Alert archive / Arizona / Flash Flood Warnings in 2026

Flash Flood Warning 217, NWS Tucson, AZ

September 16, 2026Pima County, Arizona

NWS Tucson, AZ issued this flash flood warning at Sep 16, 2026, 11:06 AM 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
Sep 16, 2026, 11:06 AM MST (18:06 UTC)
Expired
Sep 16, 2026, 2:00 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), 104 km from the middle of the area, began a volume at 18:08 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 12:00Z, 6.1 hours before the alert went out and 140 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 2026-09-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1115 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 2026-09-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 46 square meters per square second.193958Sfc1 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
1115 J/kg
Mixed-layer CIN
-35 J/kg
Mixed-layer LCL
1275 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
46 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

523 
WGUS55 KTWC 161806
FFWTWC
AZC019-162100-
/O.NEW.KTWC.FF.W.0217.260916T1806Z-260916T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Tucson AZ
1106 AM MST Wed Sep 16 2026

The National Weather Service in Tucson has issued a

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

* Until 200 PM MST.

* At 1106 AM MST, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Between 1 and 1.5 inches of rain
  have fallen. Additional rainfall amounts of 0.5 to 1.5 inches 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 Pedro, Queens Well, Santa Rosa Ranch and Pan Tak.

This includes Route 86 between mile markers 135 and 139.

This includes the following streams and drainages...
  Aguirre Wash, Anegan Wash, Viopuli Wash, Pan Tak Wash, House Wash,
  Sil Nakya Wash, Mendoza Wash and San Vicente 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 3234 11178 3231 11182 3221 11180 3216 11177
      3209 11170 3207 11165 3204 11160 3201 11156
      3206 11144 3214 11153 3228 11160 3232 11166
      3241 11175

FLASH FLOOD...RADAR INDICATED

$$

JRM
2 follow-up statements
857 
WGUS75 KTWC 162029
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
129 PM MST Wed Sep 16 2026

AZC019-162100-
/O.CON.KTWC.FF.W.0217.000000T0000Z-260916T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
129 PM MST Wed Sep 16 2026

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 2 PM MST THIS
AFTERNOON FOR NORTH CENTRAL PIMA COUNTY...

At 129 PM MST, Doppler radar indicated thunderstorms producing heavy
rain across the warned area. Between 1 and 1.5 inches of rain have
fallen. Additional rainfall amounts of 0.5 to 1.5 inches 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 Pedro, Queens Well, Santa Rosa Ranch and Pan Tak.

This includes Route 86 between mile markers 135 and 139.

This includes the following streams and drainages...
  Mendoza Wash, House Wash, Sil Nakya Wash, Aguirre Wash, Viopuli
  Wash, San Vicente Wash, Anegan Wash and Pan Tak 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 3234 11178 3231 11182 3221 11180 3216 11177
      3209 11170 3207 11165 3204 11160 3201 11156
      3206 11144 3214 11153 3228 11160 3232 11166
      3241 11175

FLASH FLOOD...RADAR INDICATED

$$

GLZ
452 
WGUS75 KTWC 162102
FFSTWC

Flash Flood Statement
National Weather Service Tucson AZ
202 PM MST Wed Sep 16 2026

AZC019-162112-
/O.EXP.KTWC.FF.W.0217.000000T0000Z-260916T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Pima AZ-
202 PM MST Wed Sep 16 2026

...FLASH FLOOD WARNING HAS EXPIRED FOR NORTH CENTRAL PIMA COUNTY...

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

A Flood Watch remains in effect until 1100 PM MST Wednesday for a
portion of Southeast Arizona.

&&

LAT...LON 3234 11178 3231 11182 3221 11180 3216 11177
      3209 11170 3207 11165 3204 11160 3201 11156
      3206 11144 3214 11153 3228 11160 3232 11166
      3241 11175

$$

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 16, 3:09 AM MST, 7 hours 57 minutes earlier.

Area forecast discussion, Sep 16, 3:09 AM MST, 7 hours 57 minutes before
Area Forecast Discussion
National Weather Service Tucson AZ
309 AM MST Wed Sep 16 2026

.SYNOPSIS...A weather system moving in from northern Mexico
today will bring widespread showers and thunderstorms into
Thursday morning which will be capable of producing heavy
rainfall. Drier conditions move in Friday limiting the daily
chance through this weekend into early next week. High
temperatures will be below normal today and Thursday, then be
around normal Friday into early next week.

