Alert archive / Arizona / Flash Flood Warnings in 2003

Flash Flood Warning 12, NWS Phoenix, AZ

August 26, 2003Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Aug 26, 2003, 11:15 PM MST for Maricopa County, Arizona. It was in force for 60 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: Aug 26, 2003, 11:15 PM MST (06:15 UTC)
Expired: Aug 27, 2003, 12:15 AM MST
In force: 60 min
Issued by: NWS Phoenix, AZ
Area: Counties, with a storm outline in the text

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 98 km from the middle of the area, began a volume at 06:18 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 6.3 hours before the alert went out and 67 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 709 J/kg
Mixed-layer CIN: -105 J/kg
Mixed-layer LCL: 1754 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 40 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.

000 
WGUS55 KPSR 270618
FFWPSR
AZC013-270815-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1115 PM MST TUE AUG 26 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 115 AM MST WEDNESDAY

* AT 1115 PM MST...WEATHER SERVICE DOPPLER RADAR INDICATED VERY HEAVY
  RAIN OVER CIRCLE CITY...EXTENDING TO THE EAST TO AROUND LAKE       
  PLEASANT. AN AUTOMATED RAIN GAUGE IN CIRCLE CITY RECORDED NEARLY   
  1.6 INCH OF RAIN SINCE 10:15 PM...AND WEATHER RADAR INDICATES 1.5  
  TO 2.5 INCHES OF RAIN HAS FALLEN FROM CIRCLE CITY TO NEAR LAKE     
  PLEASANT.  

* LOCATIONS IN THE WARNING AREA INCLUDE CIRCLE CITY...               
  MORRISTOWN...HIGHWAY 74...AND ROUTE 60 BETWEEN WITTMAN AND         
  WICKENBURG

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING. 
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. 
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE 
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS 
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY 
AUTOMOBILE. IF YOUR VEHICLE STALLS...ABANDON IT IMMEDIATELY AND SEEK 
HIGHER GROUND. BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO 
RECOGNIZE THE DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING 
IS OBSERVED ACT QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD 
WATERS. DO NOT STAY IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS 
RISING.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
PHOENIX.

LAT...LON 3375 11265 3381 11247 3380 11231 3389 11229
          3394 11248 3384 11272

$$

What forecasters said that day

The local office's own words before this flash flood warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 26, 9:10 PM MST, 2 hours 5 minutes earlier.

Area forecast discussion, Aug 26, 9:10 PM MST, 2 hours 5 minutes before

AZZ020>028-CAZ030>033-271045-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
WEATHER SERVICE PHOENIX AZ
910 PM MST TUE AUG 26 2003

.SYNOPSIS...
A FLOW ALOFT FROM THE EAST THEN SOUTH IS EXPECTED TONIGHT THROUGH
WEDNESDAY. IN ADDITION...MOISTURE FROM FORMER HURRICANE IGNACIO WILL
CONTINUE INCREASING TONIGHT THROUGH WEDNESDAY. THIS MEANS AN
INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT...WITH SOME
HEAVY RAIN POSSIBLE AND COOLER WEATHER THROUGH WEDNESDAY. HIGH
PRESSURE ALOFT FROM THE PACIFIC IS EXPECTED TO BRING A REDUCTION IN
THUNDERSTORMS BY FRIDAY.

.DISCUSSION...
VERY MOIST AIRMASS CONTINUES OVER ALL OF SE CA SW AND SOUTH CENTRAL
AZ. THUNDERSTORMS WERE VERY ACTIVE OVER SE CA THIS AFTERNOON AND
EARLY EVENING WITH SEVERE THUNDERSTORM WATCH. STORMS DIMINISHED AND
SEVERE THUNDERSTORM WATCH WAS CANCELLED. THUNDERSTORMS DEVELOPED
OVER SOUTH CENTRAL HIGHER TERRAIN THIS EVENING AND MOVED INTO THE
ADJCENT DESERTS WITH MANY OUTFLOW BOUNDARES. STORMS EXPECTED TO
CONTINUE OVER SOUTH CENTRAL AZ AND DESERT AREAS INTO TONIGHT AS
OUTFLOW BOUNDARIES INTER ACT AND DEW POINTS REMAIN IN THE MID TO
UPPER 60S. PWATER VALUES OFF PHX 00Z SOUNDING REMAIN HIGH WITH 1.8
INCHES. THUS...WITH THIS VERY MOIST AIRMASS THESE STORMS WILL
CONTINUE TO PRODUCE SOME HEAVY RAINS. THIS WILL KEEP VALID A FLASH
FLOOD WATCH FOR SOUTH CENTRAL AZ THROUGH WED. CHANCE OF
THUNDERSTORMS WILL ALSO CONTINUE OVER SW AZ SE CA TONIGHT TOO...BUT
WILL ALLOW FLASH FLOOD WATCH FOR SW AZ SE CA TO EXPIRE AT 05Z. NEW
ETA KEEPS UPPER HIGH TO THE EAST OF AZ WITH THE REMAINS OF IGNACIO
MOVING NORTH UP THE BAJA PENNSULIA. THIS WILL KEEP A SOUTHERLY FLOW
AT BOTH LOW AND MID LEVELS OVER THE REGION AT LEAST THROUGH MID WEEK
KEEPING THE AIRMASS MOIST FOR CHANCE OF SHOWERS AND THUNDERSTORMS
THROUGH WED NIGHT OVER THE REGION...AND INTO THE LATER PART OF THE
WEEK. DKS

