Flash Flood in Arizona, September 8, 2003

Name: Flash Flood in Arizona, September 8, 2003
Start: 2003-09-08T15:30
End: 2003-09-08T16:30
Location: Arizona

September 8, 2003 · NWS TWC · 1 event in 1 county or zone

Strong thunderstorms over the town of Douglas produced heavy rain which caused street flooding. 80 inches of rain in less than an hour.

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.

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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.

Strong thunderstorms over the town of Douglas produced heavy rain which caused street flooding. A spotter recorded 1.80 inches of rain in less than an hour. Several roads were also closed due to flooding, including an intersection at Golf Course and Washington Avenue that was closed due to a foot of water.

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 Sep 8, 2:25 PM MST, 1 hour 5 minutes earlier.

Area forecast discussion, Sep 8, 2:25 PM MST, 1 hour 5 minutes before

SOUTHEAST ARIZONA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TUCSON AZ
225 PM MST MON SEP 8 2003

.SYNOPSIS...A TROUGH MOVING THROUGH THE WESTERN U.S. TUESDAY AND
EARLY WEDNESDAY WILL BRING AN ABUNDANCE OF MOISTURE OVER ARIZONA.
THIS TROUGH COMBINED WITH THE MOISTURE HAS THE POTENTIAL FOR
PRODUCING LOCALLY HEAVY RAIN ON TUESDAY.  DRYING AND CLEARER SKIES
WILL BEGIN WEDNESDAY NIGHT THROUGH THE WEEKEND. TEMPERATURES WILL
DROP BELOW SEASONAL NORMS ON TUESDAY WITH A SLOW WARMING TREND
THROUGH SATURDAY.

.DISCUSSION...MOISTURE AND DYNAMICS WILL COMBINE ON TUESDAY FOR
SHOWERS STATEWIDE. THIS SCENARIO IS NOT A BIG CHANGE FROM PREVIOUS
MODEL RUNS.  THE DURATION OF THIS EVENT HAS SOME VARIABILITY IN THE
MODELS.  THE 12Z GFS BEGINS DRYING OUT THE STATE ON WEDNESDAY
MORNING...WHERE AS THE ETA IS NOT QUITE AS RESPONSIVE.  GIVEN THESE
VARIATIONS...SCATTERED SHOWERS WILL BE IN THE FORECAST FOR TUESDAY
WITH ISOLATED SHOWERS TAPERING ON WEDNESDAY. DEPENDING ON THE
STABILITY OF THE ATMOSPHERE...A FLASH FLOOD WATCH MAY BE NEEDED FOR
TOMORROW.  WILL NOT ISSUE AT THIS TIME...ALTHOUGH THE POTENTIAL FOR
HEAVY RAIN IS PRESENT.

AS THE TROUGH SETTLES IN OVER THE WEST...HEIGHTS WILL DROP OVER US
AND LIKEWISE TEMPERATURES WILL DECREASE.  WITH THE DRIER AIR ON
THURSDAY AND FRIDAY...MORNING LOWS WILL FINALLY GET CLOSER TO
NORMAL.  MODEL VARIABILITY ON THE WEEKEND IS STILL HIGH.  HOWEVER
ALL MODELS TEND TO FAVOR A WESTERLY COMPONENT TO THE FLOW.  THIS
CHANGE IN THE PATTERN IMPLIES THE SUMMERTIME MONSOON CIRCULATION IS
LEAVING.  SOUTHERN ARIZONA MAY STILL HAVE DAYS WITH CONVECTION IN
SEPTEMBER ALTHOUGH WE ARE DEFINITELY SWITCHING TO A FALL PATTERN
WITH A DRIER WESTERLY OR SOUTHWESTERLY FLOW.

GWS

.TWC...NONE.

Hazardous weather outlook, Sep 8, 11:30 AM MST, 4 hours before

AZZ019-029>035-091400-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TUCSON AZ
1130 AM MST MON SEP 8 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ARIZONA

.DAY ONE...TODAY

SYNOPSIS...THUNDERSTORMS WILL CONTINUE TO DEVELOP ACROSS THE AREA
TODAY AS A TROUGH APPROACHES FROM THE NORTHWEST ADVECTING MOISTURE
INTO SOUTHERN ARIZONA. THE MAIN THREAT FROM THESE THUNDERSTORMS WILL
BE FOR MODERATE RAIN CAUSING LOCAL NUISANCE FLOODING. THERE IS THE
POTENTIAL...ALTHOUGH SLIGHT...FOR AN ISOLATED THUNDERSTORM TO CREATE
FLASH FLOODING.

DISCUSSION...THUNDERSTORMS HAVE ALREADY DEVELOPED THIS MORNING JUST
AS THEY DID YESTERDAY. BUT...A FEW THINGS HAVE CHANGED IN THE LAST
24 HOURS. SOME WARMING AND DRYING HAS TAKEN PLACE IN THE MID
LEVELS...THE CAP HAS LOWERED TO AROUND 650 MB AND A TROUGH IS
APPROACHING FROM THE NORTHWEST. THE TROUGH WILL HELP TO PULL SOME
ADDITIONAL MOISTURE INTO SOUTHERN ARIZONA FROM THE SOUTH.
ACTUALLY...MOISTURE HAS ALREADY BEGUN TO INCREASE AT THE LOW AND MID
LEVELS AS SEEN ON THE GOES TOTAL PRECIPITABLE WATER IMAGERY. THIS
ADVECTION OF MOISTURE WILL HELP TO PRODUCE SOME MODERATE RAIN
SHOWERS IF THUNDERSTORMS ARE ABLE TO BREAK THROUGH THE CAP. THE MID
AND UPPER LEVEL FLOW PATTERN IS SUCH THAT MOST MOVEMENT OF THE
STORMS WILL BE TO THE EAST AT ABOUT 10 MPH. THEREFORE...THE MAIN
THREAT FROM THESE STORMS IS FLASH FLOODING...HOWEVER THE THREAT WILL
BE LOW COMPARED TO CLIMATOLOGY.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH MONDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

EVANS

The radar

The Tucson radar (KEMX), 83 km away, was scanning. The volume nearest the first event began at 22:31 UTC.

Open the radar archive at this moment

Event by event

1 flash flood. Local standard time, as filed.

Flash Flood, Cochise

When: September 8, 3:30 PM MST to 4:30 PM MST
Where: Cochise County, Douglas
Reported by: TRAINED SPOTTER
Coordinates: 31.880, -109.751 (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

Every storm in Arizona in 2003 Every state in 2003 This day in weather history Warnings in Arizona, September 2003

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: 5337115.