Strong thunderstorms produced heavy rainfall over the higher terrain of the Catalina Mountains. This heavy rainfall produced a flash flood which moved downstream into Bear Canyon and the popular Seven Falls area causing two fatalities.
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.
Strong thunderstorms produced heavy rainfall over the higher terrain of the Catalina Mountains. This heavy rainfall produced a flash flood which moved downstream into Bear Canyon and the popular Seven Falls area causing two fatalities. Flash flooding also occurred in the Whetstone area of Cochise County.
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 4, 9:20 AM MST, 4 hours 40 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 920 AM MST SAT AUG 4 2007 .SYNOPSIS...A LOW PRESSURE CENTER OVER NORTHERN MEXICO WILL AFFECT SOUTHEAST ARIZONA THROUGH SUNDAY WITH THUNDERSTORMS...SOME OF WHICH WILL PRODUCE HEAVY RAIN. THIS DISTURBANCE WILL TURN NORTH INTO SOUTHERN ARIZONA BY LATE MONDAY AS A TROUGH OF LOW PRESSURE DEVELOPS ALONG THE WEST COAST AND MOVES INLAND. SOUTHWEST FLOW AHEAD OF THE TROUGH IS EXPECTED TO TEMPORARILY PUSH THE DEEPER MOISTURE OUT OF THE AREA AND RESULT IN A DECREASE IN THUNDERSTORMS BY THE MIDDLE OF NEXT WEEK. && .DISCUSSION...DEBRIS CLOUDINESS HANGING TOUGH ACROSS PINAL/PIMA AND SANTA CRUZ COUNTIES THIS MORNING WITH SOME SUNSHINE BREAKING OUT IN GRAHAM/COCHISE AND GREENLEE COUNTIES. REGIONAL RADARS...AS OF 9 AM...DEPICTED SOME LIGHT SHOWERS JUST SOUTHWEST OF METRO PHOENIX WITH A FEW CELLS JUST WEST OF TUCSON. UPPER AIR PLOTS AND WATER VAPOR IMAGERY SHOWED A WEAK INVERTED TROUGH IN NORTHERN MEXICO ALONG THE SONORA/CHIHUAHUA STATE LINE AND EXTENDING NORTH ALONG AZ/NM STATE LINE. THIS FEATURE WAS MOVING SLOWLY TO THE WEST. SOUPY ATMOSPHERE IN PLACE ACROSS SOUTHEAST ARIZONA WITH TUCSON SOUNDING SHOWING PW VALUE JUST UNDER 2. THIS HIGH PW VALUE ALONG WITH LIGHT STEERING FLOW WILL RESULT IN SLOW MOVING DUMPERS. THE SOUNDING ALSO SHOWED THAT THE MID-LAYERS HAVE COOLED A COUPLE DEGREES CELSIUS WITH 500 MB TEMP AROUND -4C VERSUS -2C FRIDAY. HOWEVER...THE 12Z MODEL WANT TO PUSH THIS COOL POOL WEST AND BRING IN -3C AIR...SEEN ON EL PASO MORNING SOUNDING...ACROSS SOUTHEAST ARIZONA. THE INHIBITING FACTOR WILL BE HOW LONG WILL IT TAKE TO BURN OFF OF THE DEBRIS CLOUDINESS....ESPECIALLY ACROSS PINAL/E PIMA/SANTA CRUZ COUNTIES. I BELIEVE THAT THERE WILL BE MORE AREAL COVERAGE VERSUS YESTERDAY WITH THE MAIN THREAT OF FLASH FLOODING RESIDING IN GRAHAM/COCHISE COUNTIES WHERE THEY WILL SEE MORE SUN AND AREAL COVERAGE SHOULD BE THE MORE THAN THE REST OF THE FORECAST AREA. I BRIEFLY CONSIDERED A FLASH FLOOD WATCH FOR AREA EAST OF TUCSON...BUT WILL WAIT TO SEE HOW THINGS DEVELOP THIS AFTERNOON. && .AVIATION...SCATTERED THUNDERSTORMS PRIMARILY DURING THE AFTERNOON AND EVENING HOURS THROUGH THE WEEKEND. THESE THUNDERSTORMS WILL PRODUCE HEAVY PRECIPITATION WHICH IN TURN COULD DROP CEILINGS AND VISIBILITIES INTO THE IFR CATEGORY IF OVER AN AIRPORT. AVIATION DISCUSSION NOT UPDATED FOR TAF AND TWEB AMENDMENTS. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE. && DISCUSSION...JRG AVIATION...GWS WEATHER.GOV/TUCSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 615 AM MST SAT AUG 4 2007 AZZ019-030-033>035-051400- NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY- TUCSON METRO/MARANA/GREEN VALLEY-SANTA CRUZ COUNTY-COCHISE COUNTY- 615 AM MST SAT AUG 4 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST ARIZONA. .DAY ONE...TODAY AND TONIGHT. AN UPPER LEVEL DISTURBANCE MOVING WESTWARD ACROSS MEXICO IS HELPING TO TRIGGER SHOWERS ACROSS NORTHERN SONORA AND SOUTHEAST ARIZONA. THE SHOWERS WILL INCREASE IN COVERAGE AS THE DAY PROGRESSES WITH SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY DURING THE AFTERNOON AND EVENING HOURS. THIS MORNINGS UPPER AIR