Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 133, NWS Tucson, AZ

August 13, 2026Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Aug 13, 2026, 3:20 AM MST for Pima County, Arizona. It was in force for 3 hr. 1 report 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
Aug 13, 2026, 3:20 AM MST (10:20 UTC)
Expired
Aug 13, 2026, 6:15 AM MST
In force
3 hr
Issued by
NWS Tucson, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Pima County, AZ

The radar

The Tucson radar (KEMX), 43 km from the middle of the area, began a volume at 10:20 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
Aug 13, 5:54 AM MSTFLASH FLOOD11 Ene Tucson, AZRoad closure due to flash flooding.

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 2 storm reports to this flash flood warning; the first came 149 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 00:00Z, 10.3 hours before the alert went out and 183 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 2026-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 559 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 2026-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
559 J/kg
Mixed-layer CIN
-32 J/kg
Mixed-layer LCL
2150 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

778 
WGUS55 KTWC 131020
FFWTWC
AZC019-131315-
/O.NEW.KTWC.FF.W.0133.260813T1020Z-260813T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
320 AM MST Thu Aug 13 2026

The National Weather Service in Tucson has issued a

* Flash Flood Warning for...
  Eastern Pima County in southeastern Arizona...

* Until 615 AM MST.

* At 320 AM MST, Pima County Regional Flood Control District reported
  flash flooding on the Tanque Verde and Aqua Caliente Washes from
  heavy rain this morning that has lead to significant rises in these
  washers. Between 1 and 3 inches of rain has been recorded this
  morning. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Heavy rain producing
           flash flooding.

  SOURCE...Emergency management reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Tanque Verde and Saguaro National Park East.

This includes the following streams and drainages...
  Agua Caliente Wash, Deer Creek, Chimney Rock Creek, Tanque Verde
  Wash, Bear Creek and Rincon Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the
dangers of flooding.

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

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 3232 11050 3231 11048 3225 11048 3222 11053
      3219 11065 3225 11073 3229 11072 3232 11060

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$
1 follow-up statement
697 
WGUS75 KTWC 131306
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
606 AM MST Thu Aug 13 2026

AZC019-131316-
/O.EXP.KTWC.FF.W.0133.000000T0000Z-260813T1315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
606 AM MST Thu Aug 13 2026

...FLASH FLOOD WARNING WILL EXPIRE AT 615 AM MST THIS MORNING FOR
EASTERN PIMA COUNTY...

The heavy rain has ended. Flood waters are slowly receding in the
Tanque Verde and Aqua Caliente Washes. Flooding is no longer expected
to pose a threat. Please continue to heed remaining road closures.

&&

LAT...LON 3232 11050 3231 11048 3225 11048 3222 11053
      3219 11065 3225 11073 3229 11072 3232 11060

$$

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 12, 3:12 PM MST, 12 hours 8 minutes earlier.

Area forecast discussion, Aug 12, 3:12 PM MST, 12 hours 8 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
312 PM MST Wed Aug 12 2026

.SYNOPSIS...A shifting weather pattern will support scattered
showers and storms the next few days. The strongest storms could
produce heavy rainfall and flash flooding with rainfall rates around
three quarters of an inch to an inch and a half per hour. Storm
activity will clear out Friday into the weekend bringing warmer and
drier conditions and moderate HeatRisk.

&&

.DISCUSSION...Cloud cover led to a pleasant morning with lows in the
60s and 70s across southeast Arizona. There were a few lingering
showers and storms from overnight convection. Overall, we saw a
slowdown in the convective activity through the morning hours. Now,
we start to see a ramp up again with showers and storms so far
forming mainly south and east of Tucson in the White Mountains.

The atmospheric environment this afternoon favors isolated to
scattered storms capable of producing moderate to heavy rainfall.
The Weather Prediction Center has Graham, Greenlee, Cochise, Santa
Cruz, Pinal, and eastern Pima counties in a slight risk for
excessive rainfall that could lead to flash flooding. Hourly
rainfall rates could be between 0.75 to 1.5 inches per hour, which
would be enough to result in localized instances of flash flooding.

