Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 169, NWS Phoenix, AZ

August 13, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 13, 2021, 10:19 PM MST for Maricopa County, Arizona. It was in force for 5 hr. 10 reports 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, 10:19 PM MST (05:19 UTC)
Expired: Aug 14, 2021, 3:30 AM MST
In force: 5 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 51 km from the middle of the area, began a volume at 05:20 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, 10:23 PM MST	FLASH FLOOD	3 S Deer Valley, AZ	FLOODING ON INTERSTATE 17 AT GREENWAY.
Aug 13, 10:27 PM MST	HEAVY RAIN 1.1	5 E Deer Valley, AZ
Aug 13, 10:30 PM MST	HEAVY RAIN 1.04	1 Se Deer Valley, AZ	1.04 IN 20 MINUTES, 0.67 IN 10 MINUTES, AND 0.46 IN 5 MINUTES. MINOR STREET FLOODING NOTED. 2 TREES BLOWN DOWN.
Aug 13, 10:50 PM MST	HEAVY RAIN 2.5	4 Se Deer Valley, AZ	*DELAYED REPORT* HEAVY RAIN LED TO A PARTIAL ROOF COLLAPSE AT MOON VALLEY BIBLE CHURCH. NO INJURIES WERE REPORTED. TIME ESTIMATED FROM HEAVIEST RAINFALL AND RAINFALL ESTIMATED FROM RADAR AND NEARBY MESONET OBSERVATIONS.
Aug 13, 10:55 PM MST	FLASH FLOOD	4 Nw Phoenix, AZ	MULTIPLE CARS STALLED ON I-17 DUE TO STANDING WATER ON I-17 SOUTHBOUND BETWEEN INDIAN SCHOOL AND CAMELBACK.
Aug 13, 11:08 PM MST	FLASH FLOOD	4 Nw Phoenix, AZ	ADOT REPORTS INTERSTATE 17 CLOSED AT INDIAN SCHOOL ROAD IN BOTH DIRECTIONS DUE TO FLOODING.
Aug 13, 11:09 PM MST	FLASH FLOOD	6 Nw Paradise Valley, AZ	*DELAYED REPORT* USGS GAUGE IN INDIAN BEND WASH EXCEEDED ACTION STAGE WITH A ~4 FOOT RISE IN 30 MINUTES, CRESTING AT 3.95FT.
Aug 13, 11:10 PM MST	FLASH FLOOD	2 Sw Phoenix, AZ	ADOT REPORTS INTERSTATE 17 CLOSED IN BOTH DIRECTIONS AT THE DURANGO CURVE DUE TO FLOODING.
Aug 13, 11:10 PM MST	FLASH FLOOD	2 Wsw Phoenix, AZ	I-17 IMPASSABLE AT DURANGO CURVE DUE TO STANDING WATER.
Aug 13, 11:28 PM MST	FLASH FLOOD	4 S Deer Valley, AZ	CAR STRANDED DUE TO 2-3 FEET OF STANDING WATER AT I-17 AND THUNDERBIRD UNDERPASS.

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, 5.3 hours before the alert went out and 22 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.

318 
WGUS55 KPSR 140519
FFWPSR
AZC013-140930-
/O.NEW.KPSR.FF.W.0169.210814T0519Z-210814T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
1019 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...

* Until 230 AM MST.

* At 1019 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to 1 inch of rain has 
  fallen. Additional rainfall amounts up to 1.5 inches 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, Glendale, Scottsdale, Paradise Valley, Laveen, New River, 
  Cave Creek, Carefree, North Mountain Park, Metro Center Mall, Deer 
  Valley Airport, Piestewa Peak Park, Downtown Glendale, Desert 
  Ridge Marketplace, Arizona State Fairgrounds, Downtown Phoenix, 
  Sky Harbor Airport, South Phoenix and South Mountain Park.

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 3381 11189 3364 11194 3358 11199 3332 11204
      3332 11215 3344 11219 3380 11225 3382 11212

FLASH FLOOD...RADAR INDICATED

$$

Rogers

3 follow-up statements

477 
WGUS75 KPSR 140543
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1043 PM MST Fri Aug 13 2021

AZC013-140930-
/O.CON.KPSR.FF.W.0169.000000T0000Z-210814T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1043 PM MST Fri Aug 13 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM MST SATURDAY 
FOR MARICOPA COUNTY...

At 1043 PM MST, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Up to 2 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...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...
  Phoenix, Glendale, Scottsdale, Paradise Valley, Laveen, New River, 
  Cave Creek, Carefree, North Mountain Park, Metro Center Mall, Deer 
  Valley Airport, Piestewa Peak Park, Downtown Glendale, Desert 
  Ridge Marketplace, Arizona State Fairgrounds, Downtown Phoenix, 
  Sky Harbor Airport, South Phoenix and South Mountain Park.

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 3381 11189 3364 11194 3358 11199 3332 11204
      3332 11215 3344 11219 3380 11225 3382 11212

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

$$

Rogers

292 
WGUS75 KPSR 140620
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1120 PM MST Fri Aug 13 2021

AZC013-140930-
/O.CON.KPSR.FF.W.0169.000000T0000Z-210814T0930Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1120 PM MST Fri Aug 13 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 AM MST SATURDAY 
FOR MARICOPA COUNTY...

At 1120 PM MST, Doppler radar indicated thunderstorms producing 
heavy rain across the warned area. Up to 2 inches of rain have 
fallen. The expected rainfall rate is 3 inches in 1 hour. Additional 
rainfall amounts of 0.5 to 1 inch are possible in the warned area. 
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...
  Phoenix, Glendale, Scottsdale, Paradise Valley, Laveen, New River, 
  Cave Creek, Carefree, North Mountain Park, Metro Center Mall, Deer 
  Valley Airport, Piestewa Peak Park, Downtown Glendale, Desert 
  Ridge Marketplace, Arizona State Fairgrounds, Downtown Phoenix, 
  Sky Harbor Airport, South Phoenix and South Mountain Park.

Flash flooding has resulted in the closure of I-17 at the Durango 
Curve.

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 3381 11189 3364 11194 3358 11199 3332 11204
      3332 11215 3344 11219 3380 11225 3382 11212

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

$$

CK

529 
WGUS55 KPSR 140838
FFWPSR
AZC013-141030-
/O.EXT.KPSR.FF.W.0169.000000T0000Z-210814T1030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
138 AM MST Sat Aug 14 2021

The National Weather Service in Phoenix has extended the

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

* Until 330 AM MST.

* At 138 AM MST, Doppler radar and automated rain gauges indicated 
  between 1 and 3 inches of rain have fallen. Flash flooding is 
  already occurring.

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

  SOURCE...Law enforcement reported.

  IMPACT...Life threatening flash flooding of creeks and streams,
           urban areas, highways, streets and underpasses.

* Some locations that will experience flash flooding include...
  Phoenix, Glendale, Scottsdale, Paradise Valley, Laveen, New River, 
  Cave Creek, Carefree, North Mountain Park, and South Phoenix.

Washes will continue to flow and numerous road closures have been 
reported by officials across the warned area.

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.

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

&&

LAT...LON 3381 11189 3364 11194 3358 11199 3332 11204
      3332 11215 3344 11219 3380 11225 3382 11212

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

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, 10:24 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, 11:14 PM MST	Flash Flood Warning	PSR	Maricopa, Pinal	5 hr
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.