Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 79, NWS Phoenix, AZ

July 25, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 25, 2021, 10:16 AM MST for Maricopa County, Arizona. It was in force for 4 hr. 4 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
Jul 25, 2021, 10:16 AM MST (17:16 UTC)
Expired
Jul 25, 2021, 2:15 PM MST
In force
4 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 56 km from the middle of the area, began a volume at 17:17 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
Jul 25, 10:55 AM MSTFLASH FLOOD2 Nne Sun City, AZMULTIPLE WATER RESCUES REPORTED IN SUN CITY, INCLUDING 98TH AVE AND GRANADA, 107TH AVE AND MOUNTAIN VIEW, AND 99TH AVE AND BURNS.
Jul 25, 11:06 AM MSTFLASH FLOOD1 Ne Sun City, AZFLOOD CONTROL CHANNEL ALONG CENTER OF 99TH AVE WAS OVERFLOWING ONTO THE STREET. MCSO DEPUTY STOPPING SOUTH-BOUND TRAFFIC AT DESERT ROCK DRIVE (SOUTH OF BELL RD.) DUE TO DEPTH OF WATER JUST SOUTH OF THERE.
Jul 25, 11:37 AM MSTFLASH FLOOD2 Ene Tolleson, AZSEVERAL LANES ON INTERSTATE 10 NEAR 75TH AVE AND 91ST AVE ARE FLOODED AND IMPASSABLE.
Jul 25, 11:57 AM MSTFLASH FLOOD3 N Sun City, AZWATER RESCUE AT 107TH AVE AND UNION HILLS.

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

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 5.3 hours before the alert went out and 191 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, Tuscon, AZ at 12:00Z on 2021-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 151 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 12:00Z on 2021-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 95 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
151 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
521 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
95 m²/s²
0-3 km storm-relative helicity
103 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

767 
WGUS55 KPSR 251716
FFWPSR
AZC013-252115-
/O.NEW.KPSR.FF.W.0079.210725T1716Z-210725T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1016 AM MST Sun Jul 25 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Maricopa County in south central Arizona...

* Until 215 PM MST.

* At 1016 AM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  0.5 and 1.5 inches of rain have fallen. Additional rainfall 
  amounts of 1 to 2 inches are possible in the warned area. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar and automated gauges.

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

* Some locations that will experience flash flooding include...
  Phoenix, Glendale, Peoria, Surprise, Avondale, Goodyear, El 
  Mirage, Tolleson, Youngtown, Laveen, Sun City, Sun City West, 
  Glendale Sports Complex, Downtown Glendale, Camelback Ranch, 
  Downtown Peoria, Phoenix International Raceway, Arrowhead Mall, 
  South Phoenix and Komatke.

This includes the following highways...
	AZ Interstate 10 between mile markers 132 and 141.
	AZ Route 101 between mile markers 10 and 18.
	US Highway 60 between mile markers 141 and 150.

This includes the following streams and drainages...
  Agua Fria River, Corgett Wash, Cave Creek, Beardsley Canal, Salt 
  River, Gila River, New River, Skunk Creek and North Canyon Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3329 11220 3331 11236 3336 11232 3359 11230
      3366 11238 3369 11236 3372 11221 3364 11216
      3351 11215 3343 11212 3337 11204 3329 11219

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

SDB
1 follow-up statement
285 
WGUS75 KPSR 251800
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1100 AM MST Sun Jul 25 2021

AZC013-252115-
/O.CON.KPSR.FF.W.0079.000000T0000Z-210725T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1100 AM MST Sun Jul 25 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 215 PM MST THIS 
AFTERNOON FOR MARICOPA COUNTY...

At 1100 AM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 2 
and 3.5 inches of rain have fallen. The expected rainfall rate is 1 
to 2 inches in 1 hour. Additional rainfall amounts of 1 to 3 inches 
are possible in the warned area. Flash flooding is already 
occurring. Multiple water rescues have been reported in Sun City 
area. Standing water has also been observed on I-10 in Tolleson.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar and automated gauges.

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

Some locations that will experience flash flooding include...
  Phoenix, Glendale, Peoria, Surprise, Avondale, Goodyear, El 
  Mirage, Tolleson, Youngtown, Laveen, Sun City, Sun City West, 
  Glendale Sports Complex, Downtown Glendale, Camelback Ranch, 
  Downtown Peoria, Phoenix International Raceway, Arrowhead Mall, 
  South Phoenix and Komatke.

This includes the following highways...
	AZ Interstate 10 between mile markers 132 and 141.
	AZ Route 101 between mile markers 10 and 18.
	US Highway 60 between mile markers 141 and 150.

This includes the following streams and drainages...
  Agua Fria River, Corgett Wash, Cave Creek, Beardsley Canal, Salt 
  River, Gila River, New River, Skunk Creek and North Canyon Creek.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3329 11220 3331 11236 3336 11232 3359 11230
      3366 11238 3369 11236 3372 11221 3364 11216
      3351 11215 3343 11212 3337 11204 3329 11219

FLASH FLOOD...RADAR AND GAUGE INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

SDB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 10:57 PM MSTAreal Flood AdvisoryPSRMaricopa5 hr
Jul 25, 4:45 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 25, 6:27 AM MSTAreal Flood AdvisoryPSRPinal3 hr
Jul 25, 7:14 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 25, 7:38 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 25, 7:57 AM MSTAreal Flood AdvisoryPSRPinal3 hr
Jul 25, 8:01 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 25, 8:45 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal4 hr
Jul 25, 8:51 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Jul 25, 9:00 AM MSTFlash Flood Warning Considerable damage threatPSRPinal4 hr
Jul 25, 9:39 AM MSTAreal Flood AdvisoryPSRMaricopa17 min
Jul 25, 9:47 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal3 hr
Jul 25, 9:56 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa8 hr
Jul 25, 10:08 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa, Pinal4 hr
Jul 25, 10:41 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Jul 25, 12:11 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Jul 25, 12:35 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Jul 25, 12:54 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Jul 25, 2:10 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa4 hr
Jul 25, 2:14 PM MSTFlash Flood WarningPSRMaricopa3 hr
Jul 25, 2:18 PM MSTFlash Flood WarningPSRMaricopa3 hr
Jul 25, 3:29 PM MSTSpecial Weather StatementPSRLa Paz31 min
Jul 25, 4:02 PM MSTFlash Flood Warning Considerable damage threatPSRLa Paz4 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every flash flood warning in 2021

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.