Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 7, NWS Phoenix, AZ

July 18, 2017Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 18, 2017, 5:43 PM MST for Maricopa County, Arizona. It was in force for 6 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: Jul 18, 2017, 5:43 PM MST (00:43 UTC)
Expired: Jul 18, 2017, 11:45 PM MST
In force: 6 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 79 km from the middle of the area, began a volume at 00:45 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
Jul 18, 11:26 PM MST	FLASH FLOOD	8 Wsw Mobile, AZ	STATE ROUTE 238 CLOSED DUE TO FLOODING. WEST-BOUND FROM MILE POST 24.0 TO GILA BEND. DURATION: TUE, 18 JUL 2017 11:26 PM TO WED, 19 JUL 2017 12:26 AM.

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, 0.7 hours before the alert went out and 66 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: 1393 J/kg
Mixed-layer CIN: -61 J/kg
Mixed-layer LCL: 1792 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: -22 m²/s²
0-3 km storm-relative helicity: -19 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

193 
WGUS55 KPSR 190043
FFWPSR
AZC013-190345-
/O.NEW.KPSR.FF.W.0007.170719T0043Z-170719T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
543 PM MST TUE JUL 18 2017

The National Weather Service in Phoenix has issued a

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

* Until 845 PM MST

* At 541 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the South Maricopa Mountains. Flash flooding is 
  expected to begin shortly and impact one or more road crossings 
  along Highway 238.

* Some locations that will experience flooding include...
  Gila Bend, Estrella, Bosque and Sonoran National Monument. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3308 11231 3298 11234 3284 11232 3293 11266
      3298 11267

$$

MS

3 follow-up statements

039 
WGUS75 KPSR 190145
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
645 PM MST TUE JUL 18 2017

AZC013-190345-
/O.CON.KPSR.FF.W.0007.000000T0000Z-170719T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
645 PM MST TUE JUL 18 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MST FOR
MARICOPA COUNTY...

At 641 PM MST, over the past hour upwards of an inch of rain has 
fallen upstream of Highway 238.  Several washes that cross the 
highway should be flowing swiftly.

Some locations that will experience flooding include...
Highway 238, Estrella, Bosque and Sonoran National Monument. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3308 11231 3298 11234 3284 11232 3293 11266
      3298 11267

$$

MS

065 
WGUS55 KPSR 190336
FFWPSR
AZC013-190645-
/O.EXT.KPSR.FF.W.0007.000000T0000Z-170719T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
836 PM MST TUE JUL 18 2017

The National Weather Service in Phoenix has extended the

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

* Until 1145 PM MST

* At 831 PM MST, Doppler radar indicated thunderstorms continued to 
  cause heavy rainfall just upstream of Highway 238 east of Gila 
  Bend and west of Mobile.

* Some locations that will experience flooding include...
  Highway 238, Estrella, Bosque and Sonoran National Monument. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3308 11231 3298 11234 3284 11232 3293 11266
      3298 11267

$$

MS

518 
WGUS75 KPSR 190646
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
1146 PM MST TUE JUL 18 2017

AZC013-190655-
/O.EXP.KPSR.FF.W.0007.000000T0000Z-170719T0645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-
1146 PM MST TUE JUL 18 2017

...THE FLASH FLOOD WARNING FOR MARICOPA COUNTY HAS EXPIRED...

The heavy rain has ended. Flood waters have receded. Flooding is no
longer expected to pose a threat. Please continue to heed any
remaining road closures.

LAT...LON 3308 11231 3298 11234 3284 11232 3293 11266
      3298 11267

$$

THW

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 6:01 PM MST	Special Weather Statement	PSR	Maricopa	44 min
Jul 18, 6:06 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	24 min
Jul 18, 6:11 PM MST	Special Weather Statement	PSR		49 min
Jul 18, 6:15 PM MST	Special Weather Statement	PSR		45 min
Jul 18, 6:26 PM MST	Blowing Dust Advisory	PSR	Pinal	3 hr
Jul 18, 6:40 PM MST	Flash Flood Warning	PSR	Maricopa	3 hr
Jul 18, 7:26 PM MST	Special Weather Statement	PSR		49 min
Jul 18, 8:02 PM MST	Flash Flood Warning	PSR	La Paz, Maricopa	3 hr
Jul 18, 10:22 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Jul 19, 12:42 PM MST	Areal Flood Advisory	PSR	Gila, Pinal	2 hr
Jul 19, 1:10 PM MST	Special Weather Statement	PSR	Maricopa	50 min
Jul 19, 2:32 PM MST	Special Weather Statement	PSR	Gila	28 min
Jul 19, 2:34 PM MST	Special Weather Statement	PSR	Maricopa	26 min
Jul 19, 4:10 PM MST	Special Weather Statement	PSR		35 min
Jul 19, 4:57 PM MST	Special Weather Statement	PSR	Pinal	48 min

Nearby

Flash Flood Warnings in Arizona, 2017 Every flash flood warning in 2017

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.