1 flash flood, as filed by the National Weather Service.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The local office's own words before the first event, 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 the first event at Sep 18, 10:00 PM MST, 4 hours earlier.
AZZ020>028-CAZ030>033-191045- AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX AZ 1000 PM MST SAT SEP 18 2004 SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA FORECAST DISCUSSION .SYNOPSIS... AN EARLY SEASON COLD LOW PRESSURE SYSTEM WILL SLOWLY DEVELOP OVER THE WESTERN STATES...AND PULL A SIGNIFICANT AMOUNT OF SUBTROPICAL MOISTURE FROM TROPICAL STORM JAVIER INTO MAINLY ARIZONA TONIGHT AND SUNDAY. THIS WILL LEAD TO A GOOD CHANCE FOR SHOWERS AND THUNDER STORMS WITH THE POTENTIAL FOR LOCALLY HEAVY RAIN OVER SOUTH CENTRAL ARIZONA. A COLD FRONT WILL FINALLY SWEEP THROUGH THE REGION MONDAY FOR A RETURN TO DRY WEATHER TUESDAY THROUGH SATURDAY. && .DISCUSSION... STRONG HIGH AMPLITUDE UPPER TROF CONTINUES TO DIG ALONG THE WEST COAST...AND THE SLY FLOW AHEAD OF THE TROF IS PULLING SUBSTANTIAL TROPICAL MOISTURE INTO THE STATE FROM OLD HURRICANE JAVIER...NOW A DEPRESSION JUST ALONG THE SRN TIP OF BAJA CA. GOES PWAT IMAGERY CLEARLY SHOWS THE MASSIVE INFLUX OF MOISTURE INTO THE STATE FROM THE SOUTH...WITH A TONGUE OF 1.5 INCH PLUS AMOUNTS NOSING INTO SRN AZ. 00Z PHX/TUS RAOBS BOTH REPORTED AT OR OVER 1.75 INCHES PWAT. ALSO...SURFACE DEWPOINTS OVER MOST OF THE CWA ARE NOW RUNNING IN THE MID 60S TO MID 70S. EARLIER A SHORT WAVE MOVING THRU THE FLOW ACTED ON THIS MOISTURE TO PRODUCE SCT TO NUMEROUS SHOWERS AND STORMS OVER OUR ERN ZONES...AND SOME GAGES IN ZONE 28 REPORTED FROM 1 TO 2 INCHES OF RAINFALL WITH THOSE STORMS. THE IMPULSE HAS SHIFTED TO OUR NORTH AND AS OF 9 PM MOST OF THE CWA WAS IN A LULL IN THE WEATHER WITH SOME BREAKS IN THE CLOUDS SEEN OVER SWRN AZ. MODELS ARE PRETTY CONSISTENT WITH THEIR FORECASTS...AND ARE STILL CALLING FOR SUBSTANTIAL MOISTURE TO KEEP MOVING INTO AZ AHEAD OF THE WEST COAST TROF...WITH THE MAIN FOCUS FOR THE HEAVY RAIN AND DEEP MOISTURE TO BE EAST OF THE COLORADO RIVER...MAINLY IN THE AREA FROM MARICOPA COUNTY EASTWARD. BOTH THE ETA AND GFS PLACE SCNTRL AZ UNDER THE RIGHT REAR QUAD OF A STRONG UPPER JET...AND THIS JET DYNAMICS MAXIMIZES BY ABOUT 12Z SUNDAY...THEN DIMINISHES DURING THE DAY AS THE UPPER JET CORE LIFTS TO THE NORTHEAST. BOTH MODELS INCREASE THE LOW/MID LEVEL OMEGA VALUES SUBSTANTIALLY FROM MIDNIGHT TONIGHT THRU 12Z SUNDAY...WITH DECENT OMEGA/UVV CONTINUING WELL INTO THE DAY SUNDAY. WITH PWAT VALUES WELL OVER 1.5 INCHES OVER SCNTRL AZ...AND LIFT INCREASING...EXPECT A