Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 78, NWS Phoenix, AZ

July 25, 2021Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 25, 2021, 10:08 AM MST for Maricopa County, Pinal County, Arizona. It was in force for 4 hr. 1 report 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, 10:08 AM MST (17:08 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

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 66 km from the middle of the area, began a volume at 17:11 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, 11:35 AM MST	FLASH FLOOD	6 Nw Ak-Chin Village, AZ	HWY 238 CLOSED WEST OF MARICOPA.

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, 5.1 hours before the alert went out and 170 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.

543 
WGUS55 KPSR 251708
FFWPSR
AZC013-021-252115-
/O.NEW.KPSR.FF.W.0078.210725T1708Z-210725T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1008 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 215 PM MST.

* At 1008 AM 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. 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...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...
  Avondale, Goodyear, Buckeye, Gila Bend, Maricopa, Estrella 
  Sailport, Cotton Center, Rainbow Valley and Ak-Chin Village.

This includes the following highways...
	AZ Route 238 between mile markers 32 and 41.
	AZ Route 347 between mile markers 165 and 174.
	AZ Route 85 between mile markers 123 and 132.

This includes the following streams and drainages...
  Corgett Wash, Lum Wash, Waterman Wash, Gila River, Sauceda Wash, 
  Enterprise Canal, West Prong Waterman Wash and Rainbow Wash.

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 3316 11273 3331 11236 3329 11219 3323 11211
      3320 11208 3308 11191 3293 11203 3298 11220
      3299 11225 3308 11226 3303 11251 3297 11266
      3299 11272

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

$$

SDB

1 follow-up statement

760 
WGUS75 KPSR 252111
FFSPSR

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

AZC013-021-252121-
/O.EXP.KPSR.FF.W.0078.000000T0000Z-210725T2115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
211 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 215 PM MST THIS AFTERNOON FOR 
SOUTHWEST MARICOPA AND NORTHWEST 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 3316 11273 3331 11236 3329 11219 3323 11211
      3320 11208 3308 11191 3293 11203 3298 11220
      3299 11225 3308 11226 3303 11251 3297 11266
      3299 11272

$$

Iniguez

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, 8:45 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	4 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, 10:16 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.