Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 14, NWS Phoenix, AZ

July 3, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 3, 2021, 6:05 PM MST for Maricopa County, Arizona. It was in force for 4 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 3, 2021, 6:05 PM MST (01:05 UTC)
Expired: Jul 3, 2021, 10:30 PM MST
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 74 km from the middle of the area, began a volume at 01:07 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, 1.1 hours before the alert went out and 62 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: 281 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 3054 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: 3 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

718 
WGUS55 KPSR 040105
FFWPSR
AZC013-040530-
/O.NEW.KPSR.FF.W.0014.210704T0105Z-210704T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
605 PM MST Sat Jul 3 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Maricopa County in south central Arizona...

* Until 1030 PM MST.

* At 605 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have fallen. 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...
  Lime Creek inflow to Horseshoe Reservoir 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3400 11172 3395 11164 3390 11164 3384 11173
      3387 11180 3401 11180 3400 11174 3400 11173

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

$$

MS

1 follow-up statement

643 
WGUS75 KPSR 040531
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1031 PM MST Sat Jul 3 2021

AZC013-040541-
/O.EXP.KPSR.FF.W.0014.000000T0000Z-210704T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1031 PM MST Sat Jul 3 2021

...FLASH FLOOD WARNING HAS EXPIRED FOR MARICOPA COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3400 11172 3395 11164 3390 11164 3384 11173
      3387 11180 3401 11180 3400 11174 3400 11173

$$

SDB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 3, 5:11 PM MST	Special Weather Statement	PSR		49 min
Jul 3, 5:20 PM MST	Special Weather Statement	PSR		25 min
Jul 3, 5:29 PM MST	Areal Flood Advisory	PSR	Pinal	3 hr
Jul 3, 5:32 PM MST	Special Weather Statement	PSR	Maricopa	43 min
Jul 3, 5:38 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Jul 3, 5:41 PM MST	Dust Storm Warning	PSR	Maricopa, Pinal	44 min
Jul 3, 5:43 PM MST	Dust Storm Warning	PSR	Maricopa	62 min
Jul 3, 5:56 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 3, 6:10 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 3, 6:20 PM MST	Special Weather Statement	PSR	Maricopa	40 min
Jul 3, 6:23 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	4 hr
Jul 3, 6:31 PM MST	Special Weather Statement	PSR	Gila	44 min
Jul 3, 6:43 PM MST	Dust Storm Warning	PSR	La Paz, Maricopa, Pinal, Yuma	62 min
Jul 3, 6:46 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	4 hr
Jul 3, 7:13 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 4, 3:09 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Jul 4, 3:43 PM MST	Special Weather Statement	PSR	Gila	32 min
Jul 4, 4:10 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Jul 4, 4:36 PM MST	Special Weather Statement	PSR	Gila	24 min
Jul 4, 4:51 PM MST	Special Weather Statement	PSR	Gila	39 min

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.