Westward moving low pressure centered over Baja California helped to fuel storms over Southern Arizona. Severe thunderstorms impacted southern sections of the Tucson metro area causing thunderstorm wind damage and widespread flash flooding.
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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.
Westward moving low pressure centered over Baja California helped to fuel storms over Southern Arizona. Severe thunderstorms impacted southern sections of the Tucson metro area causing thunderstorm wind damage and widespread flash flooding.
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 Jul 20, 2:29 PM MST, 11 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 229 PM MST SAT JUL 20 2013 .SYNOPSIS...LOW PRESSURE OVER THE GULF OF CALIFORNIA WILL PROVIDE A MOIST EAST TO SOUTHEAST FLOW THIS WEEKEND. THIS FLOW WILL INCREASE CHANCES FOR SHOWERS AND THUNDERSTORMS WITH POTENTIALLY HEAVY RAINFALL. THEREAFTER...A MORE NORMAL CYCLE OF SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WILL RETURN FOR MUCH OF NEXT WEEK. && .DISCUSSION...THE UPPER LOW SPINNING OVER THE GULF OF CALIFORNIA WAS HELPING TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS EARLY THIS AFTERNOON. THE STEERING FLOW WAS TRACKING THIS ACTIVITY WESTWARD AT 15 MPH...WITH A FEW OF THE STRONGER THUNDERSTORMS PRODUCING RAINFALL AMOUNTS OF ONE-HALF OF INCH IN 15 TO 30 MINUTES. THAT SAID...THESE RAINFALL RATES CAN CAUSE MINOR FLOODING IN POOR DRAINAGE AREAS AND RAPID RUNOFF INTO NORMALLY DRY WASHES. THE STRONGEST STORMS COULD PRODUCE HIGH WINDS...BUT FLASH FLOODING WILL BE THE PRIMARY THREAT FROM THESE STORMS TODAY. THE UPPER LOW OVER THE GULF OF CALIFORNIA TODAY WILL TRACK THROUGH SOUTHERN CALIFORNIA AND WEAKEN SUNDAY INTO MONDAY. WILL SEE ANOTHER ACTIVE THUNDERSTORM DAY TOMORROW BEFORE DRIER AIR SPREADS IN BEHIND THE UPPER LOW ON MONDAY. THEREAFTER...HIGH PRESSURE ALOFT BECOMES CENTERED NEAR THE FOUR CORNERS REGION AROUND TUESDAY AND WEDNESDAY. OVERALL...THE PATTERN APPEARED FAVORABLE FOR DAILY THUNDERSTORM ACTIVITY THROUGH AT LEAST FRIDAY. && .AVIATION...SCATTERED TO NUMEROUS SHRA/TSRA WILL CONTINUE INTO THE EVENING...BECOMING MORE ISOLATED AFT 21/03Z. EXPECT MVFR CIGS AND VSBYS WITH BRIEF WIND GUSTS UP TO 40 KTS WITH THE STRONGER TSRA. CONDITIONS SCT-BKN060 SCT-BKN100 BKN250 THEN AFT 21/08Z SCT060 SCT-BKN100. SURFACE WIND DIURNAL IN DIRECTION AND GENERALLY LESS THAN 10 KTS THRU SUNDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS. CERNIGLIA && .FIRE WEATHER...AN UPPER LOW OVER THE NORTHERN GULF OF CALIFORNIA WILL CONTINUE TO PUMP MOISTURE OVER SOUTHERN ARIZONA THROUGH SUNDAY AS IT SLOWLY MOVES WEST. THIS MOISTURE AND THE RESULTANT INSTABILITY WILL BRING ABOUT PLENTY OF CONVECTION THROUGH SUNDAY EVENING. THE STRONGER THUNDERSTORMS WILL BE CAPABLE OF PRODUCING HEAVY DOWNPOURS DUE TO THE ABUNDANT MOISTURE AS WELL AS GUSTY AND ERRATIC WINDS. NORMAL DIURNAL WIND PATTERNS ARE EXPECTED OVER THE NEXT SEVERAL DAYS...HOWEVER THEY WILL BE DISRUPTED AT TIMES DUE TO STORM OUTFLOWS. THE SHOWERS AND THUNDERSTORMS WILL BECOME LESS NUMEROUS