&&

.DISCUSSION...A very moist atmosphere for mid-September is in
place awaiting the dynamics from a small upper low that was
south of Hermosillo, MX this morning. This feature will swing
north across the area today bringing moderate to heavy rainfall
to portions of southeast Arizona and the increased chances for
flash flooding due to moist antecedent conditions. A Flash Flood
Watch is in effect until 11 pm tonight.

Satellite imagery showed southerly flow across the area which
continues to slowly increase PWAT values into the 1.3" to 1.8"
range which is 175%-200% of normal. Radar showing initial area
of showers/storms moving into southern Cochise county. Expect
areal coverage of showers/storms to slowly increase over the
next 2-5 hours before more rapid development occurs later this
morning as the upper low edges closer to the Intl border. Hourly
rainfall rates of 1"-2.5" with some of the heavy showers with
some storms over 3". The Weather Prediction Center has a
Moderate risk for excessive rainfall for portions of Pima,
Pinal, and Graham counties today.

Thursday: Precipitable water remains elevated for this time of
year with a slight risk for excessive rainfall continuing east
and south of Tucson. Showers and storms that develop will still
have the potential for locally heavy rainfall, but without the
disturbance nearby there will be a lack of forcing to help aid
in higher rainfall rates like Wednesday.

Friday through Tuesday: Drier air finally begins to filter into
southeast Arizona as flow aloft shifts more
westerly/southwesterly. This could help limit thunderstorm
activity somewhat and keep activity mainly east and south of
Tucson. High temperatures return to at or slightly above normal.

8 to 14 day outlooks (Wed Sep 23 to Tue Sep 29)
Temperature: Leaning above normal, 39-42% chance
Precipitation: Leaning above normal, 39-42% chance

&&

.AVIATION...Valid thru 17/12Z.
SCT-BKN clouds 7k-10k ft AGL with ISOLD -SHRA/-TSRA bcmg thru
much of the valid pd. After 16/17Z, SCT-NUM SHRA/TSRA thru end
of valid pd. VSBYS nr 1 SM at times with SHRA+/TS. Gusty and
erratic outflow winds to around 35-45 kts nr strongest TS.
Outside of TS, SFC winds SLY/SWLY at 7-12 kts. Aviation
discussion not updated for TAF amendments.

&&

.FIRE WEATHER...A weather system moving in from northern Mexico
today will bring widespread showers and thunderstorms into
Thursday morning which will be capable of producing heavy
rainfall. Drier conditions move in Friday limiting the daily
chance through this weekend into early next week. High
temperatures will be below normal today and Thursday, then be
around normal Friday into early next week. Min RH values mainly
20 to 45 percent in the valleys and 35 to 65 percent in the
mountains over the next week. RH recoveries will continue to be
excellent overnight. Winds will generally remain less than 15
mph and terrain driven. Gusty and erratic winds will accompany
thunderstorms.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...
 Flood Watch through this evening for AZZ501>515.

&&

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The office that day

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

IssuedProductOfficeCountiesLasted
Sep 16, 5:40 AM MSTAreal Flood AdvisoryTWCCochise2 hr
Sep 16, 6:58 AM MSTAreal Flood AdvisoryTWCGraham3 hr
Sep 16, 8:09 AM MSTAreal Flood AdvisoryTWCGraham, Greenlee5 hr
Sep 16, 9:27 AM MSTAreal Flood AdvisoryTWCPima2 hr
Sep 16, 11:40 AM MSTFlash Flood WarningTWCPima5 hr
Sep 16, 12:18 PM MSTSevere Thunderstorm WarningTWCPinal18 min
Sep 16, 12:59 PM MSTAreal Flood AdvisoryTWCPinal2 hr
Sep 16, 1:12 PM MSTFlash Flood WarningTWCPima3 hr
Sep 16, 1:16 PM MSTAreal Flood AdvisoryTWCPima108 min
Sep 16, 2:23 PM MSTAreal Flood AdvisoryTWCCochise2 hr
Sep 16, 3:04 PM MSTFlash Flood WarningTWCPima116 min
Sep 16, 3:11 PM MSTFlash Flood WarningTWCCochise3 hr
Sep 16, 3:57 PM MSTFlash Flood Warning Considerable damage threatTWCCochise3 hr
Sep 16, 4:22 PM MSTAreal Flood AdvisoryTWCCochise15 min
Sep 16, 4:37 PM MSTAreal Flood AdvisoryTWCPima113 min
Sep 16, 4:37 PM MSTFlash Flood WarningTWCCochise113 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.