Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 173, NWS Phoenix, AZ

August 13, 2021Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 13, 2021, 11:14 PM MST for Maricopa County, Pinal 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 13, 2021, 11:14 PM MST (06:14 UTC)
Expired: Aug 14, 2021, 4:15 AM MST
In force: 5 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 16 km from the middle of the area, began a volume at 06:13 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

Time	Report	Where	Remark
Aug 13, 11:19 PM MST	FLASH FLOOD	5 Ene Phoenix Mesa Gate, AZ	*DELAYED REPORT* STREET FLOODING. ROADS CLOSED. REPORT FROM MPING.

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 00:00Z, 6.2 hours before the alert went out and 23 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: 1603 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 2033 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 78 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

592 
WGUS55 KPSR 140614
FFWPSR
AZC013-021-141115-
/O.NEW.KPSR.FF.W.0173.210814T0614Z-210814T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1114 PM MST Fri Aug 13 2021

The National Weather Service in Phoenix has issued a

* Flash Flood Warning for...
  Maricopa County in south central Arizona...
  Pinal County in southeastern Arizona...

* Until 415 AM MST.

* At 1114 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 1.5 inches of 
  rain have fallen. The expected rainfall rate is 3 inches in 1 
  hour. Additional rainfall amounts up to 1 inch are possible in the 
  warned area. Flash flooding is ongoing or expected to begin 
  shortly.

  HAZARD...Flash flooding caused by thunderstorms.

  SOURCE...Radar.

  IMPACT...Flash flooding of small creeks and streams, urban
           areas, highways, streets and underpasses as well as
           other poor drainage and low-lying areas.

* Some locations that will experience flash flooding include...
  Phoenix, Mesa, Chandler, Scottsdale, Gilbert, Tempe, Apache 
  Junction, Paradise Valley, East Mesa, Gold Canyon, Queen Creek, 
  Superstition Springs Mall, Falcon Field Airport, Freestone Park, 
  Granite Reef Dam, Usery Mountain Park, Downtown Mesa, Fiesta Mall, 
  Mesa Riverview Mall and Salt River Indian Community.

This includes the following streams and drainages...
 Indian Bend Wash.

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.

&&

LAT...LON 3345 11201 3358 11199 3364 11194 3356 11191
      3354 11174 3361 11157 3352 11151 3346 11143
      3336 11133 3329 11136 3318 11147 3327 11158
      3338 11171 3327 11195 3326 11206

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3 INCHES IN 1 HOUR

$$

Rogers

2 follow-up statements

916 
WGUS75 KPSR 140704
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1204 AM MST Sat Aug 14 2021

AZC013-021-141115-
/O.CON.KPSR.FF.W.0173.000000T0000Z-210814T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
1204 AM MST Sat Aug 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 AM MST EARLY THIS 
MORNING FOR MARICOPA AND PINAL COUNTIES...

At 1204 AM MST, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Between 0.5 and 1.5 inches of 
rain have fallen. The expected rainfall rate is 3 inches in 1 hour. 
Additional rainfall amounts up to 1 inch are possible in the warned 
area. Flash flooding is ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Phoenix, Mesa, Chandler, Scottsdale, Gilbert, Tempe, Apache 
  Junction, Paradise Valley, East Mesa, Gold Canyon, Queen Creek, 
  Superstition Springs Mall, Falcon Field Airport, Freestone Park, 
  Granite Reef Dam, Usery Mountain Park, Downtown Mesa, Fiesta Mall, 
  Mesa Riverview Mall and Salt River Indian Community.

This includes the following streams and drainages...
  Verde River, Bulldog Wash, Salt River, Queen Creek, Indian Bend 
  Wash and First Water Creek.

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.

&&

LAT...LON 3345 11201 3358 11199 3364 11194 3356 11191
      3354 11174 3361 11157 3352 11151 3346 11143
      3336 11133 3329 11136 3318 11147 3327 11158
      3338 11171 3327 11195 3326 11206

FLASH FLOOD...RADAR INDICATED
EXPECTED RAINFALL...3 INCHES IN 1 HOUR

$$

CK

655 
WGUS75 KPSR 140910
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
210 AM MST Sat Aug 14 2021

AZC013-021-141115-
/O.CON.KPSR.FF.W.0173.000000T0000Z-210814T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
210 AM MST Sat Aug 14 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 AM MST EARLY THIS 
MORNING FOR MARICOPA AND PINAL COUNTIES...

At 210 AM MST, Doppler radar and automated rain gauges indicated 
between 1 and 2 inches of rain have fallen. Flash flooding is 
ongoing or expected to begin shortly.

HAZARD...Flash flooding caused by thunderstorms.

SOURCE...Radar and automated gauges.

IMPACT...Flash flooding of small creeks and streams, urban areas,
         highways, streets and underpasses as well as other poor
         drainage and low-lying areas.

