Name: Flash Flood in Arizona, August 2, 2002
Start: 2002-08-02T15:30
End: 2002-08-02T17:00
Location: Arizona

Where it happened

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.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: $5,000
Crop damage: None recorded
Events: 1

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.

What happened

The episode as NWS TWC wrote it up.

Another round of thunderstorms produced heavy rainfall over the town of Arivaca. A spotter reported 3 inches of rain, with water flooding into his house at 410 pm MST. An automated gauge in the area recorded 2.09 inches of rainfall between 330 pm and 430 pm MST.

What forecasters said that day

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 2, 2:18 PM MST, 1 hour 12 minutes earlier.

Area forecast discussion, Aug 2, 2:18 PM MST, 1 hour 12 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
218 PM MST FRI AUG 2 2002

.SYNOPSIS...HIGH PRESSURE CENTERED OVER THE CENTRAL UNITED STATES
WILL PROVIDE A MOIST SOUTHERLY FLOW FOR A CONTINUED CHANCE OF MAINLY
AFTERNOON AND EVENING THUNDERSTORMS. A TROUGH OF LOW PRESSURE WILL
DEVELOP ALONG THE WEST COAST SUNDAY...BRINGING A DRIER SOUTHWESTERLY
FLOW TO WESTERN SECTIONS. THIS DRY AIR WILL TEND TO LIMIT
THUNDERSTORMS TO THE FAR SOUTHEAST THROUGH MID NEXT WEEK.

.DISCUSSION...A WEAK SHORTWAVE TROUGH CONTINUED TO LIFT NORTH OF THE
STATE THIS AFTERNOON. SHOWERS AND THUNDERSTORMS HAVE BEEN CONFINED
MAINLY IN SOUTHERN PIMA AND SANTA CRUZ COUNTIES SO FAR. LOOKS LIKE
THE STORM MOTION WILL BE VERY LITTLE WITH A TENDENCY TO DRIFT
SOUTHWEST. MAIN THREAT FROM THESE STORMS WILL BE HEAVY RAINFALL.
WILL NEED TO WATCH FOR ACTIVITY ACROSS COCHISE COUNTY THIS EVENING
DUE TO THE 1 TO TWO INCH AMOUNTS OF RAIN THAT FELL YESTERDAY OVER A
FAIRLY LARGE AREA. SOME OF THE SMALL STREAMS AND RIVERS WERE
RESPONDING TO THE RUNOFF TODAY...SEE PHXRVSTWC FOR MORE DETAILS.
HIGH PRESSURE CENTERED OVER THE CENTRAL UNITED STATES WILL SHIFT
FARTHER EAST THIS WEEK AS A TROUGH OF LOW PRESSURE DEVELOPS ALONG
THE WEST COAST. THIS WILL GIVE EASTERN ARIZONA MORE OF A SOUTHEAST
TO EASTERLY FLOW WITH TIME...BUT A DRIER SOUTHWESTERLY FLOW WILL
DOMINATE THE WESTERN ONE-THIRD OF THE STATE. THUS...WILL CALL FOR
THE SAME IN TERMS OF THUNDERSTORM ACTIVITY ACROSS OUR EASTERN ZONES
WITH LESS OF A CHANCE IN THE WESTERN ZONES. TEMPERATURES SHOULD
REMAIN AT OR SLIGHTLY BELOW CIMO VALUES.

.TWC...NONE.

In the hours before

Special weather statement, Aug 2, 11:45 AM MST, 3 hours 45 minutes before

AZZ019-029>035-030700-

SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1145 AM MST FRI AUG 2 2002

.SYNOPSIS...GENERALLY AREA STILL PLENTY OF MOISTURE FOR STORMS BUT
FOCUS OF ACTIVITY TODAY WILL BE IN CENTRAL PORTION OF AREA AS CLOUDS
AND SHOWERS STILL CONTINUE IN EASTERN AREAS DUE TO HEAVY RAIN THAT
FELL THERE LAST NIGHT

.DISCUSSION...LARGE COMPLEX OF STORMS IN NORTHERN MEXICO AND COCHISE
COUNTY LAST NIGHT PRETTY MUCH DISSIPATED EXCEPT FOR A FEW LIGHT
SHOWERS LEFT OVER. MID LEVEL CIRCULATION SYSTEM CAN BE SEEN IN
SATELLITE PICTURE MOVING NORTHWARD IN FAR SOUTHEAST GRAHAM COUNTY
HAS RESULTED IN A LIGHT NORTHERLY MID LEVEL FLOW EASTERN
PINAL...EASTERN PIMA...AND SANTA CRUZ COUNTY...MODELS INDICATE THIS
FLOW WILL WEAKEN THIS AFTERNOON...TO LESS THAN 5 KNOTS...AND MAY
BECOME LIGHT SOUTHERLY.

ALOFT WINDS AT 300 MB WILL STILL BLOW ANVILS NORTH BUT THIS MAY WORK
IN FAVOR OF STORMS WEST OF THE MID LEVEL CIRCULATION SINCE THE
MOVEMENT WILL BE SOUTHERLY. MODELS INDICATE SOME DIVERGENCE ACROSS
AREA THIS AFTERNOON AND EVENING...ALTHOUGH NOT AS GOOD AS YESTERDAY.

WESTERN PIMA COUNTY STILL MISSING LOW LEVEL MOISTURE...EASTERN ZONES
CONVECTIVELY WORKED OVER FROM YESTERDAY...SO FOCUS OF ACTIVITY TODAY
WILL BE IN THE CENTRAL PORTION OF OUR WARNING AREA. PRIMARY PROBLEM
WILL BE HEAVY RAINFALL IN AN AREA BOUNDED BY SASABE...SELLS...
MARANA..SAN MIGUEL...SIERRA VISTA AND NOGALES...INCLUDING TUCSON.
LAPSE RATE SUGGEST SEVERE THUNDERSTORMS WILL NOT BE AN ISSUE...AND
HAVE LEFT GENERALLY BELOW CLIMATOLOGY...WITH MAIN CONCERN FROM WIND.

STORM MOTION WILL VARY IN RELATION TO MID LEVEL
CIRCULATION...GENERALLY SOUTH AT 5 MPH EXCEPT EASTERN ZONES WITH
STORM MOTION MORE TOWARDS THE NORTH AT 10 MPH.

The radar

The Tucson radar (KEMX), 112 km away, was scanning. The volume nearest the first event began at 22:11 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Pima

When: August 2, 3:30 PM MST to 5:00 PM MST
Where: Pima County, Arivaca
Property damage: $5,000
Reported by: AWOS,ASOS,MESONET,ETC
Coordinates: 32.097, -111.790 (the zone’s center; the record gives no point)

What these are

Flash Flood: Flooding that begins within six hours of the rain that causes it, or of a dam or levee failure or ice jam release, often with deadly speed.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Arizona in 2002 Every state in 2002 This day in weather history Warnings in Arizona, August 2002

Sources

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: 5312803.