Alert archive / Arizona / Flash Flood Warnings in 2017

Flash Flood Warning 39, NWS Phoenix, AZ

August 3, 2017Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 3, 2017, 6:58 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 3 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 3, 2017, 6:58 PM MST (01:58 UTC)
Expired: Aug 3, 2017, 10:00 PM MST
In force: 3 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), 61 km from the middle of the area, began a volume at 01:58 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 3, 7:00 PM MST	FLASH FLOOD	6 E Casa Grande, AZ	OVERFIELD ROAD BETWEEN FLORENCE HIGHWAY 287 AND SELMA HIGHWAY CLOSED DUE TO WATER OVER ROAD. REPORT FROM CITY OF CASA GRANDE PUBLIC WORKS DEPARTMENT. DELAYED REPORT.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Tuscon, AZ (KDMA), launched 00:00Z, 2.0 hours before the alert went out and 119 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: 236 J/kg
Mixed-layer CIN: -157 J/kg
Mixed-layer LCL: 2037 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -33 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.

651 
WGUS55 KPSR 040158
FFWPSR
AZC013-021-040500-
/O.NEW.KPSR.FF.W.0039.170804T0158Z-170804T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Phoenix AZ
658 PM MST THU AUG 3 2017

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 1000 PM MST

* At 658 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Up to one and a half inches of 
  rain has already fallen. Flash flooding is expected to begin 
  shortly.

* Some locations that will experience flooding include...
  Casa Grande, Coolidge, Arizona City, La Palma, Toltec, Arizola,
  Randolph and Stanfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3288 11222 3302 11153 3286 11150 3274 11165
      3273 11174 3280 11178 3279 11187 3277 11189
      3276 11205 3272 11207 3272 11214 3268 11215
      3266 11223

$$

Hernandez

2 follow-up statements

793 
WGUS75 KPSR 040335
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
835 PM MST THU AUG 3 2017

AZC013-021-040500-
/O.CON.KPSR.FF.W.0039.000000T0000Z-170804T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
835 PM MST THU AUG 3 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1000 PM MST FOR
MARICOPA AND PINAL COUNTIES...

At 834 PM MST, although heavy rain has ended, drainage from Santa 
Rosa and Vekol wash continue to cause flooding impacts. Please 
continue to heed any remaining road closures.

Some locations that will experience flooding include...
Casa Grande, Coolidge, Arizona City, La Palma, Toltec, Arizola,
Randolph and Stanfield.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3288 11222 3302 11153 3286 11150 3274 11165
      3273 11174 3280 11178 3279 11187 3277 11189
      3276 11205 3272 11207 3272 11214 3268 11215
      3266 11223

$$

Hernandez

301 
WGUS75 KPSR 040423
FFSPSR

Flash Flood Statement
National Weather Service Phoenix AZ
923 PM MST THU AUG 3 2017

AZC013-021-040431-
/O.CAN.KPSR.FF.W.0039.000000T0000Z-170804T0500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Maricopa AZ-Pinal AZ-
923 PM MST THU AUG 3 2017

...THE FLASH FLOOD WARNING FOR MARICOPA AND PINAL COUNTIES IS
CANCELLED...

The heavy rain has ended but additional runoff impacts will continue 
into the evening and will be covered with an Areal Flood Warning. 
Please continue to heed any remaining road closures.

LAT...LON 3288 11222 3302 11153 3286 11150 3274 11165
      3273 11174 3280 11178 3279 11187 3277 11189
      3276 11205 3272 11207 3272 11214 3268 11215
      3266 11223

$$

Hernandez

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 3, 5:02 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	28 min
Aug 3, 5:06 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	24 min
Aug 3, 5:16 PM MST	Special Weather Statement	PSR	Pinal	44 min
Aug 3, 5:17 PM MST	Blowing Dust Advisory	PSR	Maricopa, Pinal	103 min
Aug 3, 5:19 PM MST	Flash Flood Warning	PSR	Maricopa, Pinal	3 hr
Aug 3, 5:27 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	48 min
Aug 3, 5:28 PM MST	Flash Flood Warning	PSR	Maricopa	3 hr
Aug 3, 5:36 PM MST	Special Weather Statement	PSR		39 min
Aug 3, 5:39 PM MST	Special Weather Statement	PSR	Pinal	51 min
Aug 3, 6:01 PM MST	Special Weather Statement	PSR		44 min
Aug 3, 6:03 PM MST	Flash Flood Warning	PSR	Maricopa, Pinal	3 hr
Aug 3, 6:09 PM MST	Special Weather Statement	PSR	Pinal	51 min
Aug 3, 6:36 PM MST	Special Weather Statement	PSR	Pinal	39 min
Aug 3, 6:50 PM MST	Special Weather Statement	PSR	Pinal	40 min
Aug 3, 8:00 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 3, 8:03 PM MST	Areal Flood Warning	PSR	Maricopa, Pinal	3 hr
Aug 3, 8:21 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 3, 8:28 PM MST	Areal Flood Warning	PSR	Maricopa	3 hr
Aug 3, 8:31 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	3 hr
Aug 3, 9:21 PM MST	Areal Flood Warning	PSR	Maricopa, Pinal	3 hr
Aug 4, 4:59 PM MST	Areal Flood Advisory	PSR	La Paz	3 hr

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.