Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 18, NWS Phoenix, AZ

July 3, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 3, 2021, 7:13 PM MST for Maricopa 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 3, 2021, 7:13 PM MST (02:13 UTC)
Expired: Jul 3, 2021, 11:15 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), 41 km from the middle of the area, began a volume at 02:16 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 3, 7:30 PM MST	FLASH FLOOD	1 Nne Saguaro Lake, AZ	DELAYED REPORT BUTCHER JONES BEACH RD WAS CLOSED DUE TO SIGNIFICANT FLASH FLOODING ACROSS ROADWAY, CUTTING OFF ACCESS TO BUTCHER JONES RECREATION AREA. TIME ESTIMATED BY RADAR.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 2.2 hours before the alert went out and 50 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.

899 
WGUS55 KPSR 040213
FFWPSR
AZC013-040615-
/O.NEW.KPSR.FF.W.0018.210704T0213Z-210704T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  The Bush burn scar in...
  Maricopa County in south central Arizona...

* Until 1115 PM MST.

* At 713 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Bush Burn Scar. Between 1 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 rises along 
Cottonwood Creek and its tributary streams.

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

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  Saguaro Lake and Salt River Tubing Recreation Area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3368 11151 3372 11138 3356 11141 3354 11147
      3355 11162

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

$$

MS

1 follow-up statement

351 
WGUS75 KPSR 040613
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1113 PM MST Sat Jul 3 2021

AZC013-040623-
/O.EXP.KPSR.FF.W.0018.000000T0000Z-210704T0615Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1113 PM MST Sat Jul 3 2021

...FLASH FLOOD WARNING FOR THE BUSH BURN SCAR WILL EXPIRE AT 1115 PM 
MST THIS EVENING 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 3368 11151 3372 11138 3356 11141 3354 11147
      3355 11162

$$

CK

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, 6:05 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 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 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.