Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 77, NWS Phoenix, AZ

September 11, 2012La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 11, 2012, 1:18 AM MST for La Paz County, Arizona. It was in force for 3 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
Sep 11, 2012, 1:18 AM MST (08:18 UTC)
Expired
Sep 11, 2012, 4:15 AM MST
In force
3 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 173 km from the middle of the area, began a volume at 08:20 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, 8.3 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-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2012-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 179 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 2012-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
179 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
2111 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
27 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.

399 
WGUS55 KPSR 110818
FFWPSR
AZC012-111115-
/O.NEW.KPSR.FF.W.0077.120911T0818Z-120911T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
118 AM MST TUE SEP 11 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EAST CENTRAL LA PAZ COUNTY IN WEST CENTRAL ARIZONA...

* UNTIL 415 AM MST

* AT 112 AM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING. STREAM GAGES ALONG 
THE CENTENNIAL WASH IN WENDEN INDICATE WATER HAS RISEN TO A DEPTH OF 
NEARLY 3 FEET AND WITH ADDITIONAL RAINFALL EXPECTED...THE WATER 
LEVEL WILL CONTINUE TO RISE AND CAUSE FLOODING IN AND NEAR WENDEN. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
WENDEN...SALOME

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.

&&

LAT...LON 3360 11361 3380 11365 3393 11338 3385 11340
      3357 11345

$$

LEINS
2 follow-up statements
065 
WGUS75 KPSR 110923
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
223 AM MST TUE SEP 11 2012

AZC012-111115-
/O.CON.KPSR.FF.W.0077.000000T0000Z-120911T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PAZ AZ-
223 AM MST TUE SEP 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 AM MST FOR EAST
CENTRAL LA PAZ COUNTY...

AT 218 AM MST...RAINFALL WAS ENDING ACROSS LA PAZ COUNTY. 
HOWEVER...STREAM GAGES CONTINUE TO INDICATE ELEVATED FLOW AROUND 3 
FEET DEEP IN THE CENTENNIAL WASH NEAR WENDEN. THE FLOW IS EXPECTED 
TO CONTINUE UNTIL AT LEAST 4 AM BEFORE GRADUALLY RECEDING. LOW LYING 
AREAS NEAR CENTENNIAL WASH WILL LIKELY SEE FLOODING BEFORE THEN. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WENDEN AND
SALOME

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.

&&

LAT...LON 3360 11361 3380 11365 3393 11338 3385 11340
      3357 11345

$$

LEINS
146 
WGUS75 KPSR 111108
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
408 AM MST TUE SEP 11 2012

AZC012-111117-
/O.EXP.KPSR.FF.W.0077.000000T0000Z-120911T1115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PAZ AZ-
408 AM MST TUE SEP 11 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 415 AM MST FOR EAST CENTRAL
LA PAZ COUNTY...

RUNOFF FROM PREVIOUS STORMS WILL CONTINUE THIS MORNING...BUT THE 
THREAT FOR FLASH FLOODING HAS ENDED. CONTINUE TO USE CAUTION IF 
TRAVELING THIS MORNING AND YOU ENCOUNTER FLOODED AREAS. DO NOT CROSS 
FLOODED ROADWAYS. 

LAT...LON 3360 11361 3380 11365 3393 11338 3385 11340
      3357 11345

$$

LEINS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 10, 6:38 PM MSTSpecial Weather StatementPSR52 min
Sep 10, 7:34 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal116 min
Sep 10, 8:33 PM MSTAreal Flood AdvisoryPSRMaricopa117 min
Sep 10, 9:26 PM MSTFlash Flood WarningPSRMaricopa79 min
Sep 10, 9:59 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal2 hr
Sep 10, 10:14 PM MSTAreal Flood AdvisoryPSRMaricopa, Pinal2 hr
Sep 10, 10:45 PM MSTFlash Flood WarningPSRMaricopa60 min
Sep 10, 11:03 PM MSTAreal Flood AdvisoryPSRMaricopa117 min
Sep 10, 11:12 PM MSTAreal Flood AdvisoryPSRLa Paz, Yuma5 hr
Sep 10, 11:25 PM MSTFlash Flood WarningPSRMaricopa110 min
Sep 11, 1:05 AM MSTAreal Flood AdvisoryPSRMaricopa3 hr
Sep 11, 3:42 AM MSTFlash Flood WatchPSR11 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.