As a upper level trough approaches the area from the west coast,
flow will become more southwesterly promoting lift and another round
of nocturnal showers and thunderstorms from late tonight into early
tomorrow morning mainly north and east of Tucson. Cannot rule out
isolated flash flooding over Graham/Greenlee and Pinal counties with
this activity.

For the remainder of the work week into the weekend we will see a
gradual downturn in the coverage and intensity of showers and
storms. Not to say that we won't have any activity at all, but we
start to minimize the necessary ingredients for widespread showers
and storms. We lose our lift provided by the upper level trough
which will usher dry air aloft into the region. Any storms that do
form will be from recycled moisture in the boundary layer (low
levels) of the atmosphere. The best chances (10-30%) will be mainly
for areas east and south of Tucson.

Early next week chances for showers and storms may return as an
easterly wave moves over northern Mexico. This would bring some
moisture and dynamics back into play supporting an uptick in storm
activity. But we could also see the moisture slow to return and
temperatures warming up into 105 territory for the Tucson Metro.

&&

.AVIATION...Valid through 14/00Z.
SCT-BKN 7-11k ft AGL thru much of the valid pd. SCTD -SHRA/-TSRA
with isold vsbys 1SM +TSRA. Gusty erratic winds of 35-45 kts
possible with any thunderstorm. Outside of storms SFC winds WLY/NWLY
at 8-12 kts with ocnl gusts to 20 kts. SFC winds light and terrain
driven between 13/06Z and 13/16Z. Tomorrow, chances for showers and
storms again mainly east of KAVQ to KOLS line. Aviation discussion
not updated for TAF amendments.

&&

.FIRE WEATHER...The combination of a shifting weather pattern
aloft and deep moisture residing across the region will result in
scattered showers and thunderstorms the next couple days across
Southeast Arizona with the potential for heavy rain. Although most
of the storms will produce between a half and one inch of rain, the
stronger storms are capable of producing locally heavier amounts
between 1-3 inches. Otherwise, a drier southwest flow aloft will
bring a downturn in daily storm activity Friday into the weekend.
Minimum relative humidity will be 20-40 percent through Thursday
lowering to around 15-30 percent thereafter. Temperatures will be
below normal today and Thursday, then warm up again for the weekend.
Outside of thunderstorms, winds terrain driven to around 10 mph with
occasional afternoon gusts to 20 mph.

&&

.HYDROLOGY...Early this morning the Vamori Wash near the village of
Santa Cruz in central Pima County showed a significant rise, topping
out near flood stage. A Flood Advisory remains in effect until 4 pm
MST near the village of Santa Cruz on Tohono O'odham Nation in
central Pima County. We are also keeping an eye on the Santa Cruz
River near Tubac and the San Pedro River near Palominas for
potentially heavy rainfall that could support significant rises.
Right now, these points are forecast to remain below action stage.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...None

&&

DVS

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The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 9:58 PM MSTAreal Flood AdvisoryTWCPima28 hr
Aug 12, 11:40 PM MSTAreal Flood AdvisoryTWCPima, Pinal2 hr
Aug 13, 12:28 AM MSTFlash Flood WarningTWCPinal3 hr
Aug 13, 1:49 AM MSTAreal Flood AdvisoryTWCPima3 hr
Aug 13, 8:56 AM MSTAreal Flood AdvisoryTWCPima6 hr
Aug 13, 11:19 AM MSTExtreme Heat WatchTWCGraham, Greenlee, Pima, Pinal46 hr
Aug 13, 12:35 PM MSTFlash Flood WarningTWCCochise3 hr
Aug 13, 1:00 PM MSTFlash Flood WarningTWCGraham3 hr
Aug 13, 1:37 PM MSTFlash Flood WarningTWCCochise5 hr
Aug 13, 2:11 PM MSTSevere Thunderstorm WarningTWCCochise49 min
Aug 13, 2:45 PM MSTAreal Flood AdvisoryTWCSanta Cruz3 hr
Aug 13, 2:47 PM MSTAreal Flood AdvisoryTWCPima, Santa Cruz3 hr
Aug 13, 4:38 PM MSTFlash Flood WarningTWCPima3 hr

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.