.PSR...FLASH FLOOD WATCH FOR SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA ZONES 20...21...25...26...30...31...32...AND 33
YUMA COUNTY...LA PAZ COUNTY...IMPERIAL COUNTY AND EASTERN
RIVERSIDE COUNTY INCLUDING ALL OF JOSHUA TREE NATIONAL PARK
10 PM MST THIS EVENING OR 27/0500 GMT.

FLASH FLOOD WATCH FOR SOUTH-CENTRAL ARIZONA ZONES
22...23...24...27...AND 28 MARICOPA COUNTY...NORTH CENTRAL AND
NORTHWEST PINAL COUNTY AND SOUTHERN GILA COUNTY THROUGH WEDNESDAY.

Hazardous weather outlook, Aug 26, 6:00 AM MST, 17 hours 15 minutes before

AZZ020>028-CAZ030>033-270100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
600 AM MST TUE AUG 26 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND
SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY

THE AIRMASS OVER ARIZONA AND SOUTHEAST CALIFORNIA REMAINS VERY
MOIST AND UNSTABLE...AND ADDITIONAL MOISTURE IS EXPECTED TO MOVE
INTO ARIZONA FROM FORMER HURRICANE IGNACIO. THUS SCATTERED
THUNDERSTORMS ARE FORECAST TO DEVELOP TODAY...MAINLY IN THE LATE
AFTERNOON AND EVENING HOURS. HEAVY RAIN IS POSSIBLE WITH ANY
THUNDERSTORM...AS WELL AS SOME BLOWING DUST AND STRONG GUSTY WINDS.
HEAVY RAIN COULD LEAD TO FLOODING OF ROADS...WASHES AND OTHER LOW
SPOTS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THERE WILL BE AN INCREASED THREAT FOR SHOWERS AND THUNDERSTORMS WITH
HEAVY RAIN WEDNESDAY AND WEDNESDAY NIGHT...ESPECIALLY OVER
SOUTH-CENTRAL ARIZONA...AS MOISTURE FROM IGNACIO CONTINUES TO SPREAD
INTO ARIZONA. STAY AWAY FROM FLOODED AREAS INCLUDING ROADWAYS AND
WASHES...AND BE PREPARED TO MOVE TO HIGHER GROUND SHOULD A WARNING
BE ISSUED.

.INSTRUCTIONS TO SPOTTERS...
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

BRECKENRIDGE

In the hours before

Special weather statement, Aug 26, 6:11 PM MST, 5 hours 4 minutes before

AZZ020-021-025-026-CAZ030>033-270140-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
611 PM MST TUE AUG 26 2003

...SEVERE THUNDERSTORM WATCH NUMBER 896 WHICH INCLUDES WESTERN
ARIZONA HAS BEEN CANCELED...

THE SEVERE THUNDERSTORM WATCH AREA WHICH INCLUDED LA PAZ AND
YUMA COUNTIES HAS BEEN CANCELLED. WEATHER CONDITIONS WHICH WERE
FAVORABLE FOR THE DEVELOPMENT OF SEVERE THUNDERSTORMS HAS NOW
DIMINISHED...SO THE THREAT OF SEVERE THUNDERSTORMS HAS ALSO
DIMINISHED.

EVEN THOUGH THE SEVERE THUNDERSTORM WATCH HAS BEEN CANCELLED...
THERE STILL EXISTS THE CHANCE FOR SHOWERS AND THUNDERSTORMS
THROUGHOUT TONIGHT AND WEDNESDAY.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 26, 6:00 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	60 min
Aug 26, 6:55 PM MST	Flash Flood Warning	PSR	Gila	65 min
Aug 27, 9:36 AM MST	Flash Flood Warning	PSR	La Paz, Maricopa	3 hr

Nearby

Flash Flood Warnings in Arizona, 2003 Every flash flood warning in 2003

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.