Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 68, NWS Phoenix, AZ

September 4, 2012Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 4, 2012, 10:14 PM MST for Maricopa County, Arizona. It was in force for 72 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Sep 4, 2012, 10:14 PM MST (05:14 UTC)
Expired
Sep 4, 2012, 11:26 PM MST
In force
72 min
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 138 km from the middle of the area, began a volume at 05:13 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

Phoenix, AZ (KPSR), launched 00:00Z, 5.2 hours before the alert went out and 125 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 2012-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 386 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 2012-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 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
386 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
2024 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
-20 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.

787 
WGUS55 KPSR 050514
FFWPSR
AZC013-050715-
/O.NEW.KPSR.FF.W.0068.120905T0514Z-120905T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1014 PM MST TUE SEP 4 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 1215 AM MST

* AT 1011 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS
  DETECTED THUNDERSTORMS WITH VERY HEAVY RAIN CROSSING HIGHWAY 85
  SOUTH OF GILA BEND. MOVEMENT WAS SOUTHEAST AT 15 MPH.

* THE STORMS HAVE PRODUCED OVER 2 INCHES OF RAIN SINCE 900 PM...WITH
  AN ADDITIONAL 1 TO 2 INCHES POSSIBLE. RUNOFF FROM THIS HEAVY RAIN
  WILL AFFECT HIGHWAY 85 BETWEEN GILA BEND AND AJO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 3275 11310 3281 11275 3250 11269 3250 11307

$$

WOODALL
2 follow-up statements
298 
WGUS75 KPSR 050550
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
1050 PM MST TUE SEP 4 2012

AZC013-050715-
/O.CON.KPSR.FF.W.0068.000000T0000Z-120905T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
1050 PM MST TUE SEP 4 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM MST FOR
EXTREME SOUTHWESTERN MARICOPA COUNTY...

AT 1046 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED 
THUNDERSTORMS WITH VERY HEAVY RAIN ALONG AND WEST OF HIGHWAY 85 
SOUTH OF GILA BEND.

UP TO 3 INCHES OF RAIN HAS FALLEN ALONG AND WEST OF HIGHWAY 85 SINCE 
945 PM. RUNOFF FROM THE HEAVY RAIN WILL AFFECT HIGHWAY 85 BETWEEN 
GILA BEND AND AJO...ESPECIALLY LOW LYING AREAS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE EXTRA CAUTIOUS AT NIGHT WHEN FLOODING IS HARDER TO SEE. 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 3275 11310 3281 11275 3250 11269 3250 11307

$$

WOODALL
281 
WGUS75 KPSR 050626
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
1126 PM MST TUE SEP 4 2012

AZC013-050635-
/O.CAN.KPSR.FF.W.0068.000000T0000Z-120905T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
1126 PM MST TUE SEP 4 2012

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

HEAVY RAIN HAS ENDED ACROSS SOUTHWEST MARICOPA COUNTY. RUNOFF FROM 
PREVIOUS STORMS WILL CONTINUE INTO THE EARLY MORNING HOURS HOWEVER 
FLASH FLOODING IS NO LONGER ANTICIPATED. CONTINUE TO USE CAUTION IF 
TRAVELING OVERNIGHT AND DO NOT ENTER ANY AREAS WHERE WATER IS 
FLOWING OVER THE ROADWAY. 

LAT...LON 3275 11310 3281 11275 3250 11269 3250 11307

$$

LEINS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 5:25 PM MSTSpecial Weather StatementPSRMaricopa50 min
Sep 4, 6:01 PM MSTAreal Flood AdvisoryPSRGila119 min
Sep 4, 6:42 PM MSTSpecial Weather StatementPSRMaricopa33 min
Sep 4, 7:06 PM MSTAreal Flood AdvisoryPSRMaricopa114 min
Sep 4, 7:06 PM MSTAreal Flood AdvisoryPSRLa Paz, Maricopa114 min
Sep 4, 8:30 PM MSTBlowing Dust AdvisoryPSR90 min
Sep 4, 8:35 PM MSTAreal Flood AdvisoryPSRMaricopa, Yuma115 min
Sep 4, 8:45 PM MSTAreal Flood AdvisoryPSRPinal2 hr
Sep 4, 9:09 PM MSTFlash Flood WarningPSRMaricopa2 hr
Sep 4, 9:42 PM MSTAreal Flood AdvisoryPSRMaricopa2 hr
Sep 5, 3:27 PM MSTSpecial Weather StatementPSR33 min
Sep 5, 4:23 PM MSTSpecial Weather StatementPSR22 min
Sep 5, 4:53 PM MSTSpecial Weather StatementPSR37 min

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.