Some locations that will experience flash flooding include...
  Phoenix, Mesa, Chandler, Scottsdale, Gilbert, Tempe, Apache 
  Junction, Paradise Valley, East Mesa, Gold Canyon, and Queen Creek.

This includes the following streams and drainages...
 Indian Bend Wash.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

&&

LAT...LON 3345 11201 3358 11199 3364 11194 3356 11191
      3354 11174 3361 11157 3352 11151 3346 11143
      3336 11133 3329 11136 3318 11147 3327 11158
      3338 11171 3327 11195 3326 11206

FLASH FLOOD...RADAR AND GAUGE INDICATED

$$

Iniguez

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 13, 5:14 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa, Pinal	46 min
Aug 13, 5:57 PM MST	Special Weather Statement	PSR	Pinal	48 min
Aug 13, 8:34 PM MST	Special Weather Statement	PSR		41 min
Aug 13, 8:58 PM MST	Special Weather Statement	PSR		47 min
Aug 13, 9:03 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	42 min
Aug 13, 9:19 PM MST	Severe Thunderstorm Warning	PSR	Gila, Maricopa	41 min
Aug 13, 9:38 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	52 min
Aug 13, 9:49 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	4 hr
Aug 13, 9:54 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	51 min
Aug 13, 9:56 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Aug 13, 9:58 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Gila, Maricopa, Pinal	47 min
Aug 13, 10:02 PM MST	Dust Storm Warning	PSR	La Paz, Maricopa	58 min
Aug 13, 10:05 PM MST	Special Weather Statement	PSR	Pinal	40 min
Aug 13, 10:11 PM MST	Special Weather Statement	PSR	Maricopa	49 min
Aug 13, 10:16 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	44 min
Aug 13, 10:19 PM MST	Flash Flood Warning	PSR	Maricopa	5 hr
Aug 13, 10:24 PM MST	Severe Thunderstorm Warning	PSR	La Paz, Maricopa	36 min
Aug 13, 10:31 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila, Maricopa	4 hr
Aug 13, 10:39 PM MST	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Aug 13, 10:44 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	Gila, Maricopa, Pinal	46 min
Aug 13, 10:58 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	5 hr
Aug 13, 11:01 PM MST	Severe Thunderstorm Warning Considerable damage threat	PSR	La Paz, Maricopa, Yuma	44 min
Aug 13, 11:05 PM MST	Dust Storm Warning	PSR	La Paz, Maricopa, Yuma	55 min
Aug 13, 11:11 PM MST	Special Weather Statement	PSR	Maricopa	49 min
Aug 13, 11:25 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	65 min
Aug 13, 11:31 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	5 hr
Aug 13, 11:31 PM MST	Severe Thunderstorm Warning	PSR	Gila	44 min
Aug 13, 11:32 PM MST	Special Weather Statement	PSR	Maricopa	58 min
Aug 13, 11:43 PM MST	Severe Thunderstorm Warning	PSR	La Paz, Maricopa, Yuma	47 min
Aug 13, 11:49 PM MST	Special Weather Statement	PSR	La Paz	41 min
Aug 13, 11:51 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Aug 14, 12:03 AM MST	Dust Storm Advisory	PSR	La Paz, Maricopa, Yuma	57 min
Aug 14, 12:15 AM MST	Special Weather Statement	PSR	Gila	45 min
Aug 14, 12:32 AM MST	Special Weather Statement	PSR	Yuma	43 min
Aug 14, 12:33 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa, Pinal	4 hr
Aug 14, 12:35 AM MST	Special Weather Statement	PSR	Maricopa	40 min
Aug 14, 12:53 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Aug 14, 1:03 AM MST	Severe Thunderstorm Warning	PSR	Maricopa, Yuma	57 min
Aug 14, 1:04 AM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz, Maricopa, Yuma	4 hr
Aug 14, 1:20 AM MST	Special Weather Statement	PSR	Maricopa	40 min
Aug 14, 1:37 AM MST	Special Weather Statement	PSR	Yuma	38 min
Aug 14, 1:54 AM MST	Dust Storm Warning	PSR	La Paz, Yuma	51 min
Aug 14, 2:26 AM MST	Special Weather Statement	PSR	Yuma	49 min
Aug 14, 3:35 AM MST	Areal Flood Warning	PSR	Maricopa	6 hr
Aug 14, 3:44 AM MST	Areal Flood Warning	PSR	Maricopa	11 hr
Aug 14, 12:17 PM MST	Areal Flood Warning	PSR	Maricopa	6 hr
Aug 14, 1:19 PM MST	Flash Flood Warning Considerable damage threat	PSR	Pinal	4 hr
Aug 14, 2:59 PM MST	Special Weather Statement	PSR	Gila	46 min
Aug 14, 3:26 PM MST	Areal Flood Advisory	PSR	Gila	3 hr
Aug 14, 4:55 PM MST	Special Weather Statement	PSR	Gila	50 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.