Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 182, NWS Tucson, AZ

September 3, 2026Graham County, Arizona

NWS Tucson, AZ issued this flash flood warning at Sep 3, 2026, 3:17 PM MST for Graham County, Arizona. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Sep 3, 2026, 3:17 PM MST (22:17 UTC)
Expired
Sep 3, 2026, 6:15 PM MST
In force
3 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Flood severity
None

County Graham County, AZ

The radar

The Tucson radar (KEMX), 125 km from the middle of the area, began a volume at 22:20 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Sep 3, 3:40 PM MSTFLASH FLOOD10 S Safford, AZWater flowing across area roadways. 1.8 inches of rain so far.
Sep 3, 3:54 PM MSTRAIN 1.8210 S Safford, AZ1.82 inches in 30 mins.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this flash flood warning; the first came 23 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 10.3 hours before the alert went out and 227 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Phoenix, AZ at 12:00Z on 2026-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 556 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2026-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
556 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1454 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

599 
WGUS55 KTWC 032217
FFWTWC
AZC009-040115-
/O.NEW.KTWC.FF.W.0182.260903T2217Z-260904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
317 PM MST Thu Sep 3 2026

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  South Central Graham County in southeastern Arizona...

* Until 615 PM MST.

* At 317 PM MST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 1.5 inches of rain
  have fallen. Flash flooding is ongoing or expected to begin
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar indicated.

  IMPACT...Flash flooding of small creeks and streams, urban areas,
           highways, streets and underpasses as well as other poor
           drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Mainly rural areas of South Central Graham County.

This includes Route 191 between mile markers 108 and 112.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3272 10970 3269 10974 3263 10973 3267 10965
      3273 10966

FLASH FLOOD...RADAR INDICATED

$$

GLZ
2 follow-up statements
406 
WGUS75 KTWC 032258
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
358 PM MST Thu Sep 3 2026

AZC009-040115-
/O.CON.KTWC.FF.W.0182.000000T0000Z-260904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-
358 PM MST Thu Sep 3 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MST THIS
EVENING FOR SOUTH CENTRAL GRAHAM COUNTY...

At 358 PM MST, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1.5 and 2 inches of rain have
fallen. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar indicated.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Mainly rural areas of South Central Graham County.

This includes Route 191 between mile markers 108 and 112.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3272 10970 3269 10974 3263 10973 3267 10965
      3273 10966

FLASH FLOOD...RADAR INDICATED

$$

GLZ
865 
WGUS75 KTWC 040113
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
613 PM MST Thu Sep 3 2026

AZC009-040123-
/O.EXP.KTWC.FF.W.0182.000000T0000Z-260904T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Graham AZ-
613 PM MST Thu Sep 3 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM MST THIS EVENING FOR
SOUTH CENTRAL GRAHAM COUNTY...

The heavy rain has ended. Flash flooding is no longer expected to
pose a threat. Please continue to heed remaining road closures.

&&

LAT...LON 3272 10970 3269 10974 3263 10973 3267 10965
      3273 10966

$$

GLZ

What forecasters said that day

The local office's own words before this flash flood warning went out, 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 this flash flood warning went out at Sep 3, 12:08 PM MST, 3 hours 9 minutes earlier.

Area forecast discussion, Sep 3, 12:08 PM MST, 3 hours 9 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
1208 PM MST Thu Sep 3 2026

.SYNOPSIS...
Expect scattered to numerous thunderstorms each
afternoon and evening through the weekend as tropical moisture
moves in. The main threat will be heavy rainfall leading to
areas of flash flooding. High temperature will will fluctuate
between normal and a few degrees below normal.

