Plenty of moisture and a low pushing through Southern California helped to develop a wide-spread outbreak of heavy showers and thunderstorms developed across Southeast Arizona. 6 inches.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
Plenty of moisture and a low pushing through Southern California helped to develop a wide-spread outbreak of heavy showers and thunderstorms developed across Southeast Arizona. Precipitable water values ranged from 1.4 to 1.6 inches. A large complex developed over Southeastern Arizona by early afternoon and continued into the early evening hours. There were many reports of flooding, hail and strong winds throughout Southeast Arizona.
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 13, 2:30 PM MST, 2 hours earlier.
AREA FORECAST DISCUSSION...CORRECTION NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST FRI AUG 13 2004 CORRECTED TO INCLUDE MENTION OF FLASH FLOOD WATCH SOUTHEAST ARIZONA FORECAST DISCUSSION .SYNOPSIS...A SERIES OF UPPER LEVEL DISTURBANCES BROUGHT AN INCREASE IN THUNDERSTORM ACTIVITY TODAY AND IS EXPECTED TO DO SO AGAIN SATURDAY. BY EARLY NEXT WEEK...DRIER CONDITIONS ARE EXPECTED AS THE UPPER HIGH BREAKS DOWN INTO MEXICO. HOWEVER...THERE SHOULD BE SOME LINGERING MOISTURE FOR ISOLATED THUNDERSTORMS OVER MAINLY HIGHER TERRAIN. && .DISCUSSION...SPECIAL 18Z SOUNDING SHOWED PLENTY WET AND UNSTABLE. COMBINED WITH THE APPROACHING INFLUENCE OF THE LOW PUSHING THROUGH SOUTHERN CALIFORNIA...WE ISSUED A FLASH FLOOD WATCH FOR ALL OF SOUTHEAST ARIZONA. HEAVY COVERAGE WITH STRONG TO NEAR SEVERE STORMS...BUT THE MAIN DEAL HAS BEEN HOW WET THEY ARE. POTENTIAL TO KEEP FIRING WELL INTO THE EVENING HOURS AND OVERNIGHT WITH DYNAMICS MOVING IN AND BOUNCING / INTERSECTING BOUNDARIES. ANOTHER FAVORABLE DAY SATURDAY AS LONG AS WE DONT GET TOO WORKED OVER IN THE NEXT 12 HOURS. SUNDAY COULD BE PRETTY GOOD TOO BEFORE THE RIDGE LOOSES MUCH OF ITS GEOMETRY AND THE HIGH CENTER RECONSOLIDATES TO OUR SOUTH. ENOUGH MOISTURE TO RECIRCULATE FOR A COUPLE OF DAYS...BUT TOO LONG AND OUR MAIN FLOW OF MOISTURE WOULD TEND TO BE BLOCKED IN THIS SCENARIO. && .TWC WATCHES/WARNINGS/ADVISORIES...FLASH FLOOD WATCH FOR ALL OF SOUTHEAST ARIZONA (ZNS 019-029>035) UNTIL 9 PM MST. MEYER
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1220 PM MST FRI AUG 13 2004 AZZ019-029>035-140700- NORTHERN GREENLEE COUNTY-UPPER GILA RIVER VALLEY-COCHISE COUNTY- SOUTHEAST PINAL COUNTY-TUCSON METRO/MARANA/GREEN VALLEY- SANTA CRUZ COUNTY-TOHONO OODHAM NATION-WESTERN PIMA COUNTY- 1220 PM MST FRI AUG 13 2004 ...FLASH FLOOD WATCH EFFECTIVE FOR ALL OF SOUTHEAST ARIZONA EFFECTIVE UNTIL 9 PM MST... THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA .DAY ONE...TODAY SYNOPSIS...THE COMBINATION OF MOISTURE AND UPPER LEVEL FORCING WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS TODAY...WITH THE MAIN THREAT OF HEAVY RAINFALL. A FEW OF THESE THUNDERSTORMS MAY PRODUCE DAMAGING WINDS AND HAIL. DISCUSSION...INCREASE IN MOISTURE ACROSS SOUTHERN ARIZONA WITH GOES TOTAL PW VALUES RANGING FROM 1.4 TO 1.6 INCHES. BOTH THE 12Z AND 18Z SOUNDING WAS SIMILAR WITH PW OF 1.4 INCHES. ALSO RATHER MOIST IN LOWER LEVELS WITH SURFACE DEW POINT TEMPERATURES OF 60S TO WEST WITH LOWER 50S IN EASTERN PORTIONS OF CWA. LATEST SOUNDING KTUS SHOWED SLIGHT INCREASE IN 700MB WINDS...BUT STILL RATHER WEAK FLOW. THE INCREASED MOISTURE ACROSS THE AREA COMBINED WITH DECENT UPPER LEVEL FORCING FROM THE UPPER LEVEL LOW MOVING INTO CALIFORNIA WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS. ALREADY THE KEMX RADAR SHOWS THUNDERSTORM DEVELOPMENT ACROSS THE HIGHER TERRAIN. ALTHOUGH STORMS WILL INITIALLY REMAIN OVER MOUNTAINS...THEY SHOULD BE ABLE TO MOVE INTO THE VALLEY LATER THIS AFTERNOON. STORM MOTION WILL BE SLOW (NORTH TO NORTHEAST AT 5 MPH) AND