Broadway Blvd. A large was blown into an election polling station building near S. Alvernon and E. Benson Highways in southern Tucson.
Thunderstorms produced heavy rain of up to 2 inches across portions of the Tucson metro area. Heavy rains resulted in a vehicle stalling in rising water at the intersection of Tucson Blvd. and Elm Street at 3:20 pm. By 4:00 pm, numerous streets were flooding near the University of Arizona campus in Tucson. Heavy rains falling near Ryan Field Airport resulted numerous washes flooding into residential neighborhoods. At 6:00 pm, firefighters pulled an 11 year old boy out of Alamo Wash near Tucson Medical Center.
Thunderstorms moving into Oracle resulted in trees and power lines downed across a roadway. The most extensive damage was a roof blown off of a home located on Bonito Drive in Oracle.
Severe thunderstorms redeveloped over central Tucson, moved westward and generated high winds causing a car port to collapse in midtown Tucson and a 63 mph wind gust to be recorded at Ryan Air Field.
The Benson News-Sun reported that a man was pulled from a running wash after he attempted to drive through 2 feet of running water on an adjacent street. The force of the water on the street carried his car into the wash and up against a concrete wall. The driver then attempted to get out of the vehicle, but fell 10-15 feet down into the wash underneath his car. Fire crews were able to quickly rescue the driver. He was escorted to the local hospital. City officials also reported numerous washes flooding neighborhood streets.
The Benson News-Sun and a local city official reported extensive damage to much of the city of Benson from thunderstorm activity. The city official reported numerous mature and young trees uprooted, street signs bent or pulled completely out of the ground, damage to dwellings from uprooted trees, small sheds and car ports were lifted and thrown 50-75 feet, and shingle damage to numerous homes. Also, property fences were knocked over, camper trailers were turned over, and numerous power outages. The newspaper added that one particular insurance provider received 40 claims from residents, mostly related to roof damage. Additional information from the newspaper stated that at least 80 street signs had to be replaced. Extensive damage was also done to the Turquoise Hills Golf Course where numerous large trees were downed and buildings damaged.
The Benson News-Sun reported several lightning strikes causing damage and fires in and around Benson. The most extensive lightning damage was done to two motors at the waste water treatment facility. Lightning also damaged numerous transformers.
Local Law Enforcement reported several trees and power lines down after thunderstorms moved through Whetstone.
Local law enforcement reported that Highway 191 between Safford and Interstate 10 had been closed due to flooding. At 7:00 pm, a spotter located in southern portions of Safford reported that he had received just over 3 inches of rainfall and that a majority of surrounding roads were impassable due to street flooding. According to Thatcher Police, a few homes near the Eastern Arizona College had water seep into their garages, one apartment suffered water damage, and the back room of a home on Fourth Avenue had water running into it. Also, a home south of Safford reported flood damage, and the Highway Department closed Safford/Bryce Road from Eighth Ave. to Bryce Eden Road due to flooding and debris. A vehicle also stalled in running water on Quattro Cerros Road near the Artesia area south of Safford. Water was running through the vehicle, but two passengers were able to get out. There were also several other reports of washed out roads and drainage problems.
After a majority of the thunderstorm activity had started to wind down, lightning struck a house in Oro Valley. The house then caught fire causing extensive damage.
Thunderstorms dropped heavy rain with amounts ranging from 1 inch up to 3.5 inches, causing numerous streets to flood in Sierra Vista. In addition, the Hereford Road Bridge at the San Pedro River was closed due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2010Every state in 2010This day in weather historyWarnings in Arizona, August 2010
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 244310, 244318, 246779, 246692, 247778, 257694, 247784, 247791, 247793, 247779, 246728, 247780, 246744.