AND MORE LIMITED TO THE AFTERNOON AND EVENING HOURS MONDAY AND TUESDAY AS THE LOW MOVES FURTHER WEST AND THE AIR MASS BECOMES A BIT DRIER OVER THE REGION. ANOTHER EASTERLY WAVE WILL ENHANCE THE CONVECTION ACROSS SOUTHERN ARIZONA WEDNESDAY AND THURSDAY AS IT PASSES BY TO THE SOUTH. CERNIGLIA && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE TUCSON AZ 208 PM MST SAT JUL 20 2013 AZZ503-504-507-513-514-202200- DRAGOON/MULE/HUACHUCA AND SANTA RITA MOUNTAINS INCLUDING BISBEE/CANELO HILLS/MADERA CANYON AZ-SANTA CATALINA AND RINCON MOUNTAINS INCLUDING MOUNT LEMMON/SUMMERHAVEN AZ-TUCSON METRO AREA INCLUDING TUCSON/GREEN VALLEY/MARANA/VAIL AZ-UPPER SAN PEDRO RIVER VALLEY INCLUDING SIERRA VISTA/BENSON AZ-UPPER SANTA CRUZ RIVER AND ALTAR VALLEYS INCLUDING NOGALES AZ- 208 PM MST SAT JUL 20 2013 ...SIGNIFICANT WEATHER ADVISORY FOR EASTERN PIMA COUNTY UNTIL 300 PM MST... AT 200 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 5 MILES EAST OF GREEN VALLEY...MOVING WEST AT 15 MPH AND ANOTHER IN NEAR VAIL...MOVING WEST AT 15 MPH. WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS...ALONG WITH HEAVY RAIN. AREAS AFFECTED BY THIS STORM INCLUDE...GREEN VALLEY...SAHUARITA... TUCSON INTERNATIONAL AIRPORT...SOUTH TUCSON AND SAN XAVIER MISSION. LAT...LON 3175 11120 3223 11102 3219 11052 3175 11054 TIME...MOT...LOC 2108Z 097DEG 13KT 3183 11096 GL
The Tucson radar (KEMX), 36 km away, was scanning. The volume nearest the first event began at 21:37 UTC.
2 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Thunderstorm winds downed a tree near 29th Street and Houghton Road and downed power lines at Irvington and Houghton Roads.
Heavy rain of around one inch in less than 30 minutes caused flash flooding across portions of the Tucson metro area. Tucson’s southeast side was hit hard along Houghton Road from Sahuarita Road north to Golf Links Road then west to around Wilmot Road. Motorists became stranded in vehicles and several people were trapped in washes when the normally dry stream beds began to flow rapidly. One person was injured after being washed downstream in Rose Hill Wash on Tucson’s east side. Other swift water rescues occurred in the Pantano Wash near Golf Links Road and the Rillito River near La Canada Drive. In addition, a motorist was rescued from his vehicle near Creek Street and Bonanza Avenue. The vehicle was later swept away. Near the Tucson International Airport, six inches of pavement depth along a section of South Sears Boulevard near the was completely washed away. Tucson’s southwest side also received heavy rain totaling 1 to 2 inches, especially along Valencia Road from Campbell Avenue westward to near Ryan Field. Several cars were stranded along San Joaquin Road and sections of Snyder Hill Road and Old Ajo Highway were closed due to flash flooding.
Thunderstorm winds downed a large tree near Congress St. and Scott Avenue.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2013Every state in 2013This day in weather historyWarnings in Arizona, July 2013
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: 459775, 460084, 459778.