Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 46, NWS Phoenix, AZ

July 19, 2021La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 19, 2021, 6:52 PM MST for La Paz County, Arizona. It was in force for 2 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 19, 2021, 6:52 PM MST (01:52 UTC)
Expired
Jul 19, 2021, 9:10 PM MST
In force
2 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County La Paz County, AZ

The radar

The Las Vegas radar (KESX), 181 km from the middle of the area, began a volume at 01:52 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, 1.9 hours before the alert went out and 209 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 00:00Z on 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 431 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 00:00Z on 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -22 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
431 J/kg
Mixed-layer CIN
-80 J/kg
Mixed-layer LCL
2659 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-22 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

446 
WGUS55 KPSR 200152
FFWPSR
AZC012-200600-
/O.NEW.KPSR.FF.W.0046.210720T0152Z-210720T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
652 PM MST Mon Jul 19 2021

The National Weather Service in Phoenix has issued a

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

* Until 1100 PM MST.

* At 652 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 already occurring.

  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 North Central La Paz County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3425 11389 3417 11389 3414 11391 3413 11402
      3414 11409 3419 11412 3423 11411 3430 11411
      3430 11409 3429 11407 3428 11405 3427 11405
      3427 11404 3426 11404 3427 11402 3425 11401
      3426 11396 3426 11394 3425 11393

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

$$

JS
2 follow-up statements
913 
WGUS75 KPSR 200236
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
736 PM MST Mon Jul 19 2021

AZC012-200600-
/O.CON.KPSR.FF.W.0046.000000T0000Z-210720T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
736 PM MST Mon Jul 19 2021

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

At 736 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 1.5 and 2.5 inches of rain have 
fallen. Flash flooding is already occurring.

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 North Central La Paz County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be especially cautious at night when it is harder to recognize the 
dangers of flooding.

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 3425 11389 3417 11389 3414 11391 3413 11402
      3414 11409 3419 11412 3423 11411 3430 11411
      3430 11409 3429 11407 3428 11405 3427 11405
      3427 11404 3426 11404 3427 11402 3425 11401
      3426 11396 3426 11394 3425 11393

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

$$

JS
544 
WGUS75 KPSR 200410
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
910 PM MST Mon Jul 19 2021

AZC012-200420-
/O.CAN.KPSR.FF.W.0046.000000T0000Z-210720T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
La Paz AZ-
910 PM MST Mon Jul 19 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTH 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 3425 11389 3417 11389 3414 11391 3413 11402
      3414 11409 3419 11412 3423 11411 3430 11411
      3430 11409 3429 11407 3428 11405 3427 11405
      3427 11404 3426 11404 3427 11402 3425 11401
      3426 11396 3426 11394 3425 11393

$$

18

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 19, 6:20 PM MSTSpecial Weather StatementPSRLa Paz40 min
Jul 20, 1:33 PM MSTSpecial Weather StatementPSR42 min
Jul 20, 1:41 PM MSTSpecial Weather StatementPSR49 min
Jul 20, 2:02 PM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Jul 20, 2:17 PM MSTSpecial Weather StatementPSR43 min
Jul 20, 2:28 PM MSTSpecial Weather StatementPSR32 min
Jul 20, 2:37 PM MSTSpecial Weather StatementPSR53 min
Jul 20, 2:43 PM MSTSpecial Weather StatementPSR47 min
Jul 20, 2:57 PM MSTSpecial Weather StatementPSR48 min
Jul 20, 3:05 PM MSTSpecial Weather StatementPSR40 min
Jul 20, 3:08 PM MSTSpecial Weather StatementPSR52 min
Jul 20, 3:20 PM MSTSpecial Weather StatementPSRLa Paz40 min
Jul 20, 3:32 PM MSTFlash Flood Warning Considerable damage threatPSRLa Paz, Maricopa3 hr
Jul 20, 3:36 PM MSTSpecial Weather StatementPSR39 min
Jul 20, 3:47 PM MSTSpecial Weather StatementPSR43 min
Jul 20, 3:55 PM MSTFlash Flood Warning Considerable damage threatPSRMaricopa3 hr
Jul 20, 4:21 PM MSTSpecial Weather StatementPSR39 min
Jul 20, 4:23 PM MSTSpecial Weather StatementPSRLa Paz52 min
Jul 20, 4:30 PM MSTSpecial Weather StatementPSR45 min
Jul 20, 4:41 PM MSTFlash Flood Warning Considerable damage threatPSRLa Paz3 hr
Jul 20, 4:47 PM MSTSpecial Weather StatementPSRGila43 min
Jul 20, 4:53 PM MSTAreal Flood AdvisoryPSRLa Paz3 hr
Jul 20, 4:57 PM MSTAreal Flood AdvisoryPSRLa Paz3 hr

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.