Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 182, NWS Phoenix, AZ

August 16, 2021La Paz County, Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 16, 2021, 1:33 AM MST for La Paz County, Maricopa County, Arizona. It was in force for 6 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
Aug 16, 2021, 1:33 AM MST (08:33 UTC)
Expired
Aug 16, 2021, 7:30 AM MST
In force
6 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties La Paz County, AZ, Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 182 km from the middle of the area, began a volume at 08:36 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

Phoenix, AZ (KPSR), launched 00:00Z, 8.6 hours before the alert went out and 150 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 2021-08-16Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1548 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 2021-08-16The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
1548 J/kg
Mixed-layer CIN
-94 J/kg
Mixed-layer LCL
2123 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
56 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

067 
WGUS55 KPSR 160833
FFWPSR
AZC012-013-161430-
/O.NEW.KPSR.FF.W.0182.210816T0833Z-210816T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
133 AM MST Mon Aug 16 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Maricopa County in south central Arizona...
  Northeastern La Paz County in west central Arizona...

* Until 730 AM MST.

* At 133 AM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1 inch of rain 
  has fallen. Additional rainfall amounts of 0.5 to 1 inch 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.

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

* Some locations that will experience flash flooding include...
  Wenden, Salome, Gladden, Harcuvar, Vicksburg, Vicksburg Junction, 
  Aguila, Alamo Lake State Park and Bouse.

This includes the following highways...
	AZ Route 72 between mile markers 27 and 36.
	US Highway 60 between mile markers 100 and 103...and
	between mile markers 39 and 44.

This includes the following streams and drainages...
  Browns Canyon Wash, Powerline Wash, Alamo Wash, Date Creek, 
  Calcite Wash, Bullard Wash, Tiger Wash, Pump Mine Wash, Sols Wash, 
  Cunningham Wash, Jackrabbit Wash, Bouse Wash, Bill Williams River, 
  Centennial Wash, Grass Wash, Santa Maria River, Salome Wash and 
  Dead Horse Wash.

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.

&&

LAT...LON 3431 11352 3429 11337 3432 11333 3400 11333
      3400 11281 3378 11300 3367 11325 3362 11343
      3366 11386 3386 11404 3399 11398

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

$$

Hirsch
2 follow-up statements
256 
WGUS75 KPSR 160949
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
249 AM MST Mon Aug 16 2021

AZC012-013-161430-
/O.CON.KPSR.FF.W.0182.000000T0000Z-210816T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-Maricopa AZ-
249 AM MST Mon Aug 16 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 AM MST THIS 
MORNING FOR MARICOPA AND NORTHEASTERN LA PAZ COUNTIES...

At 249 AM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 0.5 and 1 inch of rain has 
fallen. Additional rainfall amounts up to 0.5 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.

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

Some locations that will experience flash flooding include...
  Wenden, Salome, Gladden, Harcuvar, Vicksburg, Vicksburg Junction, 
  Aguila, Alamo Lake State Park and Bouse.

This includes the following highways...
	AZ Route 72 between mile markers 27 and 36.
	US Highway 60 between mile markers 100 and 103...and
	between mile markers 39 and 44.

This includes the following streams and drainages...
  Browns Canyon Wash, Powerline Wash, Alamo Wash, Date Creek, 
  Calcite Wash, Bullard Wash, Tiger Wash, Pump Mine Wash, Sols Wash, 
  Cunningham Wash, Jackrabbit Wash, Bouse Wash, Bill Williams River, 
  Centennial Wash, Grass Wash, Santa Maria River, Salome Wash and 
  Dead Horse Wash.

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.

&&

LAT...LON 3431 11352 3429 11337 3432 11333 3400 11333
      3400 11281 3378 11300 3367 11325 3362 11343
      3366 11386 3386 11404 3399 11398

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

$$

Hirsch
614 
WGUS75 KPSR 161437
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
737 AM MST Mon Aug 16 2021

AZC012-013-161447-
/O.EXP.KPSR.FF.W.0182.000000T0000Z-210816T1430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-Maricopa AZ-
737 AM MST Mon Aug 16 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR MARICOPA AND NORTHEASTERN LA 
PAZ 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 200 AM MST Tuesday for a 
portion of south central Arizona.

LAT...LON 3431 11352 3429 11337 3432 11333 3400 11333
      3400 11281 3378 11300 3367 11325 3362 11343
      3366 11386 3386 11404 3399 11398

$$

INS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 15, 7:49 PM MSTSpecial Weather StatementPSRGila56 min
Aug 15, 8:26 PM MSTSevere Thunderstorm WarningPSRGila49 min
Aug 15, 9:14 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa, Pinal46 min
Aug 15, 9:18 PM MSTSpecial Weather StatementPSRGila42 min
Aug 15, 9:58 PM MSTSevere Thunderstorm Warning Considerable damage threatPSRGila, Maricopa, Pinal47 min
Aug 15, 10:14 PM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 15, 10:31 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal44 min
Aug 15, 10:45 PM MSTSpecial Weather StatementPSRPinal45 min
Aug 15, 10:50 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa, Pinal6 hr
Aug 15, 10:55 PM MSTDust Storm AdvisoryPSRMaricopa, Pinal65 min
Aug 15, 10:58 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal3 hr
Aug 15, 11:14 PM MSTSevere Thunderstorm WarningPSRMaricopa46 min
Aug 15, 11:31 PM MSTSpecial Weather StatementPSRMaricopa44 min
Aug 15, 11:37 PM MSTSevere Thunderstorm WarningPSRMaricopa38 min
Aug 15, 11:44 PM MSTSevere Thunderstorm WarningPSRMaricopa32 min
Aug 15, 11:45 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Aug 16, 12:18 AM MSTSpecial Weather StatementPSR42 min
Aug 16, 12:49 AM MSTSevere Thunderstorm WarningPSRLa Paz, Maricopa56 min
Aug 16, 1:47 AM MSTSpecial Weather StatementPSRLa Paz58 min
Aug 16, 1:54 AM MSTSevere Thunderstorm WarningPSRLa Paz66 min
Aug 16, 2:22 AM MSTSpecial Weather StatementPSRLa Paz68 min
Aug 16, 2:53 AM MSTFlash Flood Warning Considerable damage threatPSRLa Paz5 hr
Aug 16, 3:08 AM MSTDust Storm AdvisoryPSRLa Paz, Yuma2 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.