Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 229, NWS Phoenix, AZ

August 30, 2021La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 30, 2021, 2:55 PM MST for La Paz 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 30, 2021, 2:55 PM MST (21:55 UTC)
Expired
Aug 30, 2021, 7:00 PM MST
In force
4 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 155 km from the middle of the area, began a volume at 21:56 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 12:00Z, 9.9 hours before the alert went out and 200 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 2021-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 126 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 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 2021-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -25 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
126 J/kg
Mixed-layer CIN
-355 J/kg
Mixed-layer LCL
2569 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-25 m²/s²
0-3 km storm-relative helicity
59 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

259 
WGUS55 KPSR 302155
FFWPSR
AZC012-310200-
/O.NEW.KPSR.FF.W.0229.210830T2155Z-210831T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
255 PM MST Mon Aug 30 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Central La Paz County in west central Arizona...

* Until 700 PM MST.

* At 255 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 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...
  Quartzsite and Bouse.

This includes the following highways...
	AZ Route 72 between mile markers 26 and 35.
	AZ Route 95 between mile markers 111 and 120.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3368 11424 3386 11424 3396 11399 3386 11388
      3377 11392

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

$$

INS
2 follow-up statements
755 
WGUS75 KPSR 302301
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
401 PM MST Mon Aug 30 2021

AZC012-310200-
/O.CON.KPSR.FF.W.0229.000000T0000Z-210831T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
401 PM MST Mon Aug 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING 
FOR CENTRAL LA PAZ COUNTY...

At 401 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Up to 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...
  Quartzsite and Bouse.

This includes the following highways...
	AZ Route 72 between mile markers 26 and 35.
	AZ Route 95 between mile markers 111 and 120.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3368 11424 3386 11424 3396 11399 3386 11388
      3377 11392

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

$$

INS
486 
WGUS75 KPSR 310152
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
652 PM MST Mon Aug 30 2021

AZC012-310202-
/O.EXP.KPSR.FF.W.0229.000000T0000Z-210831T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
652 PM MST Mon Aug 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 7 PM MST THIS EVENING FOR 
CENTRAL LA PAZ 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 11424 3386 11424 3396 11399 3386 11388
      3377 11392

$$

INS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 5:05 PM MSTSpecial Weather StatementPSR25 min
Aug 29, 5:23 PM MSTAreal Flood AdvisoryPSRLa Paz, Maricopa2 hr
Aug 29, 6:07 PM MSTSpecial Weather StatementPSRPinal23 min
Aug 30, 12:42 AM MSTAreal Flood AdvisoryPSRMaricopa, Pinal4 hr
Aug 30, 1:43 AM MSTFlash Flood WatchPSRGila, La Paz, Maricopa, Pinal, Yuma3 days
Aug 30, 1:41 PM MSTSpecial Weather StatementPSRLa Paz34 min
Aug 30, 1:55 PM MSTSevere Thunderstorm WarningPSRLa Paz50 min
Aug 30, 2:24 PM MSTAreal Flood AdvisoryPSRLa Paz, Yuma3 hr
Aug 30, 3:04 PM MSTSpecial Weather StatementPSRLa Paz26 min
Aug 30, 3:21 PM MSTSpecial Weather StatementPSR24 min
Aug 30, 3:32 PM MSTSpecial Weather StatementPSRLa Paz28 min
Aug 30, 3:47 PM MSTDust Storm AdvisoryPSRLa Paz58 min
Aug 30, 4:48 PM MSTSpecial Weather StatementPSR42 min
Aug 30, 4:51 PM MSTSpecial Weather StatementPSRGila39 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.