Flash Flood, Pima
- When
- August 30, 4:20 PM MST to 6:00 PM MST
- Where
- Pima County, 5 mi W of Marana
- Reported by
- LAW ENFORCEMENT
- Coordinates
- 32.097, -111.790 (the zone’s center; the record gives no point)
Flash Flood in Arizona, August 30, 2001
25 inches of rain in one hour and the tributary of Blanco wash was flooded.
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
The toll
- Deaths
- 0
- Injuries
- 0
- Property damage
- None recorded
- 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.
A spotter reported 2.25 inches of rain in one hour and the tributary of Blanco wash was flooded.
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 30, 2:30 PM MST, 1 hour 50 minutes earlier.
Area forecast discussion, Aug 30, 2:30 PM MST, 1 hour 50 minutes before
SOUTHEAST ARIZONA FORECAST DISCUSSION NATIONAL WEATHER SERVICE TUCSON AZ 230 PM MST THU AUG 30 2001 .SYNOPSIS...MONSOON MOISTURE WILL GENERATE AFTERNOON AND EVENING THUNDERSTORMS...WITH SOME HEAVY RAIN POSSIBLE TONIGHT. THEN THE RAIN CHANCES WILL BE FROM TUCSON AND EAST FRIDAY AND SATURDAY. .DISCUSSION...ANOTHER STRONG SURGE OF MOISTURE THIS MORNING WITH PRECIPITABLE WATER VALUES WELL OVER AN INCH. STORMS NOW DEVELOPING OVER MOUNTAINS EXPECTED TO DEVELOP IN VALLEYS IN AFTERNOON HOURS...WITH HEAVY RAIN AND GUSTY WINDS POSSIBLE. SOME AREAS WILL GET MORE THAN 15 DROPS OF RAIN. MODELS STILL INSISTING ON DRYING...WILL TAKE US TO LOW PACKAGE FOR TOMORROW...NOT THAT I BELIEVE THE DRYING BUT GOING MORE WITH UP/DOWN DAY SCENARIO. WILL KEEP IT DOWN AGAIN SATURDAY AFTERNOON BUT SHOULD SEE SOME INCREASE SATURDAY EVENING. REMNANTS OF FLOSSIE MAY SPRUCE THINGS UP SUNDAY...DIFFICULT TO TELL WHAT EXACT IMPACT WILL BE BUT HAVE PUT ALL OF THE AREA IN CHANCE WORDING. OTHERWISE THE EXTENDED IS STANDARD MONSOON PACKAGE. .TWC...NONE.
In the hours before
Special weather statement, Aug 30, 11:55 AM MST, 4 hours 25 minutes before
AZZ019-029>035-310700- SOUTHEAST ARIZONA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE TUCSON AZ 1155 AM MST THU AUG 30 2001 .SYNOPSIS...THE COMBINATION OF A MOIST ATMOSPHERE...DAYTIME HEATING AND SOME WEAK VERTICAL MOTION OVER THE AREA...WILL LEAD TO THUNDERSTORM ACTIVITY LATER THIS AFTERNOON AND EVENING...ESPECIALLY FROM TUCSON EAST. .DISCUSSION...LOW LEVEL MOISTURE CONTINUES TO STREAM NORTHWARD OFF THE GULF OF CALIFORNIA AND FROM NORTHERN MEXICO. DEWPOINTS HAVE RISEN INTO THE LOWER 60S...WITH PRECIPITABLE WATERS OF 1 TO 1.4 INCHES ACROSS ALL OF SOUTHERN ARIZONA. A JET STREAK ALSO EXTENDS FROM SOUTHERN CALIFORNIA...ACROSS SOUTHERN ARIZONA AND INTO WEST TEXAS. THIS WILL PROVIDE SOME UPPER LEVEL DYNAMIC SUPPORT FOR STORM DEVELOPMENT. MODERATE TO TOWERING CUMULUS CLOUDS ARE ALREADY FORMING AND UNLIKE YESTERDAY ARE NOT CONFINED TO JUST THE HIGHER TERRAIN. TEMPERATURES IN THE MID AND UPPER LEVELS OF THE ATMOSPHERE REMAIN COOL...WITH LITTLE IF ANY CAPPING INVERSION. STORMS THAT DEVELOP LATER THIS AFTERNOON AND EVENING WILL HAVE THE POTENTIAL FOR STRONG WINDS AND FLASH FLOODING. THE RISK OF SEVERE THUNDERSTORMS AND FLASH FLOODING INCREASES TO THE SOUTH AND EAST OF TUCSON METRO AREA. WILL GO NEAR CLIMATOLOGY FOR THE RISK OF SEVERE STORMS AND FLASH FLOODING WEST OF TUCSON AND ABOVE CLIMATOLOGY FROM TUCSON EAST. STORM MOTION WILL BE SOUTHEAST AT 10 TO 15 MPH. ZELL
The radar
The Tucson radar (KEMX), 112 km away, was scanning. The volume nearest the first event began at 23:21 UTC.
Event by event
1 flash flood. Local standard time, as filed.
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
- Hail and Damaging Winds in Virginia, August 30, 2001
- Rip Current in California, August 30, 2001
- Flash Flooding in Texas, August 30, 2001
- Tornadoes and Flash Flooding in Texas, August 30 to 31, 2001
- Flash Flooding and Hail in Maryland, August 30, 2001
- Flash Flood in Texas, August 30, 2001
- Damaging Wind in Michigan, August 30, 2001
- Flash Flood in Texas, August 30, 2001
- Flash Flood in Texas, August 30, 2001
- Damaging Wind in Missouri, August 30, 2001
- Hail and Damaging Winds in Missouri, August 30, 2001
- Flash Flooding in Texas, August 30, 2001
More
Every storm in Arizona in 2001Every state in 2001This day in weather historyWarnings in Arizona, August 2001
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: 5259998.