THE MAIN THREAT FOR HEAVY PRECIPITATION IS EXPECTED AT TRAINING WILL LIKELY OCCUR. RAINFALL RATES AREA EXPECTED TO RANGE AROUND AN INCH AN HOUR...WITH HEAVIER RAINFALL RATES OVER THE HIGHER TERRAIN. THUS HAVE DECIDED TO ISSUE A FLASH FLOOD WATCH FOR THE ENTIRE CWA UNTIL 9 PM MST. ALTHOUGH THUNDERSTORM ACTIVITY IS EXPECTED TO CONTINUE THROUGH THE NIGHT...WILL ALLOW THE EVENING SHIFT BE ABLE TO RE-EVALUATE THE SITUATION AND IF NECESSARY EXTEND THE FLASH FLOOD WATCH. ALTHOUGH THE MAIN THREAT WILL BE HEAVY PRECIPITATION...A FEW OF THESE THUNDERSTORMS MAY PRODUCE DAMAGING WINDS IN EXCESS OF 58 MPH AND HAIL. EARLIER IN THE AFTERNOON THERE MAY BE BLOWING DUST...PARTICULARLY ALONG DUST PRONE AREAS SUCH AS INTERSTATE 10 BETWEEN TUCSON AND PHOENIX AND BETWEEN BENSON AND SAN SIMON. OUTFLOW FROM THUNDERSTORMS WILL PRODUCE BLOWING DUST AND MAY REDUCE VISIBILITIES. IN GENERAL...MOTORISTS SHOULD USE CAUTION TODAY. DO NOT DRIVE INTO FLOODED AREAS. SMALL STREAMS...SECONDARY ROADS...AND NORMALLY DRY WASHES WILL FLOOD QUICKLY. MOVE TO HIGHER GROUND. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY. SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO OCCUR SATURDAY. THE POTENTIAL OF LOCALLY HEAVY RAINS WILL PARTICULARLY EXIST SATURDAY AFTERNOON AND EVENING. A GRADUAL DRYING TREND IS EXPECTED STARTING SUNDAY AND WILL CONTINUE THROUGH THE MIDDLE OF NEXT WEEK. ANY THUNDERSTORMS OF SIGNIFICANCE BY WEDNESDAY WILL BE CONFINED TO JUST NEAR THE MOUNTAINS OF FAR SOUTHEAST ARIZONA. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MG
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
1240 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
1239 PM HAIL 2 W GREEN VALLEY 31.85N 111.04W
08/13/2004 0.75 INCH PIMA AZ TRAINED SPOTTER
&&
PYTLAKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
1252 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
1251 PM HAIL 5 NW GREEN VALLEY 31.90N 111.07W
08/13/2004 1.00 INCH PIMA AZ TRAINED SPOTTER
&&
PYTLAKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
211 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0130 PM FLASH FLOOD 5 N GREEN VALLEY 31.92N 111.01W
08/13/2004 PIMA AZ LAW ENFORCEMENT
SEVERAL STREETS FLOODED IN SAHUARITA. SAHUARITA RD.
TEMPORARILY BLOCKED BY HIGH WATER.
0130 PM LIGHTNING 5 N GREEN VALLEY 31.92N 111.01W
08/13/2004 PIMA AZ LAW ENFORCEMENT
LIGHTNING STRIKE TO SAHUARITA HIGH SCHOOL.
&&
PYTLAKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
233 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0232 PM FLASH FLOOD RIO RICO 31.48N 110.98W
08/13/2004 SANTA CRUZ AZ COUNTY OFFICIAL
PENDELTON DRIVE BLOCKED BY 1.5 FOOT OF WATER. FLOOD
WATERS STILL RISING RAPIDLY.
&&
PYTLAKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
353 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0352 PM TSTM WND DMG 5 NE ORACLE 32.67N 110.72W
08/13/2004 PINAL AZ LAW ENFORCEMENT
10 TO 15 POWER POLES DOWN ALONG HIGHWAY 77 NEAR MILE POST
115.
&&
PYTLAKPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TUCSON AZ
403 PM MST FRI AUG 13 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0330 PM TSTM WND DMG MAMMOTH 32.72N 110.64W
08/13/2004 PINAL AZ LAW ENFORCEMENT
POWER LINES DOWN.
&&
PYTLAKThe Tucson radar (KEMX), 112 km away, was scanning. The volume nearest the first event began at 23:29 UTC.
1 flash flood. Local standard time, as filed.
There were several street closures due to flooding near Avra Valley Road, also near Rattlesnake pass between Silverbell Road and Twin Peaks Road. The intersection of Tangerine Road and Thornydale Road was impassable due to high running water.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2004Every state in 2004This day in weather historyWarnings in Arizona, August 2004
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: 5419937.