Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 192, NWS Phoenix, AZ

August 16, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 16, 2021, 10:58 PM MST for Maricopa County, Arizona. It was in force for 7 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, 10:58 PM MST (05:58 UTC)
Expired: Aug 17, 2021, 5:59 AM MST
In force: 7 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 06:00 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, 6.0 hours before the alert went out and 69 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: 2667 J/kg
Mixed-layer CIN: -7 J/kg
Mixed-layer LCL: 1942 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: 24 m²/s²
0-3 km storm-relative helicity: 44 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

328 
WGUS55 KPSR 170558
FFWPSR
AZC013-171400-
/O.NEW.KPSR.FF.W.0192.210817T0558Z-210817T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1058 PM MST Mon Aug 16 2021

The National Weather Service in Phoenix has issued a

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

* Until 700 AM MST Tuesday.

* At 1058 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 2 inches of rain 
  have 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...
  mainly rural areas of Maricopa County

This includes the following streams and drainages...
  Verde River, East Fork Sycamore Creek, Sheep Creek, Sycamore 
  Creek, South Fork Sheep Creek, Davenport Wash and Copper Camp 
  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 3400 11149 3397 11147 3390 11149 3388 11151
      3388 11152 3386 11157 3388 11165 3391 11169
      3394 11169 3397 11167 3400 11166 3400 11158
      3400 11157 3400 11156 3400 11150

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

$$

Hirsch

1 follow-up statement

948 
WGUS75 KPSR 171259
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
559 AM MST Tue Aug 17 2021

AZC013-171309-
/O.CAN.KPSR.FF.W.0192.000000T0000Z-210817T1400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
559 AM MST Tue Aug 17 2021

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

Flood waters have receded near Sycamore Creek. The heavy rain has 
ended. Flooding is no longer expected to pose a threat. Please 
continue to heed remaining road closures.

LAT...LON 3400 11149 3397 11147 3390 11149 3388 11151
      3388 11152 3386 11157 3388 11165 3391 11169
      3394 11169 3397 11167 3400 11166 3400 11158
      3400 11157 3400 11156 3400 11150

$$

Hirsch

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 5:15 PM MST	Special Weather Statement	PSR	Gila	45 min
Aug 16, 5:46 PM MST	Special Weather Statement	PSR		44 min
Aug 16, 6:07 PM MST	Special Weather Statement	PSR	Gila	38 min
Aug 16, 6:14 PM MST	Severe Thunderstorm Warning	PSR	Gila	46 min
Aug 16, 6:37 PM MST	Special Weather Statement	PSR	Pinal	53 min
Aug 16, 6:55 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	6 hr
Aug 16, 8:24 PM MST	Special Weather Statement	PSR		51 min
Aug 16, 8:41 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	5 hr
Aug 16, 8:53 PM MST	Special Weather Statement	PSR	Gila	52 min
Aug 16, 9:08 PM MST	Special Weather Statement	PSR	Gila	52 min
Aug 16, 9:22 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa, Pinal	38 min
Aug 16, 9:41 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa, Pinal	49 min
Aug 16, 9:49 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Gila, Maricopa	41 min
Aug 16, 10:01 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 16, 10:01 PM MST	Special Weather Statement	PSR		44 min
Aug 16, 10:05 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 16, 10:14 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Gila, Maricopa, Pinal	46 min
Aug 16, 10:22 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	10 hr
Aug 16, 10:28 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa, Pinal	10 hr
Aug 16, 10:36 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	10 hr
Aug 16, 10:38 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	67 min
Aug 16, 10:48 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	9 hr
Aug 16, 10:54 PM MST	Severe Thunderstorm Warning Destructive damage threat	PSR	Maricopa, Pinal	51 min
Aug 16, 11:04 PM MST	Dust Storm Warning	PSR	Maricopa, Pinal	56 min
Aug 16, 11:07 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	7 hr
Aug 16, 11:16 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	7 hr
Aug 16, 11:26 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	8 hr
Aug 16, 11:31 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	44 min
Aug 16, 11:41 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Maricopa, Pinal	49 min
Aug 16, 11:47 PM MST	Dust Storm Warning	PSR	Maricopa	58 min
Aug 16, 11:50 PM MST	Special Weather Statement	PSR		40 min
Aug 16, 11:52 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	38 min
Aug 16, 11:56 PM MST	Flash Flood Warning Considerable damage threat	PSR	Pinal	7 hr
Aug 16, 11:59 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	6 hr
Aug 17, 12:01 AM MST	Dust Storm Warning	PSR	Maricopa, Pinal	59 min
Aug 17, 12:09 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	8 hr
Aug 17, 12:32 AM MST	Special Weather Statement	PSR		43 min
Aug 17, 12:36 AM MST	Special Weather Statement	PSR	Maricopa	24 min
Aug 17, 4:05 AM MST	Areal Flood Advisory	PSR	Maricopa	4 hr
Aug 17, 4:26 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	6 hr
Aug 17, 5:29 AM MST	Special Weather Statement	PSR	Maricopa	76 min
Aug 17, 5:35 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	6 hr
Aug 17, 6:26 AM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Pinal	5 hr
Aug 17, 8:42 AM MST	Areal Flood Warning	PSR	Gila	5 days
Aug 17, 4:46 PM MST	Special Weather Statement	PSR		44 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.