Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 38, NWS Phoenix, AZ

August 18, 2012Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 18, 2012, 3:02 PM MST for Maricopa 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
Aug 18, 2012, 3:02 PM MST (22:02 UTC)
Expired
Aug 18, 2012, 6:00 PM MST
In force
3 hr
Issued by
NWS Phoenix, AZ
Area
Storm-based polygon
Flood severity
None

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 71 km from the middle of the area, began a volume at 22:04 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, 10.0 hours before the alert went out and 69 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 2012-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 941 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 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 2012-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 54 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
941 J/kg
Mixed-layer CIN
-63 J/kg
Mixed-layer LCL
1133 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
54 m²/s²
0-3 km storm-relative helicity
59 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.

752 
WGUS55 KPSR 182202
FFWPSR
AZC013-190000-
/O.NEW.KPSR.FF.W.0038.120818T2202Z-120819T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
302 PM MST SAT AUG 18 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EXTREME NORTHEASTERN MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA...
  THIS INCLUDES SYCAMORE CREEK...SUNFLOWER...

* UNTIL 500 PM MST

* AT 255 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED   
  HEAVY RAIN OVER THE SUNFLOWER BURN AREA. STORMS IN THE AREA HAVE   
  ALREADY PRODUCED OVER ONE HALF INCH OF RAINFALL ACROSS THE 
  NORTHERN PORTIONS OF THE BURN AREA. THE RAIN WILL PRODUCE HIGH 
  WATER IN CREEKS AND WASHES ACCOMPANIED BY MUD...ROCKS...AND 
  DEBRIS.

* FLASH FLOODING OF THE SYCAMORE CREEK DRAINAGE IS IMMINENT AND WILL
  IMPACT THE COMMUNITY OF SUNFLOWER...AS WELL AS LOW WATER CROSSINGS
  OF FOREST ROADS AND TRAILS. THIS INCLUDES FOREST ROAD 22 SOUTH OF
  HIGHWAY 87...THE ARIZONA TRAIL...AND BOULDER CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE BANKS OF SYCAMORE CREEK OR OTHER NEARBY DRAINAGE
AREAS MOVE IMMEDIATELY TO HIGHER GROUND. DO NOT DRIVE YOUR VEHICLE
INTO AREAS WHERE WATER COVERS THE ROAD. TURN AROUND DONT DROWN.

LIFE-THREATENING FLOODING OF CREEKS...ROADS AND NORMALLY DRY WASHES
IS LIKELY. THE HEAVY RAINS WILL TRIGGER MUD AND DEBRIS FLOWS...AND
ROCKSLIDES IN STEEP TERRAIN...ESPECIALLY NEAR THE BURN AREA.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT.


&&

LAT...LON 3398 11153 3399 11145 3382 11145 3381 11153

$$

NOLTE
4 follow-up statements
855 
WGUS75 KPSR 182226
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
326 PM MST SAT AUG 18 2012

AZC013-190000-
/O.CON.KPSR.FF.W.0038.000000T0000Z-120819T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
326 PM MST SAT AUG 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM MST FOR
EXTREME NORTHEASTERN MARICOPA COUNTY...

AT 313 PM MST...WEATHER RADAR DETECTED SEVERAL LARGE THUNDERSTORMS
WITH HEAVY RAIN REDEVELOPING IN THE SUNFLOWER BURN AREA...IN 
OTHER TRIBUTARIES FEEDING INTO THE SYCAMORE WASH.

THIS IS A DANGEROUS SITUATION IN WHICH FLASH FLOODING IS LIKELY. IT 
MAY TAKE ABOUT ONE HOUR TO ONE AND ONE HALF HOURS FOR FLASH FLOODING 
TO MOVE PAST THE SMALL RANCHES ALONG THE SYCAMORE WASH...DOWN STREAM 
FROM THE SUNFLOWER BURN AREA.


LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SYCAMORE
CREEK

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE BANKS OF SYCAMORE CREEK OR OTHER NEARBY DRAINAGE
AREAS MOVE IMMEDIATELY TO HIGHER GROUND. DO NOT DRIVE YOUR VEHICLE
INTO AREAS WHERE WATER COVERS THE ROAD. TURN AROUND DONT DROWN.

LIFE-THREATENING FLOODING OF CREEKS...ROADS AND NORMALLY DRY WASHES
IS LIKELY. THE HEAVY RAINS WILL TRIGGER MUD AND DEBRIS FLOWS...AND
ROCKSLIDES IN STEEP TERRAIN...ESPECIALLY NEAR THE BURN AREA.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT.

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 3398 11153 3399 11145 3382 11145 3381 11153

$$

HV
217 
WGUS75 KPSR 182301
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
401 PM MST SAT AUG 18 2012

AZC013-190000-
/O.CON.KPSR.FF.W.0038.000000T0000Z-120819T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
401 PM MST SAT AUG 18 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM MST FOR
EXTREME NORTHEASTERN MARICOPA COUNTY...

