Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 55, NWS Phoenix, AZ

August 29, 2012La Paz County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 29, 2012, 4:28 PM MST for La Paz 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 29, 2012, 4:28 PM MST (23:28 UTC)
Expired
Aug 29, 2012, 6:30 PM MST
In force
2 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 169 km from the middle of the area, began a volume at 23:30 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 12:00Z, 11.5 hours before the alert went out and 218 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 12:00Z on 2012-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 150 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 12:00Z on 2012-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -20 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
150 J/kg
Mixed-layer CIN
-335 J/kg
Mixed-layer LCL
2256 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-20 m²/s²
0-3 km storm-relative helicity
-36 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.

261 
WGUS55 KPSR 292328
FFWPSR
AZC012-300130-
/O.NEW.KPSR.FF.W.0055.120829T2328Z-120830T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
428 PM MST WED AUG 29 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 630 PM MST

* AT 421 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
VERY HEAVY RAIN THAT WILL CAUSE FLASH FLOODING. RADAR INDICATED THAT 
OVER TWO INCHES OF RAIN FELL SINCE 330 PM IN THE AREA WEST OF 
BOUSE...NEAR THE INTERSECTION OF HIGHWAYS 95 AND 72. THE AREA OF 
GREATEST CONCERN IS HIGHWAY 95 NORTH OF INTERSTATE 10 AND WEST OF 
BOUSE.

* 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...

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.

&&

LAT...LON 3408 11433 3407 11406 3381 11408 3381 11437

$$

CB
2 follow-up statements
113 
WGUS75 KPSR 300002
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
502 PM MST WED AUG 29 2012

AZC012-300130-
/O.CON.KPSR.FF.W.0055.000000T0000Z-120830T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PAZ AZ-
502 PM MST WED AUG 29 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MST FOR
CENTRAL LA PAZ COUNTY...

AT 454 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED 
SCATTERED THUNDERSTORMS BETWEEN BOUSE AND POSTON...PRODUCING LOCALLY 
HEAVY RAIN THAT WILL LIKELY CAUSE FLASH FLOODING. THE STORMS HAVE 
BEEN DISSIPATING SINCE 430 PM BUT RAINFALL RATES IN THE AREA STILL 
WERE IN EXCESS OF ONE INCH PER HOUR. THE HEAVIEST RAIN HAS FALLEN 
JUST TO THE EAST OF HIGHWAY 95...NEAR THE INTERSECTION OF HIGHWAY 72 
TO THE WEST OF BOUSE. MOTORISTS ON HIGHWAY 95 NORTH OF INTERSTATE 10 
SHOULD BE ALERT FOR WATER OVER THE ROAD AND SHOULD DRIVE WITH 
EXTREME CAUTION.

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 3408 11433 3407 11406 3381 11408 3381 11437

$$

CB
810 
WGUS75 KPSR 300121
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
621 PM MST WED AUG 29 2012

AZC012-300130-
/O.CON.KPSR.FF.W.0055.000000T0000Z-120830T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
LA PAZ AZ-
621 PM MST WED AUG 29 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM MST FOR
CENTRAL LA PAZ COUNTY...

AT 613 PM MST... STORMS IN THE FLASH FLOOD WARNING AREA...WHICH IS 
PRIMARILY THE AREA NEAR THE INTERSECTION OF HIGHWAY 95 AND HIGHWAY 
72...HAVE DISSIPATED. LITTLE RAIN HAS FALLEN IN THE WARNING AREA 
SINCE 6 PM. THE WARNING WILL BE ALLOWED TO EXPIRE AT 630 PM. NO 
REPORTS OF FLOODING HAVE BEEN RECEIVED AT THIS TIME.

THERE MAY STILL BE WATER OVER AREA ROADS ACROSS WEST CENTRAL LA PAZ 
COUNTY...ESPECIALLY HIGHWAY 95 NORTH OF INTERSTATE 10. MOTORISTS 
THIS EVENING SHOULD BE ALERT FOR WATER OVER ROADS AND SHOULD DRIVE 
WITH CAUTION.

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 3408 11433 3407 11406 3381 11408 3381 11437

$$

CB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 3:13 PM MSTSevere Thunderstorm WarningPSRLa Paz62 min
Aug 29, 3:42 PM MSTAreal Flood AdvisoryPSRLa Paz3 hr
Aug 29, 3:42 PM MSTSpecial Weather StatementPSRLa Paz48 min
Aug 29, 4:00 PM MSTSevere Thunderstorm WarningPSRLa Paz55 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.