Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 35, NWS Phoenix, AZ

August 17, 2012Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 17, 2012, 11:42 AM MST for Maricopa 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: Aug 17, 2012, 11:42 AM MST (18:42 UTC)
Expired: Aug 17, 2012, 1:47 PM MST
In force: 2 hr
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Flood severity: None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 97 km from the middle of the area, began a volume at 18:46 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

Tuscon, AZ (KDMA), launched 12:00Z, 6.7 hours before the alert went out and 147 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: 560 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 1232 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -2 m²/s²
0-3 km storm-relative helicity: 47 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

231 
WGUS55 KPSR 171842
FFWPSR
AZC013-172145-
/O.NEW.KPSR.FF.W.0035.120817T1842Z-120817T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1142 AM MST FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EXTREME SOUTH CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA...

* UNTIL 245 PM MST

* AT 1132 AM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS
  DETECTED   VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING. THIS
  INCLUDES PORTIONS OF THE TOHONO OODHAM RESERVATION...THE GOLDWATER
  AIR FORCE RANGE...AND THE VEKOL VALLEY.

* THE STORM PRODUCING VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING
  WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE INDICATED
  COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF NORMALLY
DRY WASHES AND CREEKS...ROADS...AND LOW LYING SPOTS. UNBRIDGED
CROSSINGS WILL BE ESPECIALLY DANGEROUS.

NEVER ATTEMPT TO CROSS FLOWING WATER OR WATER OF UNKNOWN DEPTH.

TO REPORT FLOODING...PLEASE RELAY YOUR REPORT TO LOCAL LAW
ENFORCEMENT WHEN YOU CAN DO SO SAFELY.

&&

LAT...LON 3278 11255 3272 11222 3266 11219 3250 11220
      3249 11221 3250 11262

$$

WATERS

1 follow-up statement

039 
WGUS75 KPSR 172047
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
147 PM MST FRI AUG 17 2012

AZC013-172056-
/O.CAN.KPSR.FF.W.0035.000000T0000Z-120817T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
147 PM MST FRI AUG 17 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EXTREME SOUTH
CENTRAL MARICOPA COUNTY...

LAT...LON 3278 11255 3272 11222 3266 11219 3250 11220
      3249 11221 3250 11262

$$

WATERS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 16, 6:16 PM MST	Special Weather Statement	PSR		44 min
Aug 16, 6:43 PM MST	Areal Flood Advisory	PSR	La Paz, Yuma	106 min
Aug 16, 6:50 PM MST	Severe Thunderstorm Warning	PSR	La Paz, Maricopa	40 min
Aug 16, 7:08 PM MST	Flash Flood Warning	PSR	La Paz, Maricopa	2 hr
Aug 16, 8:25 PM MST	Areal Flood Advisory	PSR	La Paz, Maricopa	110 min
Aug 16, 9:02 PM MST	Areal Flood Advisory	PSR	Maricopa	118 min
Aug 16, 11:10 PM MST	Flash Flood Warning	PSR	Maricopa	2 hr
Aug 16, 11:29 PM MST	Areal Flood Advisory	PSR	La Paz	2 hr
Aug 16, 11:41 PM MST	Flash Flood Warning	PSR	Maricopa	3 hr
Aug 17, 12:54 AM MST	Areal Flood Advisory	PSR	La Paz, Yuma	111 min
Aug 17, 1:14 AM MST	Areal Flood Advisory	PSR	Maricopa	2 hr
Aug 17, 2:43 AM MST	Areal Flood Warning	PSR	Maricopa	4 hr
Aug 17, 6:26 AM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Aug 17, 11:16 AM MST	Areal Flood Advisory	PSR	Maricopa	119 min
Aug 17, 11:59 AM MST	Blowing Dust Advisory	PSR		2 hr
Aug 17, 12:25 PM MST	Flash Flood Warning	PSR	Maricopa, Pinal	2 hr
Aug 17, 2:45 PM MST	Blowing Dust Advisory	PSR		91 min

Nearby

Flash Flood Warnings in Arizona, 2012 Every flash flood warning in 2012

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.