Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 224, NWS Phoenix, AZ

August 18, 2021Gila County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 18, 2021, 5:39 PM MST for Gila 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: Aug 18, 2021, 5:39 PM MST (00:39 UTC)
Expired: Aug 18, 2021, 9:45 PM MST
In force: 4 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Gila County, AZ

The radar

The Phoenix radar (KIWA), 94 km from the middle of the area, began a volume at 00:39 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, 0.7 hours before the alert went out and 123 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: 510 J/kg
Mixed-layer CIN: -174 J/kg
Mixed-layer LCL: 1692 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 157 m²/s²
0-3 km storm-relative helicity: 230 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.7

Open this sounding in Storm Lab

The text

As transmitted.

583 
WGUS55 KPSR 190039
FFWPSR
AZC007-190445-
/O.NEW.KPSR.FF.W.0224.210819T0039Z-210819T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
539 PM MST Wed Aug 18 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  The Telegraph burn scar in...
  Gila County in east central Arizona...

* Until 945 PM MST.

* At 539 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Telegraph Burn Scar. Between 1 and 2 inches of 
  rain have fallen. Flash flooding is ongoing or expected to begin 
  shortly.

Excessive rainfall over the burn scar will result in a flash flood 
moving through the El Capitan area.

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

  SOURCE...Radar.

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

* Some locations that will experience flash flooding include...
  mainly rural areas of Gila County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3329 11076 3329 11074 3330 11072 3331 11069
      3333 11068 3336 11063 3337 11060 3341 11055
      3337 11046 3335 11047 3334 11049 3334 11053
      3331 11062 3324 11065 3319 11069 3312 11075
      3315 11081 3319 11079 3324 11078

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

$$

MS

1 follow-up statement

777 
WGUS75 KPSR 190441
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
941 PM MST Wed Aug 18 2021

AZC007-190451-
/O.EXP.KPSR.FF.W.0224.000000T0000Z-210819T0445Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-
941 PM MST Wed Aug 18 2021

...FLASH FLOOD WARNING FOR THE TELEGRAPH BURN SCAR WILL EXPIRE AT 
945 PM MST THIS EVENING FOR GILA COUNTY...

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.

LAT...LON 3329 11076 3329 11074 3330 11072 3331 11069
      3333 11068 3336 11063 3337 11060 3341 11055
      3337 11046 3335 11047 3334 11049 3334 11053
      3331 11062 3324 11065 3319 11069 3312 11075
      3315 11081 3319 11079 3324 11078

$$

CK

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 18, 5:13 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 18, 5:20 PM MST	Special Weather Statement	PSR	Gila	40 min
Aug 18, 5:25 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	50 min
Aug 18, 5:34 PM MST	Special Weather Statement	PSR		41 min
Aug 18, 5:40 PM MST	Special Weather Statement	PSR	Maricopa	50 min
Aug 18, 5:43 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	32 min
Aug 18, 5:52 PM MST	Special Weather Statement	PSR		38 min
Aug 18, 6:09 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	3 hr
Aug 18, 6:14 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	3 hr
Aug 18, 6:20 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 18, 6:36 PM MST	Special Weather Statement	PSR		39 min
Aug 18, 7:20 PM MST	Areal Flood Warning	PSR	Maricopa	6 hr
Aug 18, 7:33 PM MST	Areal Flood Warning	PSR	Maricopa	6 hr
Aug 18, 7:33 PM MST	Areal Flood Warning	PSR	Maricopa	6 hr
Aug 18, 8:57 PM MST	Areal Flood Warning	PSR	Maricopa	14 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.