Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 101, NWS Phoenix, AZ

July 26, 2021La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 26, 2021, 6:57 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: Jul 26, 2021, 6:57 PM MST (01:57 UTC)
Expired: Jul 26, 2021, 11:00 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), 153 km from the middle of the area, began a volume at 02:00 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, 2.0 hours before the alert went out and 178 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: 5 J/kg
Mixed-layer CIN: -96 J/kg
Mixed-layer LCL: 2470 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: -17 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

882 
WGUS55 KPSR 270157
FFWPSR
AZC012-270600-
/O.NEW.KPSR.FF.W.0101.210727T0157Z-210727T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
657 PM MST Mon Jul 26 2021

The National Weather Service in Phoenix has issued a

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

* Until 1100 PM MST.

* At 657 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 1 and 1.5 inches of 
  rain have fallen. Additional rainfall amounts up to 0.5 inches 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...
  Brenda.

This includes the following highways...
	AZ Interstate 10 between mile markers 36 and 45.
	AZ Route 72 between mile markers 33 and 42.
	US Highway 60 between mile markers 36 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3362 11388 3362 11394 3373 11395 3388 11393
      3383 11377 3361 11370

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

$$

INS

2 follow-up statements

635 
WGUS75 KPSR 270408
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
908 PM MST Mon Jul 26 2021

AZC012-270600-
/O.CON.KPSR.FF.W.0101.000000T0000Z-210727T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
908 PM MST Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM MST THIS 
EVENING FOR CENTRAL LA PAZ COUNTY...

At 908 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1 and 1.5 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...
  Brenda.

This includes the following highways...
	AZ Interstate 10 between mile markers 36 and 45.
	AZ Route 72 between mile markers 34 and 43.
	US Highway 60 between mile markers 36 and 45.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3362 11388 3362 11394 3373 11395 3388 11393
      3383 11377 3361 11370

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

$$

INS

873 
WGUS75 KPSR 270555
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1055 PM MST Mon Jul 26 2021

AZC012-270605-
/O.EXP.KPSR.FF.W.0101.000000T0000Z-210727T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
1055 PM MST Mon Jul 26 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 11 PM MST THIS EVENING FOR 
CENTRAL LA PAZ 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 3362 11388 3362 11394 3373 11395 3388 11393
      3383 11377 3361 11370

$$

18

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 26, 5:26 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr
Jul 26, 5:32 PM MST	Special Weather Statement	PSR	La Paz	28 min
Jul 26, 6:21 PM MST	Special Weather Statement	PSR	La Paz	24 min
Jul 26, 8:47 PM MST	Special Weather Statement	PSR		28 min
Jul 26, 9:24 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 27, 1:44 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	2 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.