Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 59, NWS Phoenix, AZ

July 22, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 22, 2021, 8:52 PM MST for Maricopa County, Arizona. It was in force for 4 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 22, 2021, 8:52 PM MST (03:52 UTC)
Expired
Jul 23, 2021, 12:49 AM MST
In force
4 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 49 km from the middle of the area, began a volume at 03:53 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 22, 9:10 PM MSTHEAVY RAIN 0.753 Wsw Fountain Hills, AZOBSERVED IN 30 MINUTES. ESTIMATED WINDS 50 MPH.
Jul 22, 9:24 PM MSTFLASH FLOOD1 Ese Paradise Valley, AZCURB TO CURB STREET FLOODING REPORTED.
Jul 22, 10:00 PM MSTFLASH FLOOD1 Se Scottsdale, AZTIM APPROX: MEDIA REPORTED A VEHICLE STUCK IN FLOWING WATER ON A SUBMERGED ROAD. DRIVER WAS RESCUED BY FIRE DEPARTMENT.
Jul 22, 10:14 PM MSTFLASH FLOOD4 S Deer Valley, AZVEHICLE TRAPPED IN FLOOD WATER AT I17/THUNDERBIRD. PORTIONS OF THE ROAD AND HIGHWAY WERE CLOSED DUE TO FLOODING.
Jul 22, 10:21 PM MSTFLASH FLOOD3 S Deer Valley, AZADOT REPORTED HIGHWAY RAMPS AT I17/GREENWAY WERE COMPLETELY UNDERWATER.
Jul 22, 10:30 PM MSTFLASH FLOOD1 Ene Scottsdale, AZNUMEROUS REPORTS OF SWIFT RUNNING WATER INUNDATING MANY PLACES ALONG INDIAN BEND WASH. PICTURES SHOW WATER DEPTH AT LEAST 6 INCHES IN MANY SPOTS.

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

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 3.9 hours before the alert went out and 23 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 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1155 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, Phoenix, AZ at 00:00Z on 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 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
1155 J/kg
Mixed-layer CIN
-46 J/kg
Mixed-layer LCL
2803 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
-22 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

242 
WGUS55 KPSR 230352
FFWPSR
AZC013-230800-
/O.NEW.KPSR.FF.W.0059.210723T0352Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
852 PM MST Thu Jul 22 2021

The National Weather Service in Phoenix has issued a

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

* Until 100 AM MST.

* At 852 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  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...
  Phoenix, Mesa, Glendale, Scottsdale, Tempe, Paradise Valley, 
  Piestewa Peak Park, Camelback Mountain, Scottsdale Airport, Desert 
  Ridge Marketplace, North Mountain Park, Downtown Scottsdale, 
  Papago Park, Salt River Indian Community, Metro Center Mall, Sky 
  Harbor Airport, Deer Valley Airport, Tempe Marketplace, Arizona 
  State University and Arizona State Fairgrounds.

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.

&&

LAT...LON 3360 11223 3372 11206 3373 11202 3378 11190
      3376 11185 3350 11175 3338 11201

FLASH FLOOD...RADAR INDICATED

$$

AD
5 follow-up statements
802 
WGUS75 KPSR 230407
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
907 PM MST Thu Jul 22 2021

AZC013-230800-
/O.CON.KPSR.FF.W.0059.000000T0000Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
907 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM MST FRIDAY FOR 
MARICOPA COUNTY...

At 907 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
0.5 and 1 inch of rain has fallen. Flash flooding is ongoing or 
expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

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...
  Phoenix, Mesa, Glendale, Scottsdale, Tempe, Paradise Valley, 
  Piestewa Peak Park, Camelback Mountain, Scottsdale Airport, Desert 
  Ridge Marketplace, North Mountain Park, Downtown Scottsdale, 
  Papago Park, Salt River Indian Community, Metro Center Mall, Sky 
  Harbor Airport, Deer Valley Airport, Tempe Marketplace, Arizona 
  State University and Arizona State Fairgrounds.

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.

