Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 71, NWS Phoenix, AZ

July 23, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 23, 2021, 1:11 PM MST for Maricopa County, Arizona. It was in force for 5 hr. 6 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 23, 2021, 1:11 PM MST (20:11 UTC)
Expired
Jul 23, 2021, 6:15 PM MST
In force
5 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), 72 km from the middle of the area, began a volume at 20:12 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 23, 1:35 PM MSTFLASH FLOOD6 W Cave Creek, AZDELAYED REPORT. TWO MEN WERE RESCUED BY MCSO HELICOPTER FROM THE TOP OF THEIR STRANDED FOOD DELIVERY TRUCK WHICH WAS STUCK IN A FLOODED WASH ON CLOUD ROAD NEAR 7TH ST.
Jul 23, 2:23 PM MSTFLASH FLOOD6 Sse New River, AZFCDMC GAUGE 64807 SKUNK CREEK ALONG DESERT HILLS DR. AND CLOSE TO N. 15TH AVE. EXCEEDED ALARM STAGE AND BANK FULL STAGE.
Jul 23, 2:23 PM MSTFLASH FLOOD6 Wsw Cave Creek, AZONE VEHICLE REPORTED STRANDED WITH RESCUE REQUIRED BY LAW ENFORCEMENT OFF CAREFREE HWY. AND N. 12TH ST. DUE TO FLOWING WATER ON N. 12TH ST.
Jul 23, 2:23 PM MSTFLASH FLOOD6 Wsw Cave Creek, AZSOCIAL MEDIA POST SHOWS FLOWING WATER ACROSS 10TH ST. JUST SOUTH OF CAREFREE HWY. NEAR EAST FORK DESERT LAKE WASH.
Jul 23, 6:05 PM MSTFLASH FLOOD6 Sse New River, AZ*** DELAYED REPORT *** MCDOT TWITTER REPORTS 19TH AVE. CLOSED FROM DESERT HILLS DR. TO IRVINE RD. DUE TO FLOODING.
Jul 23, 6:05 PM MSTFLASH FLOOD7 S New River, AZ*** DELAYED REPORT *** MCDOT TWITTER REPORTS ROAD CLOSURE OF 27TH AVE. FROM CLOUD RD. TO DOLORES RD. DUE TO FLOODING.

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

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.2 hours before the alert went out and 154 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, Flgstf/Belemont, AZ at 12:00Z on 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 503 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
503 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

026 
WGUS55 KPSR 232011
FFWPSR
AZC013-240015-
/O.NEW.KPSR.FF.W.0071.210723T2011Z-210724T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
111 PM MST Fri Jul 23 2021

The National Weather Service in Phoenix has issued a

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

* Until 515 PM MST.

* At 111 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...Life threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Phoenix, Scottsdale, New River, Cave Creek and Carefree.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3389 11212 3388 11211 3388 11207 3388 11197
      3394 11192 3376 11188 3376 11209 3382 11214

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

$$

MS
2 follow-up statements
434 
WGUS55 KPSR 232344
FFWPSR
AZC013-240115-
/O.EXT.KPSR.FF.W.0071.000000T0000Z-210724T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
444 PM MST Fri Jul 23 2021

The National Weather Service in Phoenix has extended the

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

* Until 615 PM MST.

* At 444 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 already occurring in some spots. 
  Runoff will continue and new impacts are possible.

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

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Phoenix, Scottsdale, New River, Cave Creek and Carefree.

Avoid any flooded roads. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3389 11212 3388 11211 3388 11207 3388 11197
      3394 11192 3376 11188 3376 11209 3382 11214

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

$$

AD
551 
WGUS75 KPSR 240119
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
619 PM MST Fri Jul 23 2021

AZC013-240129-
/O.EXP.KPSR.FF.W.0071.000000T0000Z-210724T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
619 PM MST Fri Jul 23 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR MARICOPA COUNTY...

The Flash Flood Warning has been replaced by an Areal Flood Warning. 
Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for a 
portion of south central Arizona.

LAT...LON 3389 11212 3388 11211 3388 11207 3388 11197
      3394 11192 3376 11188 3376 11209 3382 11214

$$

AD

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 5:42 PM MSTSpecial Weather StatementPSR48 min
Jul 22, 6:11 PM MSTAreal Flood AdvisoryPSRMaricopa39 min
Jul 22, 6:31 PM MSTSpecial Weather StatementPSR59 min
Jul 22, 6:50 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Jul 22, 7:19 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 22, 7:29 PM MSTSpecial Weather StatementPSR61 min
Jul 22, 7:40 PM MSTSevere Thunderstorm WarningPSRPinal35 min
Jul 22, 7:46 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa5 hr
Jul 22, 7:48 PM MSTDust Storm AdvisoryPSRMaricopa, Pinal27 min
Jul 22, 7:53 PM MSTSpecial Weather StatementPSRPinal37 min
Jul 22, 7:55 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal5 hr
Jul 22, 8:05 PM MSTSpecial Weather StatementPSRMaricopa25 min
Jul 22, 8:06 PM MSTFlash Flood Warning Considerable damage threatPSRPinal4 hr
Jul 22, 8:15 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 22, 8:19 PM MSTSevere Thunderstorm WarningPSRMaricopa26 min
Jul 22, 8:29 PM MSTSpecial Weather StatementPSRPinal61 min
Jul 22, 8:39 PM MSTSpecial Weather StatementPSRMaricopa51 min
Jul 22, 8:52 PM MSTFlash Flood WarningPSRMaricopa4 hr
Jul 22, 8:56 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 22, 9:28 PM MSTSpecial Weather StatementPSRMaricopa47 min
Jul 22, 9:40 PM MSTFlash Flood WarningPSRMaricopa3 hr
Jul 22, 9:45 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa3 hr
Jul 22, 9:49 PM MSTFlash Flood WarningPSRMaricopa4 hr
Jul 22, 9:54 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa4 hr
Jul 22, 10:07 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa, Pinal4 hr
Jul 22, 10:16 PM MSTAreal Flood AdvisoryPSRPinal3 hr
Jul 22, 10:57 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa113 min
Jul 22, 11:15 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Jul 22, 11:29 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Jul 22, 11:43 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Jul 23, 4:37 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 23, 8:37 AM MSTAreal Flood WarningPSRGila4 days
Jul 23, 9:07 AM MSTSpecial Weather StatementPSR38 min
Jul 23, 9:30 AM MSTSpecial Weather StatementPSR30 min
Jul 23, 9:55 AM MSTAreal Flood WarningPSRMaricopa6 hr
Jul 23, 9:58 AM MSTSpecial Weather StatementPSR32 min
Jul 23, 10:31 AM MSTSpecial Weather StatementPSR29 min
Jul 23, 10:53 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Jul 23, 11:11 AM MSTSpecial Weather StatementPSR34 min
Jul 23, 11:46 AM MSTSpecial Weather StatementPSR29 min
Jul 23, 12:02 PM MSTSpecial Weather StatementPSR28 min
Jul 23, 12:09 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Jul 23, 12:30 PM MSTSpecial Weather StatementPSR30 min
Jul 23, 12:53 PM MSTSpecial Weather StatementPSR37 min
Jul 23, 1:01 PM MSTSpecial Weather StatementPSR29 min
Jul 23, 1:34 PM MSTSpecial Weather StatementPSR26 min
Jul 23, 2:25 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Jul 23, 3:20 PM MSTAreal Flood WarningPSRMaricopa9 hr
Jul 23, 4:00 PM MSTAreal Flood WarningPSRMaricopa8 hr
Jul 23, 4:02 PM MSTAreal Flood WarningPSRMaricopa8 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.