Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 128, NWS Phoenix, AZ

August 8, 2021La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 8, 2021, 6:28 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 8, 2021, 6:28 PM MST (01:28 UTC)
Expired: Aug 8, 2021, 10:30 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), 145 km from the middle of the area, began a volume at 01:28 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, 1.5 hours before the alert went out and 175 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: 178 J/kg
Mixed-layer CIN: -68 J/kg
Mixed-layer LCL: 3240 m above ground
0-6 km bulk shear: 2 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

926 
WGUS55 KPSR 090128
FFWPSR
AZC012-090530-
/O.NEW.KPSR.FF.W.0128.210809T0128Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
628 PM MST Sun Aug 8 2021

The National Weather Service in Phoenix has issued a

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

* Until 1030 PM MST.

* At 628 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 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.

  SOURCE...Radar.

  IMPACT...Life threatening flash flooding of normally dry
           washes, rural highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  mainly rural areas of Central La Paz County

This includes the following highways...
	AZ Interstate 10 between mile markers 35 and 44.
	US Highway 60 between mile markers 37 and 43.

This includes the following streams and drainages...
  Bouse Wash, Alamo Wash, and Calcite Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3361 11398 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3355 11375
      3351 11376 3350 11378 3350 11379 3351 11385
      3354 11389 3358 11395

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

$$

AJ

5 follow-up statements

018 
WGUS75 KPSR 090147
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
647 PM MST Sun Aug 8 2021

AZC012-090530-
/O.CON.KPSR.FF.W.0128.000000T0000Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
647 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM MST THIS 
EVENING FOR CENTRAL LA PAZ COUNTY...

At 647 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. 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.

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 Central La Paz County

This includes the following highways...
	AZ Interstate 10 between mile markers 35 and 44.
	US Highway 60 between mile markers 37 and 43.

This includes the following streams and drainages...
  Alamo Wash and Calcite Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3361 11398 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3355 11375
      3351 11376 3350 11378 3350 11379 3351 11385
      3354 11389 3358 11395

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

$$

AJ

203 
WGUS75 KPSR 090214
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
714 PM MST Sun Aug 8 2021

AZC012-090530-
/O.CON.KPSR.FF.W.0128.000000T0000Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
714 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM MST THIS 
EVENING FOR CENTRAL LA PAZ COUNTY...

At 714 PM MST, Doppler radar indicated between 1.5 and 2.5 inches of 
rain have fallen in the past two hours. Flash flooding is likely 
ongoing.

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 Central La Paz County

This includes the following highways...
	AZ Interstate 10 between mile markers 35 and 44.
	US Highway 60 between mile markers 37 and 43.

This includes the following streams and drainages...
  Bouse Wash, Alamo Wash, and Calcite Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3361 11398 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3355 11375
      3351 11376 3350 11378 3350 11379 3351 11385
      3354 11389 3358 11395

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

$$

AJ

833 
WGUS75 KPSR 090256
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
756 PM MST Sun Aug 8 2021

AZC012-090530-
/O.CON.KPSR.FF.W.0128.000000T0000Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
756 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM MST THIS 
EVENING FOR CENTRAL LA PAZ COUNTY...

At 756 PM MST, Doppler radar indicated Between 1.5 and 2.5 inches of 
rain have fallen in the Warning area. Though storms have ended, 
runoff is likely causing flash flooding in normally dry washes.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of normally dry washes,
         streets and underpasses.

Some locations that will experience flash flooding include...
  mainly rural areas of Central La Paz County

This includes the following highways...
	AZ Interstate 10 between mile markers 37 and 45.
	US Highway 60 between mile markers 38 and 43.

This includes the following streams and drainages...
  Alamo Wash and Calcite Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3360 11394 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3356 11376
      3354 11378 3353 11378 3354 11383 3356 11388
      3359 11393

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

$$

AJ

713 
WGUS75 KPSR 090413
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
913 PM MST Sun Aug 8 2021

AZC012-090530-
/O.CON.KPSR.FF.W.0128.000000T0000Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
913 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM MST THIS 
EVENING FOR CENTRAL LA PAZ COUNTY...

At 913 PM MST, Doppler radar indicated between 1.5 and 2.5 inches of 
rain have fallen in the warned area. Though storms have ended, 
runoff is likely causing flash flooding in normally dry washes.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

IMPACT...Life threatening flash flooding of normally dry washes,
         streets and underpasses.

Some locations that will experience flash flooding include...
  mainly rural areas of Central La Paz County

This includes the following highways...
	AZ Interstate 10 between mile markers 37 and 45.
	US Highway 60 between mile markers 38 and 43.
    Vicksburg Road south of Interstate 10.

This includes the following streams and drainages...
  Bouse Wash, Alamo Wash, and Calcite Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3360 11394 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3356 11376
      3354 11378 3353 11378 3354 11383 3356 11388
      3359 11393

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

$$

Iniguez

168 
WGUS75 KPSR 090520
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1020 PM MST Sun Aug 8 2021

AZC012-090530-
/O.EXP.KPSR.FF.W.0128.000000T0000Z-210809T0530Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
1020 PM MST Sun Aug 8 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1030 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 3360 11394 3376 11387 3375 11386 3374 11384
      3372 11382 3365 11376 3361 11376 3356 11376
      3354 11378 3353 11378 3354 11383 3356 11388
      3359 11393

$$

Iniguez

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 5:37 PM MST	Special Weather Statement	PSR	La Paz	38 min
Aug 8, 6:06 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Aug 8, 6:21 PM MST	Dust Storm Advisory	PSR	La Paz, Maricopa	54 min
Aug 8, 6:46 PM MST	Special Weather Statement	PSR	La Paz	44 min
Aug 8, 7:51 PM MST	Areal Flood Advisory	PSR	La Paz	114 min
Aug 9, 6:20 AM MST	Special Weather Statement	PSR	Pinal	55 min
Aug 9, 7:56 AM MST	Areal Flood Advisory	PSR	Pinal	3 hr
Aug 9, 2:57 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Aug 9, 3:32 PM MST	Special Weather Statement	PSR	La Paz	43 min
Aug 9, 4:11 PM MST	Special Weather Statement	PSR		49 min
Aug 9, 4:30 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 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.