&&

LAT...LON 3360 11223 3372 11206 3373 11202 3378 11190
      3376 11185 3350 11175 3338 11201

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

AD
743 
WGUS75 KPSR 230421
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
921 PM MST Thu Jul 22 2021

AZC013-230800-
/O.CON.KPSR.FF.W.0059.000000T0000Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
921 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM MST FRIDAY FOR 
MARICOPA COUNTY...

At 921 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 
0.5 and 1 inch of rain has fallen. 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, Mesa, Glendale, Scottsdale, Tempe, Paradise Valley, 
  Piestewa Peak Park, Camelback Mountain, Scottsdale Airport, Desert 
  Ridge Marketplace, North Mountain Park, Downtown Scottsdale, 
  Papago Park, Salt River Indian Community, Metro Center Mall, Sky 
  Harbor Airport, Deer Valley Airport, Tempe Marketplace, Arizona 
  State University and Arizona State Fairgrounds.

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.

&&

LAT...LON 3360 11223 3372 11206 3373 11202 3378 11190
      3376 11185 3350 11175 3338 11201

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

$$

AD
805 
WGUS75 KPSR 230431
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
931 PM MST Thu Jul 22 2021

AZC013-230800-
/O.CON.KPSR.FF.W.0059.000000T0000Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
931 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM MST FRIDAY FOR 
MARICOPA COUNTY...

At 931 PM 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. 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, Mesa, Scottsdale, Tempe, Paradise Valley, Scottsdale 
  Airport, Camelback Mountain, Downtown Scottsdale, Piestewa Peak 
  Park, Desert Ridge Marketplace, Salt River Indian Community, 
  Papago Park, North Mountain Park, Tempe Marketplace, Arizona State 
  University and Sky Harbor Airport.

Low water crossings and normally dry washes will contain storm 
runoff. Locations like Reata Pass Wash, Indian Bend Wash, Old 
Crosscut Canal at McDowell, and Granite Reef Wash are experiencing 
flooding.

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.

&&

LAT...LON 3357 11209 3360 11206 3362 11205 3367 11204
      3371 11204 3373 11202 3378 11190 3376 11185
      3350 11175 3338 11201 3349 11207

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

$$

AD
026 
WGUS75 KPSR 230501
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1001 PM MST Thu Jul 22 2021

AZC013-230800-
/O.CON.KPSR.FF.W.0059.000000T0000Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1001 PM MST Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1 AM MST FRIDAY FOR 
MARICOPA COUNTY...

At 1001 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain across the warned area. Between 1 
and 2 inches of rain have fallen. Flash flooding is occurring.

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, Mesa, Scottsdale, Tempe, Paradise Valley, Scottsdale 
  Airport, Camelback Mountain, Downtown Scottsdale, Piestewa Peak 
  Park, Desert Ridge Marketplace, Salt River Indian Community, 
  Papago Park, North Mountain Park, Tempe Marketplace, Arizona State 
  University and Sky Harbor Airport.

Maricopa County Flood Control gauge at Granite Reef Wash, near 
Granite Reef Rd and McDowell, has reached flood stage. Multiple 
county gauges along Indian Bend Wash also continue to rise.

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.

&&

LAT...LON 3357 11209 3360 11206 3362 11205 3367 11204
      3371 11204 3373 11202 3378 11190 3376 11185
      3350 11175 3338 11201 3349 11207

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

$$

AD
978 
WGUS75 KPSR 230749
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1249 AM MST Fri Jul 23 2021

AZC013-230759-
/O.CAN.KPSR.FF.W.0059.000000T0000Z-210723T0800Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1249 AM MST Fri Jul 23 2021

...FLASH FLOOD WARNING IS CANCELLED FOR MARICOPA COUNTY...

The heavy rain has ended and flood waters are receding. New flooding 
is no longer expected to pose a threat. Please continue to heed 
remaining road closures and avoid any areas that have lingering 
flooding.

A Flash Flood Watch remains in effect until 1100 PM MST Saturday for 
a portion of south central Arizona.

LAT...LON 3347 11193 3351 11194 3354 11193 3354 11188
      3344 11189 3343 11191 3344 11192 3344 11193

$$

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, 8:56 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, 1:11 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa5 hr
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.