Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 74, NWS Phoenix, AZ

July 25, 2021Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 25, 2021, 8:45 AM MST for Maricopa County, Pinal County, Arizona. It was in force for 4 hr. 2 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, 8:45 AM MST (15:45 UTC)
Expired: Jul 25, 2021, 12:45 PM MST
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 73 km from the middle of the area, began a volume at 15:45 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

Time	Report	Where	Remark
Jul 25, 8:53 AM MST	FLASH FLOOD	8 Ssw Ak-Chin Village, AZ	MULTIPLE RUNNING WASHES REPORTED WITH 6-12 INCHES OF RUNNING WATER OVER WARREN RD IN MULTIPLE LOCATIONS.
Jul 25, 11:35 AM MST	FLASH FLOOD	7 Wsw Mobile, AZ	HWY 238 CLOSED BETWEEN MPS 14 AND 38.

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, 3.8 hours before the alert went out and 157 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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.

926 
WGUS55 KPSR 251545
FFWPSR
AZC013-021-251945-
/O.NEW.KPSR.FF.W.0074.210725T1545Z-210725T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
845 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...
  Pinal County in southeastern Arizona...

* Until 1245 PM MST.

* At 845 AM MST, Doppler radar indicated heavy rain across the 
  warned area. Between 1 and 2 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. Heavy rain 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...
  Gila Bend, Estrella, Freeman, Big Horn, Sonoran National Monument, 
  Bosque and Stanfield.

This includes the following highways...
	AZ Route 238 between mile markers 10 and 19.
	AZ Route 347 between mile markers 161 and 164.
	AZ Interstate 8 between mile markers 122 and 131.

This includes the following streams and drainages...
  Sand Tank Wash, Vekol Wash, Waterman Wash, Sauceda Wash, Bender 
  Wash, Gila River and West Prong Waterman Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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 3281 11233 3290 11263 3297 11266 3302 11255
      3307 11228 3299 11225 3289 11193 3280 11192

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

$$

SDB

2 follow-up statements

792 
WGUS75 KPSR 251625
FFSPSR

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

AZC013-021-251945-
/O.CON.KPSR.FF.W.0074.000000T0000Z-210725T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
925 AM MST Sun Jul 25 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1245 PM MST THIS 
AFTERNOON FOR MARICOPA AND PINAL COUNTIES...

At 925 AM MST, the public reported heavy rain across the warned 
area. Between 1.5 and 2.5 inches of rain have fallen. Additional 
rainfall amounts of 1 to 2 inches are possible in the warned area. 
Flash flooding is already occurring. Multiple washes are running 
between I-8 and the town of Maricopa with 6-12 inches of water 
flowing over roads.

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

SOURCE...Public reported.

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

Some locations that will experience flash flooding include...
  Gila Bend, Estrella, Freeman, Big Horn, Sonoran National Monument, 
  Bosque and Stanfield.

This includes the following highways...
	AZ Route 238 between mile markers 10 and 19.
	AZ Route 347 between mile markers 161 and 164.
	AZ Interstate 8 between mile markers 122 and 131.

This includes the following streams and drainages...
  Sand Tank Wash, Vekol Wash, Waterman Wash, Sauceda Wash, Bender 
  Wash, Gila River and West Prong Waterman Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

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 3281 11233 3290 11263 3297 11266 3302 11255
      3307 11228 3299 11225 3289 11193 3280 11192

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

$$

SDB

520 
WGUS75 KPSR 251939
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1239 PM MST Sun Jul 25 2021

AZC013-021-251949-
/O.EXP.KPSR.FF.W.0074.000000T0000Z-210725T1945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
1239 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1245 PM MST THIS AFTERNOON FOR 
MARICOPA AND PINAL COUNTIES...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. 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 3281 11233 3290 11263 3297 11266 3302 11255
      3307 11228 3299 11225 3289 11193 3280 11192

$$

MS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 24, 10:57 PM MST	Areal Flood Advisory	PSR	Maricopa	5 hr
Jul 25, 4:45 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 25, 6:27 AM MST	Areal Flood Advisory	PSR	Pinal	3 hr
Jul 25, 7:14 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 25, 7:38 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 25, 7:57 AM MST	Areal Flood Advisory	PSR	Pinal	3 hr
Jul 25, 8:01 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 25, 8:51 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	6 hr
Jul 25, 9:00 AM MST	Flash Flood Warning Considerable damage threat	PSR	Pinal	4 hr
Jul 25, 9:39 AM MST	Areal Flood Advisory	PSR	Maricopa	17 min
Jul 25, 9:47 AM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Jul 25, 9:56 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	8 hr
Jul 25, 10:08 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	4 hr
Jul 25, 10:16 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 25, 10:41 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 25, 12:11 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Jul 25, 12:35 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 25, 12:54 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 25, 2:10 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	4 hr
Jul 25, 2:14 PM MST	Flash Flood Warning	PSR	Maricopa	3 hr
Jul 25, 2:18 PM MST	Flash Flood Warning	PSR	Maricopa	3 hr
Jul 25, 3:29 PM MST	Special Weather Statement	PSR	La Paz	31 min
Jul 25, 4:02 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr

Nearby

Flash Flood Warnings in Arizona, 2021 Every 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.