REDEVELOPMENT OF CLOUDS AND SHOWERS OVER OUR ERN CWA FROM MIDNIGHT ONWARD TONIGHT. THUS WILL LEAVE THE POPS AND WEATHER ALONE FOR TONIGHT DESPITE THE CURRENT RESPITE FROM THE PRECIP. AGAIN...THE WRN ZONES APPEAR TO BE PRETTY MUCH OUT OF THE WOODS AND ONLY ISOLATED THUNDERSTORMS WERE SEEN THERE EARLIER TODAY WITH THE STRONGEST CELLS NOTED OVER CENTRAL IMPERIAL COUNTY. AS OF 9 PM NO LIGHTNING/STORMS WERE SEEN OVER THE WRN ZONES. BY 18Z...THE GFS FORECASTS 6 PLUS LIFTED INDICES AND 850MB DEWPOINTS BELOW ZERO FROM THE CO RIVER WESTWARD. THUS THREAT FOR STORMS TOMORROW OUT WEST IS LIMITED AS THE DRY STABLE AIR STARTS BEING ADVECTED INTO OUR AREA. DUE TO THE HIGH AMPLITUDE NATURE OF THE TROF...IT IS SLOW TO PROGRESS EAST...UNTIL ABOUT MONDAY NIGHT. THUS MOISTURE WILL LINGER FOR AWHILE OVER THE ERN CWA...WITH VERY HIGH 850MB DEWPOINTS FROM PHX EAST WELL INTO THE DAY MONDAY. CURRENT FORECASTS LOOK TO BE PRETTY GOOD AND NO MAJOR CHANGES WILL BE MADE THIS EVENING. IT STILL LOOKS LIKE THE MAIN WINDOW FOR THE HEAVIEST RAINFALL FOR THE PHX CWA WILL BE LATER TONIGHT THRU SUNDAY EVE. FROM PHX EAST...SOME AREAS COULD EASILY PICK UP FROM 1 TO 2 INCHES...OR MORE...BY MIDNIGHT SUNDAY. && .PSR WATCHES/WARNINGS/ADVISORIES... AZ...FLASH FLOOD WATCH SOUTH CENTRAL ZONES 22...23...24...27... 28 TONIGHT AND SUNDAY. CA...NONE. && 11
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 1050 AM MST SAT SEP 18 2004 AZZ020-021-025-026-CAZ031>033-190400- IMPERIAL COUNTY-LOWER COLORADO RIVER VALLEY AZ- LOWER COLORADO RIVER VALLEY CA-RIVERSIDE COUNTY/EASTERN DESERTS- SOUTHWEST DESERTS-WEST CENTRAL DESERTS- YUMA/MARTINEZ LAKE AND VICINITY- 1050 AM MST SAT SEP 18 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR FAR EASTERN RIVERSIDE AND FAR EASTERN IMPERIAL COUNTIES IN CALIFORNIA...AND YUMA AND LA PAZ COUNTIES IN ARIZONA. .DAY ONE...TODAY THE COMBINATION OF A COLD FRONT MOVING THROUGH THE WESTERN STATES...AND THE ENTRAINMENT OF SUBTROPICAL MOISTURE FROM HURRICANE JAVIER...WILL RESULT IN AN INCREASING CHANCE FOR LARGE FAST MOVING THUNDERSTORMS WITH HEAVY RAIN AND STRONG WINDS. THE THUNDERSTORM THREAT WILL CONTINUE INTO THE EVENING HOURS. THE MOST VULNERABLE AREAS ARE EASTERN RIVERSIDE AND EASTERN IMPERIAL COUNTIES TOWARD THE COLORADO RIVER...AND ALL OF YUMA AND LA PAZ COUNTIES IN ARIZONA. HURRICANE MOISTURE MOVING AHEAD OF A STRONG COLD FRONT IS AN UNUSUAL WEATHER EVENT...AND THOSE CONCERNED SHOULD CONTINUE TO MONITOR WEATHER FORECASTS IN CASE WEATHER WATCHES...WARNINGS...OR ADVISORIES ARE NEEDED TODAY. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA OUTLETS FOR UPDATES. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. AZZ022>024-027-028-190400- GREATER PHOENIX AREA-NORTHWEST AND NORTH CENTRAL PINAL COUNTY- NORTHWEST MARICOPA COUNTY-SOUTHERN GILA/TONTO NF FOOTHILLS- SOUTHWEST MARICOPA COUNTY- 1050 AM MST SAT SEP 18 2004 THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL ARIZONA. .DAY ONE...TODAY THE COMBINATION OF A COLD FRONT MOVING THROUGH THE WESTERN STATES...AND THE ENTRAINMENT OF SUBTROPICAL MOISTURE FROM HURRICANE JAVIER...WILL RESULT IN AN INCREASING CHANCE FOR SHOWERS AND STRONG THUNDERSTORMS TODAY. THERE IS A THREAT FOR HEAVY RAIN AND STRONG THUNDERSTORM WINDS WHICH WILL LAST INTO THE EVENING HOURS. THE ENTRAINMENT OF TROPICAL MOISTURE AHEAD OF A STRONG COLD FRONT IS AN UNUSUAL WEATHER EVENT...AND THOSE CONCERNED SHOULD CONTINUE TO MONITOR WEATHER FORECASTS IN CASE WEATHER WATCHES... WARNINGS...OR ADVISORIES ARE NEEDED. HEAVY RAINS MAY CAUSE MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. WASHES MAY BEGIN FLOWING. STAY TUNED TO NOAA WEATHER RADIO OR YOUR LOCAL MEDIA OUTLETS FOR UPDATES. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY SHOWERS AND THUNDERSTORMS WITH HEAVY RAIN WILL CONTINUE ON SUNDAY AS THE COLD FRONT APPROACHES ARIZONA. HEAVY RAINS MAY CAUSE MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. WASHES MAY BEGIN FLOWING
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX AZ
1008 PM MST SAT SEP 18 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0408 PM DUST STORM MARICOPA 33.06N 112.05W
09/18/2004 PINAL AZ LAW ENFORCEMENT
MULTI VEHICLE PILE UP AT HIGHWAY 347 AND MARICOPA
0440 PM DUST STORM PHOENIX 33.54N 112.07W
09/18/2004 MARICOPA AZ TRAINED SPOTTER
VISIBILITY LESS THAN ONE-QUARTER MILE AT INDIAN SCHOOL
AND DYSART ROADS
0511 PM DUST STORM 5 NE BUCKEYE 33.43N 112.54W
09/18/2004 MARICOPA AZ TRAINED SPOTTER
VISIBILITY 400 FEET
0516 PM TSTM WND GST 5 NE BUCKEYE 33.43N 112.54W
09/18/2004 65 MPH MARICOPA AZ TRAINED SPOTTER
0530 PM DUST STORM 4 SW WITTMANN 33.74N 112.58W
09/18/2004 MARICOPA AZ TRAINED SPOTTER
VISIBILITY LESS THAN 100 YARDS AT 249TH AVENUE AND PATTON
ROAD
0601 PM DUST STORM WICKENBURG 33.97N 112.75W
09/18/2004 MARICOPA AZ TRAINED SPOTTER
VISIBILITY LESS THAN ONE-EIGTH OF A MILE
&&
RARThe Yuma radar (KYUX), 151 km away, was scanning. The volume nearest the first event began at 09:00 UTC.
1 flash flood. Local standard time, as filed.
Very heavy rain resulted in flooding of homes and highways in the Parker area. One gauge indicated 1.15 inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2004Every state in 2004This day in weather historyWarnings in Arizona, September 2004
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5422846.