&&

.DISCUSSION...
Southwest flow has set up across the region, pulling in tropical
moisture from Hurricane Marie. PWATS over Southeast Arizona are
at the 90th percentile or higher for this early September. The
above normal moisture will prime the day for heavy rainfall
risk. The latest CAM model have confidence for this afternoon
storms to produce up to 1-1.5 inches with pockets up to 2 inches
in a short amount of time. Ground conditions are primed and can
react quickly to heavy rainfall because of the previous 48 hour
rainfall. Areas south of Tucson will be the most susceptible to
quicker response in washes and creeks and heighten risk for
flash flooding. As result, there is a Flash Flood Watch for the
eastern Pima (including Tucson metro), Santa Cruz County, and
eastern Cochise County (Benson south to Sierra Vista/Hereford)
for today and through the early tomorrow morning. Several models
continue to show activity lasting through the nighttime and
adding more rainfall accumulation.

Tomorrow, moisture will shift more east of Tucson, allowing
Cochise, Graham, and Greenlee Counties to have better chances
for rain showers and thunderstorms. Rainfall amounts can be an
inch with localized higher amounts. WPC has a slight risk (<15%)
for flash flooding those counties. Thunderstorm activity will
drop around sunset.

Looking into the holiday weekend. The upper pattern will
generally stay the same with a closed low over the Pacific
Northwest and ridging to the east. Yet, the best chances for
rain showers and thunderstorms will mainly be confined to the
International Border and east of Tucson through the weekend.
Better widespread chances will return by next week with a
reemergence of deeper moisture.

Temperatures will be hovering near normal to slightly below
normal through the forecast period.

The 8-14 day CPC outlook has a 50-60% likely above normal
precipitation and 33-50% leaning above normal temperatures.

&&

.AVIATION...valid through 05/00Z.
SCT-BKN clouds 7-12k ft AGL through much of the forecast
period. Scattered TSRA/SHRA this afternoon and lasting through
the overnight period. Although the overnight TSRA/SHRA activity
will be more isolated. Near any thunderstorm will have strong
gusty winds, heavy rainfall, and brief lowering of ceilings.
Outside of thunderstorm winds, winds will be west to
southwesterly 5-10 kts and again after 04/18z. Light and terrain
driven at other times. Aviation discussion not updated for TAF
amendments.

&&

.FIRE WEATHER...
Expect daily scattered thunderstorms each
afternoon and evening today into early next week. There will be
some variation in coverage day to day, but expect the bulk of
the activity from central Pima County eastward. Heavy rainfall
leading to flash flooding will be the main threat. Temperatures
will be around normal to a few degrees below normal into early
next week. Minimum relative humidity values mainly 20 to 45
percent in the valleys and 30 to 60 percent in the mountains
over the next week. Winds will generally remain less than 15 mph
and terrain driven through the week.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Flood Watch through late tonight for AZZ503-504-507-513-514.

&&

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The office that day

Everything else NWS Tucson, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 3, 10:37 AM MSTFlood WatchTWCCochise, Graham, Pima, Pinal, Santa Cruz16 hr
Sep 3, 12:47 PM MSTAreal Flood AdvisoryTWCGraham99 min
Sep 3, 1:48 PM MSTAreal Flood AdvisoryTWCGraham3 hr
Sep 3, 2:26 PM MSTFlash Flood WarningTWCGraham, Pinal5 hr
Sep 3, 2:53 PM MSTFlash Flood WarningTWCCochise3 hr
Sep 3, 3:02 PM MSTAreal Flood AdvisoryTWCGraham118 min
Sep 3, 3:02 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Sep 3, 3:21 PM MSTFlash Flood WarningTWCCochise3 hr
Sep 3, 3:28 PM MSTAreal Flood AdvisoryTWCPima2 hr
Sep 3, 3:39 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Sep 3, 3:43 PM MSTFlash Flood WarningTWCCochise3 hr
Sep 3, 3:54 PM MSTFlash Flood WarningTWCCochise3 hr
Sep 3, 4:35 PM MSTAreal Flood AdvisoryTWCPima115 min

Nearby

Flash Flood Warnings in Arizona, 2026Every flash flood warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.