Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 181, NWS Phoenix, AZ

August 15, 2021Gila County, Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 15, 2021, 10:50 PM MST for Gila County, Maricopa County, Pinal 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 15, 2021, 10:50 PM MST (05:50 UTC)
Expired: Aug 16, 2021, 4:43 AM MST
In force: 6 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Gila County, AZ, Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 64 km from the middle of the area, began a volume at 05:53 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.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 5.8 hours before the alert went out and 85 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: 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.

720 
WGUS55 KPSR 160550
FFWPSR
AZC007-013-021-161000-
/O.NEW.KPSR.FF.W.0181.210816T0550Z-210816T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1050 PM MST Sun Aug 15 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  The Woodbury Burn Scar in...
  Gila County in east central Arizona...
  Maricopa County in south central Arizona...
  Pinal County in southeastern Arizona...

* Until 300 AM MST.

* At 1050 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Woodbury Burn Scar. Between 0.5 and 1.5 inches 
  of rain have fallen. Flash flooding is ongoing or expected to 
  begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Campaign Creek. The debris flow can consist of 
rock, mud, vegetation and other loose materials.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Woodbury
           Burn Scar.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Woodbury Burn Scar.

* Some locations that will experience flash flooding include...
  Roosevelt Estates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3355 11116 3359 11109 3366 11107 3365 11105
      3366 11101 3363 11098 3360 11100 3354 11102
      3346 11102 3345 11118

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

$$

CK

3 follow-up statements

811 
WGUS75 KPSR 160642
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1142 PM MST Sun Aug 15 2021

AZC007-013-021-161000-
/O.CON.KPSR.FF.W.0181.000000T0000Z-210816T1000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Maricopa AZ-Pinal AZ-
1142 PM MST Sun Aug 15 2021

...FLASH FLOOD WARNING FOR THE WOODBURY BURN SCAR REMAINS IN EFFECT 
UNTIL 3 AM MST MONDAY FOR GILA, MARICOPA AND PINAL COUNTIES...

At 1142 PM MST, Doppler radar indicated thunderstorms produced heavy 
rain over the Woodbury Burn Scar. Between 0.5 and 1.5 inches of rain 
have fallen. Flash flooding is ongoing or expected to begin shortly.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Campaign Creek. The debris flow can consist of 
rock, mud, vegetation and other loose materials.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding in and around the Woodbury Burn Scar.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of areas in and around
         the Woodbury Burn Scar.

Some locations that will experience flash flooding include...
  Roosevelt Estates.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3355 11116 3359 11109 3366 11107 3365 11105
      3366 11101 3363 11098 3360 11100 3354 11102
      3346 11102 3345 11118

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

$$

CK

454 
WGUS55 KPSR 160947
FFWPSR
AZC007-013-021-161200-
/O.EXT.KPSR.FF.W.0181.000000T0000Z-210816T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Phoenix has extended the

* Flash Flood Warning for...
  The Woodbury Burn Scar in...
  Gila County in east central Arizona...
  Maricopa County in south central Arizona...
  Pinal County in southeastern Arizona...

* Until 500 AM MST.

* At 247 AM MST, Doppler radar indicated thunderstorms produced 
  heavy rain over the Woodbury Burn Scar. Between 0.5 and 1.5 inches 
  of rain have fallen. Flash flooding may still be occurring.

Excessive rainfall over the burn scar will result in debris flow 
moving through the Campaign Creek. The debris flow can consist of 
rock, mud, vegetation and other loose materials.

  HAZARD...Life threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Woodbury
           Burn Scar.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of areas in and around
           the Woodbury Burn Scar.

* Some locations that will experience flash flooding include...
  Roosevelt Estates.

This includes the following streams and drainages...
  Campaign Creek, Reavis Creek, Barranca Creek and Pine Creek.

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 3355 11116 3359 11109 3366 11107 3365 11105
      3366 11101 3363 11098 3360 11100 3354 11102
      3346 11102 3345 11118

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

$$

Hirsch

548 
WGUS75 KPSR 161143
FFSPSR

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

AZC007-013-021-161153-
/O.CAN.KPSR.FF.W.0181.000000T0000Z-210816T1200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Maricopa AZ-Pinal AZ-
443 AM MST Mon Aug 16 2021

...FLASH FLOOD WARNING FOR THE WOODBURY BURN SCAR IS CANCELLED FOR 
GILA, MARICOPA AND PINAL COUNTIES...

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 200 AM MST Tuesday for a 
portion of south central Arizona.

LAT...LON 3355 11116 3359 11109 3366 11107 3365 11105
      3366 11101 3363 11098 3360 11100 3354 11102
      3346 11102 3345 11118

$$

Hirsch

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 15, 7:49 PM MST	Special Weather Statement	PSR	Gila	56 min
Aug 15, 8:26 PM MST	Severe Thunderstorm Warning	PSR	Gila	49 min
Aug 15, 9:14 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa, Pinal	46 min
Aug 15, 9:18 PM MST	Special Weather Statement	PSR	Gila	42 min
Aug 15, 9:58 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Gila, Maricopa, Pinal	47 min
Aug 15, 10:14 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 15, 10:31 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	44 min
Aug 15, 10:45 PM MST	Special Weather Statement	PSR	Pinal	45 min
Aug 15, 10:55 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	65 min
Aug 15, 10:58 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Aug 15, 11:14 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	46 min
Aug 15, 11:31 PM MST	Special Weather Statement	PSR	Maricopa	44 min
Aug 15, 11:37 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	38 min
Aug 15, 11:44 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	32 min
Aug 15, 11:45 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 16, 12:18 AM MST	Special Weather Statement	PSR		42 min
Aug 16, 12:49 AM MST	Severe Thunderstorm Warning	PSR	La Paz, Maricopa	56 min
Aug 16, 1:33 AM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Maricopa	6 hr
Aug 16, 1:47 AM MST	Special Weather Statement	PSR	La Paz	58 min
Aug 16, 1:54 AM MST	Severe Thunderstorm Warning	PSR	La Paz	66 min
Aug 16, 2:22 AM MST	Special Weather Statement	PSR	La Paz	68 min
Aug 16, 2:53 AM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	5 hr
Aug 16, 3:08 AM MST	Dust Storm Advisory	PSR	La Paz, Yuma	2 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.