Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 88, NWS Phoenix, AZ

July 25, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 25, 2021, 2:18 PM MST for Maricopa County, Arizona. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 25, 2021, 2:18 PM MST (21:18 UTC)
Expired: Jul 25, 2021, 4:57 PM MST
In force: 3 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
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 21:20 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.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 9.3 hours before the alert went out and 192 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.

357 
WGUS55 KPSR 252118
FFWPSR
AZC013-260015-
/O.NEW.KPSR.FF.W.0088.210725T2118Z-210726T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
218 PM 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 515 PM MST.

* At 218 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  2 and 3 inches of rain have fallen. Additional rainfall amounts up 
  to 1 inch are possible in the warned area. Flash flooding is 
  already occurring.

  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, Glendale, Peoria, Surprise, Avondale, El Mirage, 
  Tolleson, Youngtown, Sun City, Laveen, Sun City West, Glendale 
  Sports Complex, Downtown Glendale, Downtown Peoria, Camelback 
  Ranch, Arrowhead Mall and Phoenix International Raceway.

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, Beardsley Canal, Cave Creek, Salt River, Gila 
  River, North Canyon Creek, Skunk Creek and New River.

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 3333 11220 3334 11228 3336 11232 3359 11230
      3366 11238 3369 11236 3372 11221 3364 11216
      3351 11215 3343 11212 3339 11212 3337 11217

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Iniguez

1 follow-up statement

109 
WGUS75 KPSR 252357
FFSPSR

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

AZC013-260007-
/O.CAN.KPSR.FF.W.0088.000000T0000Z-210726T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
457 PM MST Sun Jul 25 2021

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

Flood waters have receded. 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 3333 11220 3334 11228 3336 11232 3359 11230
      3366 11238 3369 11236 3372 11221 3364 11216
      3351 11215 3343 11212 3339 11212 3337 11217

$$

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, 10:08 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, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.