Alert archive / Arizona / Flash Flood Warnings in 2003

Flash Flood Warning 20, NWS Phoenix, AZ

September 9, 2003Gila County, Maricopa County, Arizona

NWS Phoenix, AZ issued this flash flood warning at Sep 9, 2003, 3:05 AM MST for Gila County, Maricopa County, Arizona. It was in force for 55 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 9, 2003, 3:05 AM MST (10:05 UTC)
Expired
Sep 9, 2003, 4:00 AM MST
In force
55 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

Counties Gila County, AZ, Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 82 km from the middle of the area, began a volume at 10:06 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, 10.1 hours before the alert went out and 104 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 2003-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1296 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2003-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 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
1296 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
2324 m above ground
0-6 km bulk shear
1 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
1 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 091010
FFWPSR
AZC007-013-091200-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
305 AM MST TUE SEP 9 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING BETWEEN LAKE ROOSEVELT AND THE CITY OF GLOBE...
  CENTRAL GILA COUNTY IN EAST CENTRAL ARIZONA
  EXTREME EAST CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA

* UNTIL 500 AM MST

* AT 256 AM MST...WEATHER RADAR DETECTED EXTREMELY HEAVY RAIN...
  ON THE ORDER OF 1 TO 2 INCHES PER HOUR...BETWEEN ROOSEVELT LAKE
  AND THE CITY OF GLOBE. HEAVY RAIN FALLING IN ROUGH TERRAIN WILL
  LIKELY LEAD TO FLASH FLOODING OF NORMALLY DRY WASHES...ESPECIALLY
  THOSE DRAINING ACROSS HIGHWAYS 88 AND 188 BETWEEN GLOBE AND
  LAKE ROOSEVELT. 

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK AND MUDSLIDES IN STEEP TERRAIN.

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.

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

LAT...LON 3309 11087 3347 11104 3347 11120 3374 11144
          3381 11116 3372 11095 3370 11075 3381 11067
          3386 11044 3367 11012

$$

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 Sep 9, 2:45 AM MST, 20 minutes earlier.

Area forecast discussion, Sep 9, 2:45 AM MST, 20 minutes before
AZZ020>028-CAZ030>033-091745-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
245 AM MST TUE SEP 9 2003

.SYNOPSIS...
A SERIES OF PACIFIC LOW PRESSURE SYSTEMS...ALONG WITH INCREASING
MONSOON MOISTURE...WILL RESULT IN SCATTERED SHOWERS AND THUNDER
STORMS OVER PARTS OF SOUTHWEST AND SOUTH CENTRAL ARIZONA TODAY.
STRONG THUNDERSTORM WINDS...HAIL...AND VERY HEAVY RAIN ARE POSSIBLE
...ALONG WITH THE POTENTIAL FOR LOCAL FLOODING IN SOUTH CENTRAL
ARIZONA TODAY. THE CHANCE FOR SHOWERS WILL CONTINUE OVER SOUTH
CENTRAL ARIZONA TONIGHT AND WEDNESDAY...WITH CLEARING OVER SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA. HIGH PRESSURE AND A MUCH DRIER
AIRMASS WILL PRODUCE MOSTLY CLEAR SKIES THURSDAY...FRIDAY...AND
THE WEEKEND.

.DISCUSSION...
THE PATTERN WAS GETTING INTERESTING THIS MORNING AS A VERY ENERGETIC
DIFLUENT FLOW ALOFT WAS EVOLVING OVER CENTRAL AZ. AT THE SAME TIME
...LOW LEVEL WINDS HAD FINALLY BACKED OVER SOUTH CENTRAL ARIZONA
IMPORTING LOTS OF MOISTURE INTO THE AREA. AFTER 06Z A STATIONARY
MCS DEVELOPED JUST EAST OF PHOENIX...OVER THE MOUNTAINS EXTENDING TO
ROOSEVELT LAKE...WHERE MESO-CYCLONES AND EXTREMELY HEAVY RAIN HAD
FALLEN. SEVERAL SEVERE THUNDERSTORM WARNINGS AND A FLASH FLOOD
WARNING WAS STILL IN AFFECT AT THE TIME OF THIS WRITING (0935Z).

THE SECOND IN A SERIES OF SHORTWAVES WAS ALSO APPROACHING CENTRAL
ARIZONA THIS MORNING. INCREASING DYNAMICS...MOISTURE...AND GOOD
VERTICAL SHEAR PROFILES WILL INCREASE OVER SOUTH CENTRAL ARIZONA
TODAY...INCLUDING PHOENIX...MAINLY BETWEEN 12Z AND 21Z. THE
POTENTIAL FOR FAST MOVING SEVERE THUNDERSTORMS...WITH POTENTIAL FOR
MESO CYCLONES AND LARGE HAIL WITH HEAVY RAIN ARE POSSIBLE TODAY.
THE CURRENT FLASH FLOOD WATCH FOR PARTS OF SOUTH CENTRAL AZ WILL
CONTINUE THROUGH 03Z WED.

FAST DIFLUENT FLOW ALOFT WILL CONTINUE THROUGH TUESDAY EVENING...
WITH A TERTIARY SHORTWAVE (THE LAST IN THE SERIES)...FORECAST TO
MOVE THROUGH WEDNESDAY MORNING. A MUCH DRIER POST FRONTAL AIRMASS
WILL SPREAD ACROSS CENTRAL ARIZONA LATER WEDNESDAY...SO THE CHANCE
FOR SHOWERS AND THUNDERSTORMS WILL DECREASE DURING THE DAY.

A MUCH DRIER AIRMASS IS EXPECTED THURSDAY THROUGH MONDAY FOR
MOSTLY SUNNY SKIES WITH NEAR NORMAL TEMPERATURES. NO UPDATES TO
EXTENDED PERIOD. VASQUEZ.

.PSR...FLASH FLOOD WATCH FOR SOUTH-CENTRAL ARIZONA ZONES 22...23...
       24...27...AND 28...MARICOPA COUNTY...INCLUDING THE GREATER
       PHOENIX AREA...NORTHWEST AND NORTH-CENTRAL PINAL
       COUNTY...AND SOUTHERN GILA COUNTY UNTIL 03Z..
Hazardous weather outlook, Sep 8, 6:00 AM MST, 21 hours 5 minutes before
AZZ020>028-CAZ030>033-090100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
600 AM MST MON SEP 8 2003

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

.DAY ONE...TODAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A PACIFIC WEATHER SYSTEM MOVING THROUGH THE WESTERN STATES WILL
EXTEND INTO ARIZONA TUESDAY...PROVIDING AN INCREASING CHANCE FOR
STRONG THUNDERSTORMS...MAINLY IN SOUTH CENTRAL ARIZONA DURING THE
AFTERNOON AND EVENING HOURS. STRONG THUNDERSTORM WINDS AND LOCALLY
HEAVY RAINS ARE POSSIBLE TUESDAY AFTERNOON AND EVENING.

THE CHANCE FOR SHOWERS WILL DECREASE ON WEDNESDAY...WITH NO
WIDESPREAD HAZARDOUS WEATHER EXPECTED THURSDAY THROUGH SUNDAY.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 9, 1:39 AM MSTFlash Flood WarningPSRGila, Maricopa21 min

Nearby

Flash Flood Warnings in Arizona, 2003Every 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.