Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 121, NWS Tucson, AZ

August 10, 2026Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 10, 2026, 6:28 PM MST for Pima County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 10, 2026, 6:28 PM MST (01:28 UTC)
Expired
Aug 10, 2026, 9:30 PM MST
In force
3 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Flood severity
None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 140 km from the middle of the area, began a volume at 01:29 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 00:00Z, 1.5 hours before the alert went out and 185 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 00:00Z on 2026-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 484 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 00:00Z on 2026-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 23 square meters per square second.1939Sfc1 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
484 J/kg
Mixed-layer CIN
-154 J/kg
Mixed-layer LCL
2675 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
23 m²/s²
0-3 km storm-relative helicity
68 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

175 
WGUS55 KTWC 110128
FFWTWC
AZC019-110430-
/O.NEW.KTWC.FF.W.0121.260811T0128Z-260811T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
628 PM MST Mon Aug 10 2026

The National Weather Service in Tucson has issued a

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

* Until 930 PM MST.

* At 628 PM MST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 0.5 and 1.5 inches of
  rain have fallen. Additional rainfall amounts up to 1 inch are
  possible in the warned area. 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...
  San Miguel, Vamori, South Komelik, Choulic, Newfield, Coldfields,
  Itak, Kots Kug, Papago Farms and Hashan Chuchg.

This includes the following streams and drainages...
  Chutum Vaya Wash, Baboquivari Wash, Big Wash, Topawa Wash, Vamori
  Wash, Sells Wash, Chukut Kuk Wash and San Simon Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain.
Washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3175 11241 3188 11229 3191 11212 3181 11206
      3172 11174 3154 11171

FLASH FLOOD...RADAR INDICATED

$$

KJS
2 follow-up statements
572 
WGUS75 KTWC 110236
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
736 PM MST Mon Aug 10 2026

AZC019-110430-
/O.CON.KTWC.FF.W.0121.000000T0000Z-260811T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
736 PM MST Mon Aug 10 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM MST THIS
EVENING FOR SOUTH CENTRAL PIMA COUNTY...

At 736 PM MST, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1 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...
  San Miguel, Vamori, South Komelik, Choulic, Newfield, Coldfields,
  Itak, Kots Kug, Papago Farms and Hashan Chuchg.

This includes the following streams and drainages...
  Chutum Vaya Wash, Baboquivari Wash, Big Wash, Topawa Wash, Vamori
  Wash, Sells Wash, Chukut Kuk Wash and San Simon Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Remain alert for flooding even in locations not receiving rain.
Washes, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3175 11241 3188 11229 3191 11212 3181 11206
      3172 11174 3154 11171

FLASH FLOOD...RADAR INDICATED

$$

KJS
959 
WGUS75 KTWC 110423
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
923 PM MST Mon Aug 10 2026

AZC019-110433-
/O.EXP.KTWC.FF.W.0121.000000T0000Z-260811T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
923 PM MST Mon Aug 10 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 930 PM MST THIS EVENING FOR
SOUTH CENTRAL PIMA COUNTY...

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

A Flood Watch remains in effect until 1000 PM MST for a portion of
Southeast Arizona.

&&

LAT...LON 3175 11241 3188 11229 3191 11212 3181 11206
      3172 11174 3154 11171

$$

KJS

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 Aug 10, 2:08 PM MST, 4 hours 20 minutes earlier.

Area forecast discussion, Aug 10, 2:08 PM MST, 4 hours 20 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
Issued by National Weather Service Phoenix AZ
208 PM MST Mon Aug 10 2026

.SYNOPSIS...
Expect daily chances of showers and thunderstorms much of this
week. While there will be day to day variability, Monday and
Wednesday look to be the most active days. Storm coverage will
be much less Friday into the weekend. High temperatures will be
near normal today and Tuesday with additional lowering to around
3 to 6 degrees below normal Wednesday and Thursday before
temperatures warm again into the weekend.

&&

.DISCUSSION...
As of 2 PM, thunderstorms are beginning to initiate in the
expected areas in the White and Chirichua Mountains. Activity is
expected to increase in coverage and intensity this afternoon
and evening. The multi-hazard impacts of severe winds and flash
flooding are still on track.

Looking to tomorrow, there can be another day of multi-hazard
impacts of severe wind and flash flooding. For the strong to
severe winds, the latest 11/15Z U of A WRF HRRR (usually the
most bullish of the models) is showing the potential for a line
of thunderstorms forming forming from initial activity the
Huachucha Mountains/Santa Cruz County moving northwest towards
the Tucson Metro into Central Pima and Pinal Counties. This is
the reasonable worst case scenario, with the more likely
scenario being thunderstorms being strong to severe but more
scattered in nature, not in a formal line. The 11/12Z HREF is
showing a 10% probability of 50 kts within 40 km in mainly
Cochise County with this run. I wouldn't be surprised if future
HREF runs spreads this contour westward as it accounts for the
HRRR's latest runs that are latching onto more activity and
stronger outflow winds. Moisture from the west and south moves
back into the eastern valleys, allowing for more of a flash
flood threat for areas Tucson eastward. The 11/12Z HREF is
highlighting these areas for 3 hour probabilities of storm
totals between 1-2 inches, with a localized threat for 3 inches.

