Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 220, NWS Phoenix, AZ

August 18, 2021Gila County, Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 18, 2021, 3:11 PM MST for Gila County, Maricopa County, Arizona. It was in force for 5 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
Aug 18, 2021, 3:11 PM MST (22:11 UTC)
Expired
Aug 18, 2021, 8:15 PM MST
In force
5 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

Counties Gila County, AZ, Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 53 km from the middle of the area, began a volume at 22:12 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

TimeReportWhereRemark
Aug 18, 3:25 PM MSTFLASH FLOOD8 Se Punkin Center, AZADOT REPORTED MUDSLIDE ONTO SR-188, CLOSING THE HIGHWAY BETWEEN MILE MARKERS 246 TO 255.

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 12:00Z, 10.2 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-pSkew-T log-p diagram, Phoenix, AZ at 12:00Z on 2021-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1239 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 12:00Z on 2021-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1239 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
1144 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

855 
WGUS55 KPSR 182211
FFWPSR
AZC007-013-190215-
/O.NEW.KPSR.FF.W.0220.210818T2211Z-210819T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Phoenix has issued a

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

* Until 715 PM MST.

* At 311 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Bush Burn Scar. 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 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...
  Four Peaks and Tonto Basin.

This includes the following streams and drainages...
  Ash Creek, Picadilla Creek, Verde River, Barranca Creek, Boulder 
  Creek, Mesquite Wash, Camp Creek, Salt River, Alder Creek, 
  Sycamore Creek, Buckhorn Creek, Bronco Creek, Cottonwood Creek and 
  Ironwood Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3385 11144 3383 11134 3384 11127 3377 11120
      3372 11125 3363 11127 3357 11127 3357 11136
      3358 11145 3361 11167 3370 11157 3367 11151
      3370 11148 3380 11144

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

$$

MS
2 follow-up statements
042 
WGUS55 KPSR 190120 RRA
FFWPSR
AZC007-013-190315-
/O.EXT.KPSR.FF.W.0220.000000T0000Z-210819T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Phoenix has extended the

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

* Until 815 PM MST.

* At 620 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Bush Burn Scar. 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 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...
  Four Peaks and Tonto Basin.

This includes the following streams and drainages...
  Ash Creek, Picadilla Creek, Verde River, Barranca Creek, Boulder 
  Creek, Mesquite Wash, Camp Creek, Salt River, Alder Creek, 
  Sycamore Creek, Buckhorn Creek, Bronco Creek, Cottonwood Creek and 
  Ironwood Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3385 11144 3383 11134 3384 11127 3377 11120
      3372 11125 3363 11127 3357 11127 3357 11136
      3358 11145 3361 11167 3370 11157 3367 11151
      3370 11148 3380 11144

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

$$

AD
208 
WGUS75 KPSR 190313
FFSPSR

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

AZC007-013-190323-
/O.EXP.KPSR.FF.W.0220.000000T0000Z-210819T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Gila AZ-Maricopa AZ-
813 PM MST Wed Aug 18 2021

...FLASH FLOOD WARNING FOR THE BUSH BURN SCAR WILL EXPIRE AT 815 PM 
MST THIS EVENING FOR GILA AND MARICOPA COUNTIES...

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

LAT...LON 3385 11144 3383 11134 3384 11127 3377 11120
      3372 11125 3363 11127 3357 11127 3357 11136
      3358 11145 3361 11167 3370 11157 3367 11151
      3370 11148 3380 11144

$$

CK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 17, 5:16 PM MSTFlash Flood Warning Considerable damage threatPSRGila6 hr
Aug 17, 6:05 PM MSTFlash Flood Warning Considerable damage threatPSRGila6 hr
Aug 17, 9:08 PM MSTFlash Flood WatchPSRGila, Maricopa, Pinal23 hr
Aug 18, 7:55 AM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 18, 8:48 AM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa, Pinal6 hr
Aug 18, 9:26 AM MSTFlash Flood Warning Considerable damage threatPSRGila, Pinal5 hr
Aug 18, 9:39 AM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 18, 10:16 AM MSTFlash Flood Warning Considerable damage threatPSRGila4 hr
Aug 18, 11:16 AM MSTFlash Flood Warning EmergencyCatastrophic damage threatPSRGila3 hr
Aug 18, 11:37 AM MSTFlash Flood Warning Considerable damage threatPSRGila5 hr
Aug 18, 11:46 AM MSTSevere Thunderstorm WarningPSRMaricopa29 min
Aug 18, 11:59 AM MSTFlash Flood Warning Considerable damage threatPSRMaricopa5 hr
Aug 18, 12:16 PM MSTSevere Thunderstorm WarningPSRMaricopa29 min
Aug 18, 12:26 PM MSTSpecial Weather StatementPSRMaricopa49 min
Aug 18, 12:28 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa5 hr
Aug 18, 12:28 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Aug 18, 12:29 PM MSTSpecial Weather StatementPSR46 min
Aug 18, 12:38 PM MSTSpecial Weather StatementPSR52 min
Aug 18, 12:45 PM MSTSpecial Weather StatementPSR45 min
Aug 18, 12:52 PM MSTSevere Thunderstorm WarningPSRMaricopa53 min
Aug 18, 1:00 PM MSTSevere Thunderstorm WarningPSRMaricopa45 min
Aug 18, 1:06 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa5 hr
Aug 18, 1:11 PM MSTSevere Thunderstorm WarningPSRMaricopa35 min
Aug 18, 1:19 PM MSTSpecial Weather StatementPSRGila41 min
Aug 18, 1:23 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Aug 18, 1:39 PM MSTSpecial Weather StatementPSRMaricopa51 min
Aug 18, 1:40 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Aug 18, 1:46 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa4 hr
Aug 18, 1:47 PM MSTSpecial Weather StatementPSR43 min
Aug 18, 2:09 PM MSTSpecial Weather StatementPSR51 min
Aug 18, 2:13 PM MSTSpecial Weather StatementPSRMaricopa47 min
Aug 18, 2:15 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa6 hr
Aug 18, 2:29 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa46 min
Aug 18, 2:32 PM MSTSpecial Weather StatementPSR43 min
Aug 18, 2:34 PM MSTSpecial Weather StatementPSRGila41 min
Aug 18, 2:45 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa6 hr
Aug 18, 3:02 PM MSTSpecial Weather StatementPSR43 min
Aug 18, 3:03 PM MSTSpecial Weather StatementPSRPinal42 min
Aug 18, 3:19 PM MSTSpecial Weather StatementPSR41 min
Aug 18, 3:33 PM MSTFlash Flood Warning Considerable damage threatPSRGila, Maricopa4 hr
Aug 18, 3:41 PM MSTSpecial Weather StatementPSRGila64 min
Aug 18, 3:46 PM MSTFlash Flood Warning Considerable damage threatPSRGila5 hr
Aug 18, 4:13 PM MSTSpecial Weather StatementPSRMaricopa47 min
Aug 18, 4:39 PM MSTSpecial Weather StatementPSRMaricopa51 min
Aug 18, 4:58 PM MSTSevere Thunderstorm WarningPSRMaricopa32 min

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.