SOUNDING INDICATED A VERY MOIST AND UNSTABLE AIRMASS IN PLACE. THE WINDS ALOFT...ESPECIALLY THE WINDS THAT WILL STEER THE STORMS ARE RATHER LIGHT...SO STORM MOTIONS TODAY WILL BE GENERALLY TO THE SOUTHWEST OR WEST AT LESS THAN 10 MPH. AS A RESULT...EXPECT THE PRIMARY CONCERN WITH THE STORMS THAT DEVELOP TODAY TO BE FLOODING ISSUES. HOWEVER...STRONG GUSTY DOWNBURSTS WINDS MAY ALSO ACCOMPANY THE STORMS AS WELL. A FEW OF THE STORMS THAT DEVELOP TODAY MAY APPROACH OR PERHAPS EVEN EXCEED SEVERE LEVELS...BUT ORGANIZED SEVERE WEATHER IS NOT EXPECTED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. THE UPPER LOW OVER MEXICO WILL MOVE INTO THE GULF OF CALIFORNIA THIS WEEKEND WITH THE SYSTEM MOVING NORTHWARD INTO ARIZONA ON MONDAY. THIS IS IN RESPONSE TO A PACIFIC TROUGH MOVING TOWARD THE WEST COAST. AS THE LOW MOVES OVER ARIZONA ON MONDAY...FAVORABLE DYNAMICS ALONG WITH PLENTY OF MOISTURE STILL IN PLACE COULD RESULT IN A FEW SEVERE STORMS. BEYOND MONDAY DRIER AIR WILL BEGIN TO FILTER IN FROM THE WEST WHICH WILL RESULT IN LOWER RAIN CHANCES THROUGH THE END OF THE WEEK. THE BEST CHANCES FOR RAIN THROUGH THE END OF THE WEEK WILL BE MAINLY ALONG THE ARIZONA AND NEW MEXICO BORDER. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. AZZ029-031-032-051400- SOUTHEAST PINAL COUNTY-WESTERN PIMA COUNTY-TOHONO OODHAM NATION- 615 AM MST SAT AUG 4 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL ARIZONA. .DAY ONE...TODAY AND TONIGHT. AN UPPER LEVEL DISTURBANCE MOVING WESTWARD ACROSS MEXICO IS HELPING TO TRIGGER SHOWERS ACROSS NORTHERN SONORA AND SOUTHEAST ARIZONA. THE SHOWERS WILL INCREASE IN COVERAGE AS THE DAY PROGRESSES WITH ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING MAINLY DURING THE AFTERNOON AND EVENING HOURS. THIS MORNINGS UPPER AIR SOUNDING INDICATED A VERY MOIST AND UNSTABLE AIRMASS IN PLACE. THE WINDS ALOFT...ESPECIALLY THE WINDS THAT WILL STEER THE STORMS ARE RATHER LIGHT...SO STORM MOTIONS TODAY WILL BE GENERALLY TO THE SOUTHWEST OR WEST AT LESS THAN 10 MPH. AS A RESULT...EXPECT THE PRIMARY CONCERN WITH THE STORMS THAT DEVELOP TODAY TO BE FLOODING ISSUES. HOWEVER...STRONG GUSTY DOWNBURSTS WINDS MAY ALSO ACCOMPANY THE STORMS AS WELL. A FEW OF THE STORMS THAT DEVELOP TODAY MAY APPROACH OR PERHAPS EVEN EXCEED SEVERE LEVELS...BUT ORGANIZED SEVERE WEATHER IS NOT EXPECTED. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY. THE UPPER LOW OVER MEXICO WILL MOVE INTO THE GULF OF CALIFORNIA THIS WEEKEND WITH THE SYSTEM MOVING NORTHWARD INTO ARIZONA ON MONDAY. THIS IS IN RESPONSE TO A PACIFIC TROUGH MOVING TOWARD THE WEST COAST. AS THE LOW MOVES OVER ARIZONA ON MONDAY...FAVORABLE DYNAMICS ALONG WITH PLENTY OF MOISTURE STILL IN PLACE COULD RESULT IN A FEW SEVERE STORMS. BEYOND MONDAY DRIER AIR WILL BEGIN TO FILTER IN FROM THE WEST WHICH WILL RESULT IN LOWER RAIN CHANCES THROUGH THE END OF THE WEEK. THE BEST CHANCES FOR RAIN THROUGH THE END OF THE WEEK WILL BE MAINLY ALONG THE ARIZONA AND NEW MEXICO BORDER. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Tucson radar (KEMX), 53 km away, was scanning. The volume nearest the first event began at 21:01 UTC.
2 flash flood. Local standard time, as filed.
Large wall of water moved down seven falls in Bear Canyon. About 50 people sought higher ground and many of those needed to be rescued by helicopter.
Flash flooding occurred in Whetstone at an RV dealership mainly impacting the maintenance bays.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flash Flood, Pima | 2007-08-04 | 19 | Female | Outside/Open Areas | Direct |
| Flash Flood, Pima | 2007-08-04 | 25 | Male | Outside/Open Areas | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2007Every state in 2007This day in weather historyWarnings in Arizona, August 2007
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: 51108, 54291.