The elevated monsoonal pattern continues into Thursday this week
with day to day variability. With the high pressure staying in
the four corners region, the easterly flow aloft will keep the
ability for the afternoon/early evening activity to move out of
the area and allow for the atmosphere to recharge each night.
The only caveat to this would be any overnight convection that
could hamper and/or shut down the activity for the next day.

On the bright side, the increased thunderstorm activity will
'cool' high temperatures, especially Tuesday through Thursday.
Temperatures begin to warm up Friday into early next week.

&&

.AVIATION...Valid through 12/00Z.
Now thru 11/06z, SCT -SHRA/-TSRA with clouds 8-12k ft AGL.
Isold vsbys 1SM +TSRA. Gusty erratic winds of 35-50 kts possible
with any thunderstorm. Outside of storms SFC winds WLY/NWLY at
8-12 kts with occasional afternoon gusts to 20 kts this
afternoon and evening. Aft 11/06z, ISOLD -SHRA mainly W of KTUS
diminishing. Lower cloud decks also diminishing. SFC winds light
and terrain driven after 11/06Z. Additional SHRA/TSRA chances
aft 11/18Z thru the end of the period. Aviation discussion not
updated for TAF amendments.

&&

.FIRE WEATHER...
Expect daily afternoon and evening showers and thunderstorms
through Thursday with less coverage Friday into next weekend.
Minimum relative humidity will be 20-40 percent Monday through
Thursday lowering to around 15-30 percent thereafter.
Temperatures will be near normal through Tuesday, dropping to
below normal Wednesday and Thursday, then warming again next
weekend. Outside of thunderstorms, winds terrain driven to
around 10 mph with occasional afternoon gusts to 20 mph.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
Flood Watch from 2 PM MST this afternoon through this evening
for AZZ501>506-514-515.

Flood Watch from 2 PM MST Tuesday through 11 PM MST Tuesday for
AZZ503-504-507>509-511>514.

&&

JT

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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 5:11 PM MSTFlash Flood WarningTWCPima3 hr
Aug 10, 5:24 PM MSTSevere Thunderstorm WarningTWCCochise28 min
Aug 10, 5:36 PM MSTSevere Thunderstorm WarningTWCPima39 min
Aug 10, 6:01 PM MSTFlash Flood WarningTWCPima3 hr
Aug 10, 6:03 PM MSTSevere Thunderstorm WarningTWCPima42 min
Aug 10, 6:12 PM MSTSevere Thunderstorm Warning Considerable damage threatTWCPima48 min
Aug 10, 6:14 PM MSTSevere Thunderstorm WarningTWCPima46 min
Aug 10, 6:40 PM MSTSevere Thunderstorm WarningTWCPima50 min
Aug 10, 6:55 PM MSTSevere Thunderstorm WarningTWCPima31 min
Aug 10, 6:58 PM MSTAreal Flood AdvisoryTWCPima3 hr
Aug 10, 7:02 PM MSTFlash Flood WarningTWCPima3 hr
Aug 10, 7:04 PM MSTSevere Thunderstorm WarningTWCPima41 min
Aug 10, 7:12 PM MSTSevere Thunderstorm WarningTWCPima33 min
Aug 10, 7:17 PM MSTFlash Flood Warning Considerable damage threatTWCGraham3 hr
Aug 10, 7:18 PM MSTSevere Thunderstorm WarningTWCCochise, Graham42 min
Aug 10, 7:26 PM MSTSevere Thunderstorm WarningTWCPima49 min
Aug 10, 7:45 PM MSTSevere Thunderstorm WarningTWCCochise45 min
Aug 10, 8:02 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Aug 10, 8:27 PM MSTFlash Flood WarningTWCGraham3 hr
Aug 10, 8:35 PM MSTSevere Thunderstorm WarningTWCGraham40 min
Aug 10, 9:06 PM MSTAreal Flood AdvisoryTWCPima114 min
Aug 10, 9:23 PM MSTSevere Thunderstorm WarningTWCGraham52 min
Aug 11, 6:02 AM MSTAreal Flood AdvisoryTWCPima118 min
Aug 11, 8:27 AM MSTAreal Flood AdvisoryTWCPima4 hr
Aug 11, 4:39 PM MSTSevere Thunderstorm WarningTWCGreenlee51 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.