An outflow from a large complex that developed in Northern Mexico pushed moisture north into southeastern Arizona. This moisture helped to promote the development of heavy raining thunderstorms across the area.
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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.
An outflow from a large complex that developed in Northern Mexico pushed moisture north into southeastern Arizona. This moisture helped to promote the development of heavy raining thunderstorms across the area.
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 24, 9:47 PM MST, 1 hour 13 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 947 PM MST SAT JUL 24 2004 SOUTHEAST ARIZONA FORECAST DISCUSSION .SYNOPSIS...A MOIST AND UNSTABLE AIRMASS WILL PROVIDE SCATTERED THUNDERSTORMS THIS WEEKEND. UPPER LEVEL HIGH PRESSURE IS FORECAST TO MOVE WESTWARD BY THE MIDDLE OF NEXT WEEK...RESULTING IN A DECREASE IN THUNDERSTORM ACTIVITY. && .DISCUSSION...A RATHER QUIET NIGHT ACROSS SOUTHEAST ARIZONA AS NO SEVERE THUNDERSTORM OR FLASH FLOOD WARNINGS WERE ISSUED THIS EVENING. THERE WERE...HOWEVER...A FEW STRONG STORMS THAT PUSHED THROUGH SOUTHEAST PINAL COUNTY EARLIER THIS EVENING. THESE STORMS WERE MAINLY GENERATED AHEAD OF A COUPLE OF STRONG OUTFLOW BOUNDARIES FROM STORMS IN NORTHERN PINAL AND EASTERN GILA COUNTIES LATE THIS AFTERNOON. AS OF 930 PM...KIWA 0.5 DEG VELOCITY IMAGERY INDICATED THE MAIN OUTFLOW BOUNDARY WAS STILL ALIVE AND KICKING...AND WAS PUSHING INTO SOUTHERN MARICOPA AND NORTH CENTRAL PIMA COUNTIES... HELPING TO TRIGGER SCATTERED SHOWERS AND THUNDERSTORMS IN THOSE LOCATIONS. UPDATED ZFP AND PFM FORECAST TO DECREASE POPS IN THE EAST AND BUMP THEM UP A TAD IN THE WESTERN DESERTS. OTHERWISE...STRANGE PATTERN FOR JULY AS UPPER HIGH CENTER MOVES OFF THE COAST OF CALIFORNIA THE NEXT COUPLE OF DAYS IN RESPONSE TO A TROUGH MOVING INTO THE GREAT BASIN FROM THE NORTHWEST. PLENTY OF MOISTURE AVAILABLE TOMORROW WITH NORTH TO NORTHEAST STEERING FLOW...MAY SEE ANOTHER AFTERNOON/EVENING OF STORMS MOVING OFF OF THE RIM. WILL ALSO HAVE TO BE AWARE OF HOW THE WEAK BACKDOOR SURFACE FRONT AFFECTS THINGS OUT EAST TOMORROW AS WELL. A DECREASE IN POPS ARE IN STORE THE SECOND HALF OF THE WORK WEEK AS THE UPPER HIGH THEN BECOMES ESTABLISHED SOUTH OF THIS FORECAST AREA ACROSS BAJA AND/OR SONORA. && .TWC WATCHES/WARNINGS/ADVISORIES...NONE.
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1215 PM MST SAT JUL 24 2004 AZZ019-029>035-250700- 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- 1215 PM MST FRI JUL 24 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA .DAY ONE...TODAY SYNOPSIS...THE POTENTIAL FOR HEAVY RAINFALL IS ABOVE NORMAL ACROSS SOUTHEAST ARIZONA TODAY. THE POTENTIAL FOR STRONG DOWNBURST WINDS IS NEAR NORMAL TODAY. DAYTIME HEATING IN COMBINATION WITH ABUNDANT MOISTURE AND AN UNSTABLE ENVIRONMENT WILL PROVIDE ALL OF SOUTHEAST ARIZONA WITH AT LEAST A CHANCE OF THUNDERSTORMS. DISCUSSION...THE UPPER AIR SOUNDING AT TUCSON THIS MORNING DEPICTED A PRECIPITABLE WATER VALUE NEAR 1.45 INCHES AND THUS WAS NOT QUITE AS MOIST AS 24 HOURS AGO. THE PROFILE WAS NOT QUITE AS UNSTABLE AS 24 HOURS AGO AS WELL AS EVIDENCED VIA LIFTED INDEX VALUE NEAR MINUS 2 AND UNMODIFIED SURFACE-BASED CAPE VALUE NEAR 635 J/KG. HOWEVER THE MID-LEVEL WIND COMPONENT OF 25-30 KTS FROM THE NORTHEAST WAS SOMEWHAT STRONGER VERSUS FRIDAY MORNING. THE UPPER HIGH WAS CENTERED NEAR FLAGSTAFF THIS MORNING PROVIDING AN EAST TO NORTHEAST FLOW OVER SOUTHEAST ARIZONA. SOMEWHAT DIFFICULT TO DETERMINE WHERE CONVECTIVE INITIATION WILL THIS AFTERNOON GIVEN THE EXTENSIVE CLOUDINESS ACROSS EASTERN SECTIONS AT THIS TIME. DEEP CONVECTION MAY INITIATE ALONG THE INTERFACE OF THE CLOUD SHIELD AT THIS TIME ACROSS THE EAST AND THE CLEAR REGION OVER THE WEST. THE MAIN CONCERN WILL BE WITH REGARD TO LOCALLY HEAVY RAINFALL AS THE AIRMASS REMAINS QUITE MOIST. RAINFALL AMOUNTS OF 1 TO 1.5 INCHES WILL BE POSSIBLE IN THE STRONGEST STORMS. SHOWERS AND THUNDERSTORMS THAT DEVELOP THIS AFTERNOON ALONG THE MOGOLLON RIM WILL MOVE TO THE SOUTHWEST LATER THIS AFTERNOON AND EVENING. SOME OF THESE STORMS HOLD THE POTENTIAL FOR WIND GUSTS TO NEAR 55 MPH ALONG WITH SMALL HAIL...AND MAY IMPACT THE TUCSON AREA AROUND SUNSET OR SHORTLY THEREAFTER. THE BULK OF ANY PRECIPITATION THAT DEVELOPS SHOULD DECREASE IN COVERAGE AND INTENSITY BY MIDNIGHT THOUGH SOME SHOWERS WILL LIKELY CONTINUE AFTER MIDNIGHT. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH SATURDAY. ANOTHER ACTIVE DAY IS EXPECTED ON SUNDAY AS THE UPPER HIGH REMAINS OVER NORTHERN ARIZONA. A MORE TYPICAL MONSOON PATTERN IS EXPECTED MONDAY AND TUESDAY. THE UPPER HIGH IS FORECAST TO A POSITION OVER NORTHERN BAJA BY WEDNESDAY AS A STRONG TROUGH OF LOWER PRESSURE MOVES ACROSS THE NORTHERN ROCKIES. THIS PATTERN WILL LEAD TO DECREASED THUNDERSTORM CHANCES ACROSS SOUTHEAST ARIZONA THURSDAY THROUGH SATURDAY. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. BF
The national radar mosaic for the moment the first event began.
1 thunderstorm wind. Local standard time, as filed.
Law enforcement reported that thunderstorm wind gusts up to 55 knots had downed 5 power poles on Route 85 between mile marker 45 and 47.
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, July 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: 5415720.