Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 31, NWS Phoenix, AZ

July 31, 2012Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Jul 31, 2012, 6:21 PM MST for Maricopa County, Arizona. It was in force for 114 min. 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 31, 2012, 6:21 PM MST (01:21 UTC)
Expired
Jul 31, 2012, 8:15 PM MST
In force
114 min
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 01:24 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

TimeReportWhereRemark
Jul 31, 6:30 PM MSTFLASH FLOOD1 Ne Anthem, AZANTHEM RECREATION PARK FLOODED.

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, 1.4 hours before the alert went out and 52 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-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2012-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 744 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2012-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 61 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
744 J/kg
Mixed-layer CIN
-53 J/kg
Mixed-layer LCL
1738 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
61 m²/s²
0-3 km storm-relative helicity
118 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.

695 
WGUS55 KPSR 010121
FFWPSR
AZC013-010315-
/O.NEW.KPSR.FF.W.0031.120801T0121Z-120801T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
621 PM MST TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA...
  THIS INCLUDES NEW RIVER...

* UNTIL 815 PM MST

* AT 614 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
THUNDERSTORMS PRODUCING VERY HEAVY RAIN THAT WILL CAUSE FLASH 
FLOODING. TRAINED SPOTTERS IN ANTHEM REPORT ONE AND ONE HALF INCHES 
OF RAIN HAVE FALLEN IN THE LAST 45 MINUTES. CURB TO CURB STREET 
FLOODING HAS BEEN REPORT IN ANTHEM...AND RAIN CONTINUES TO FALL. 
RUNOFF WILL CONTINUE TO FLOW INTO DEADMAN WASH AND SKUNK CREEK...AND 
PONDING OF WATER WILL OCCUR ON LOCAL ROADWAYS IN THE AREA AND ON 
INTERSTATE 17. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOST FLOOD DEATHS OCCUR IN MOTORIZED VEHICLES. WHEN ENCOUNTERING 
FLOODED ROADS...MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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

&&

LAT...LON 3393 11219 3392 11209 3379 11209 3379 11221

$$

MEYERS
1 follow-up statement
988 
WGUS75 KPSR 010209
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
709 PM MST TUE JUL 31 2012

AZC013-010315-
/O.CON.KPSR.FF.W.0031.000000T0000Z-120801T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
709 PM MST TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM MST FOR NORTH
CENTRAL MARICOPA COUNTY INCLUDING THE COMMUNITY OF ANTHEM...

AT 656 PM MST...TRAINED WEATHER SPOTTERS REPORTED A THUNDERSTORM 
PRODUCING VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING. THE HEAVY 
RAIN AND FLASH FLOODING WERE PRIMARILY AFFECTING THE COMMUNITY OF 
ANTHEM. SEVERAL TRAINED SPOTTERS REPORTED FROM ONE TO TWO INCHES OF 
RAIN WITHIN ONE HOUR IN THE ANTHEM AREA...AND RADAR RAINFALL 
ESTIMATED BETWEEN TWO AND THREE INCHES OF RAIN IN THE WARNING AREA 
SINCE 6 PM. HEAVY RAIN MAY HAVE CAUSED A ROOF COLLAPSE AT THE ANTHEM 
SAFEWAY ACCORDING TO THE LOCAL FIRE DEPARTMENT.

FLASH FLOODING WAS ALSO OCCURRING ALONG THE DEADMAN WASH FROM ANTHEM 
SOUTHWESTWARD ACROSS INTERSTATE 17 TO THE CAREFREE HIGHWAY.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO NEW RIVER 
AND INTERSTATE 17.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WARNING MEANS THAT PEOPLE ALONG THE BANKS OF WASHES AND
CREEKS SHOULD MOVE TO HIGHER GROUND IMMEDIATELY. NORMALLY DRY WASHES
AND STREAMS WILL SUDDENLY HAVE RUNNING WATER AND MAKE UNBRIDGED
CROSSINGS IMPASSABLE. STREETS...UNDERPASSES...AND LOW SPOTS WILL
BECOME INUNDATED MAKING DRIVING HAZARDOUS IN THE WARNED AREA.

MOST FLOOD DEATHS OCCUR IN MOTORIZED VEHICLES. WHEN ENCOUNTERING
FLOODED ROADS...MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

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

&&

LAT...LON 3393 11219 3392 11209 3379 11209 3379 11221

$$

CB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 5:02 PM MSTSpecial Weather StatementPSR28 min
Jul 31, 5:10 PM MSTSevere Thunderstorm WarningPSRMaricopa43 min
Jul 31, 5:40 PM MSTSevere Thunderstorm WarningPSRMaricopa65 min
Jul 31, 5:56 PM MSTAreal Flood AdvisoryPSRMaricopa109 min
Jul 31, 8:08 PM MSTAreal Flood WarningPSRMaricopa10 hr

Nearby

Flash Flood Warnings in Arizona, 2012Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.