AT 346 PM MST...THUNDERSTORMS WITH HEAVY RAIN HAVE WEAKENED AND 
MOVED WEST OF THE SUNFLOWER BURN AREA. HOWEVER...VERY HEAVY RAIN HAS 
FALLEN OVER THE BURN AREA AND ITS TRIBUTARIES FEEDING INTO THE 
MAINSTREAM SYCAMORE CREEK.  ONE RIVER GAGE ALONG THE SYCAMORE WASH 
JUST OUTSIDE THE BURN AREA RECORDED A WALL OF WATER AND FLOODING 4 
TO 5 FEET DEEP...FLOWING DOWNSTREAM TOWARD THE SMALL RANCHES ALONG 
SYCAMORE CREEK...AND TOWARD THE TOWN OF SUNFLOWER.

ALTHOUGH RAINFALL HAD DIMINISHED AT 346 PM...IT WILL TAKE SEVERAL 
HOURS FOR WATER TO WORK ITS WAY DOWNSTREAM IN THE SYCAMORE WASH 
MAKING FLASH FLOODING LIKELY THROUGH 5 PM.  

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO SYCAMORE 
CREEK.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE BANKS OF SYCAMORE CREEK OR OTHER NEARBY DRAINAGE
AREAS MOVE IMMEDIATELY TO HIGHER GROUND. DO NOT DRIVE YOUR VEHICLE
INTO AREAS WHERE WATER COVERS THE ROAD. TURN AROUND DONT DROWN.

LIFE-THREATENING FLOODING OF CREEKS...ROADS AND NORMALLY DRY WASHES
IS LIKELY. THE HEAVY RAINS WILL TRIGGER MUD AND DEBRIS FLOWS...AND
ROCKSLIDES IN STEEP TERRAIN...ESPECIALLY NEAR THE BURN AREA.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT.

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 3398 11153 3399 11145 3382 11145 3381 11153

$$

HV
248 
WGUS55 KPSR 190000
FFWPSR
AZC013-190100-
/O.EXT.KPSR.FF.W.0038.000000T0000Z-120819T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
500 PM MST SAT AUG 18 2012

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  EXTREME NORTHEASTERN MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA...
  THIS INCLUDES SYCAMORE CREEK DOWNSTREAM TO THE TOWN OF
  SUNFLOWER...

* UNTIL 600 PM MST

* AT 447 PM MST...ALTHOUGH HEAVY THUNDERSTORM RAINS HAVE ENDED OVER 
THE SUNFLOWER BURN AREA...A MEASURED FLOW OF 4 TO 5 FEET OF WATER 
HAS YET TO REGISTER ON SYCAMORE CREEK RIVER GAGE AT HIGHWAY 87. 
THEREFORE FLOOD OR FLASH FLOODING IS STILL WORKING ITS WAY 
DOWNSTREAM IN SYCAMORE CREEK TOWARD THE TOWN OF SUNFLOWER.  

THE FLASH FLOOD WARNING FOR SYCAMORE CREEK WILL BE EXTENDED UNTIL 6 
PM. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE NEAR THE BANKS OF SYCAMORE CREEK OR OTHER NEARBY DRAINAGE
AREAS MOVE IMMEDIATELY TO HIGHER GROUND. DO NOT DRIVE YOUR VEHICLE
INTO AREAS WHERE WATER COVERS THE ROAD. TURN AROUND DONT DROWN.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT.

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.

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

&&

LAT...LON 3398 11153 3399 11145 3382 11145 3381 11153

$$

HV
786 
WGUS75 KPSR 190102
FFSPSR

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
602 PM MST SAT AUG 18 2012

AZC013-190107-
/O.EXP.KPSR.FF.W.0038.000000T0000Z-120819T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MARICOPA AZ-
602 PM MST SAT AUG 18 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 600 PM MST FOR EXTREME
NORTHEASTERN MARICOPA COUNTY...

THE FLASH FLOOD WARNING ISSUED EARLIER FOR THE CREEKS AND WASHES IN 
THE SUNFLOWER BURN AREA...AND THE MAINSTREAM SYCAMORE CREEK WAS 
ALLOWED TO EXPIRE AT 6 PM.

A RIVER GAGE ON SYCAMORE CREEK MEASURED RUNOFF 4 TO 5 FEET DEEP 
WHICH WORKED ITS WAY DOWNSTREAM TOWARD THE TOWN OF SUNFLOWER. THERE 
HAS BEEN NO FEEDBACK OR INFORMATION FROM RANCHERS OR OTHER PEOPLE IN 
IN THE AREA AS TO THE IMPACT OF FLOODING ALONG SYCAMORE CREEK...SO
THE FLASH FLOOD WARNING WAS ALLOWED TO EXPIRE.


LAT...LON 3398 11153 3399 11145 3382 11145 3381 11153

$$

HV

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.