2 hail, 1 thunderstorm wind, 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 4, 2:25 PM MST, 3 hours 15 minutes earlier.
AZZ020>028-CAZ030>033-050545- SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PHOENIX ARIZONA 225 PM MST THU SEP 4 2003 .SYNOPSIS... AN INCREASE IN LOW LEVEL MOISTURE FROM THE GULF OF CALIFORNIA WILL BRING AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS OVER FAR SOUTHEAST CALIFORNIA...AS WELL AS SOUTHWEST AND SOUTH CENTRAL ARIZONA...THROUGH FRIDAY EVENING. HIGH PRESSURE ALOFT WILL MOVE FROM EASTERN ARIZONA TO NEAR SAN DIEGO BY SATURDAY MORNING...WITH SOME DRYING AND A LITTLE WARMER DAYTIME HIGHS OVER THE WEEKEND. THE CHANCE FOR STORMS ON SATURDAY WILL EXIST MAINLY OVER THE HIGHER TERRAIN OF SOUTH CENTRAL ARIZONA. STRONG UPPER LEVEL LOW PRESSURE WILL MOVE INTO THE PACIFIC NORTHWEST LATE IN THE WEEKEND...PERSIST THROUGH THE MIDDLE OF NEXT WEEK...AND KEEP HIGH PRESSURE ALOFT TO OUR SOUTH. THIS WILL RESULT IN DRY WEST TO NORTHWEST FLOW...AND LEAD TO MOSTLY CLEAR SKIES AND NEAR NORMAL TEMPERATURES NEXT WEEK. .DISCUSSION... 18Z PHOENIX SOUNDING QUITE UNSTABLE...WITH MLCAPE (SFC-850MB LAYER) OF 1200 J/KG. NEGATIVE AREA BELOW LFC...SO DECENT OUTFLOW FROM STORMS OVER HIGHER TERRAIN WILL BE REQUIRED TO RELEASE INSTABILITY OVER LOWER DESERT. SFC-500 MB WINDS VERY LIGHT...1O KT OR LESS... GENERALLY FROM THE SOUTHEAST...AND 0-6KM SHEAR NEARLY NON-EXISTENT ...SO EXPECT SHORT LIVED...DISORGANIZED...AND VERY SLOW MOVING STORMS THIS AFTN AND EVENING. DECENT WEST WIND AT AND ABOVE 350 MB LVL ...WITH 40 KT OBSERVED NEAR 200 MB...BUT MOST DIFFLUENT FLOW NOTED MAINLY NORTH OF OUR CWA IN SOUTHEAST CALIFORNIA. SO...WILL HOLD ONTO SLGT CHC FOR STORMS THIS EVENING OVER MOST OF CWA. GIVEN OBSERVED THUNDERSTORM DEVELOPMENT OVER YAVAPAI AND NORTHERN GILA COUNTIES ...AND EXPECTATION OF HALFWAY DECENT OUTFLOW TO MOVE SOUTH AND WEST TOWARD LOWER DESERT...WOULD EXPECT THE BEST CHANCE FOR STORMS OVER SOUTH CENTRAL AZ LOWER DESERT THIS EVENING. GIVEN THE LARGE CAPE ...ANY STORMS THAT DO GET TRIGGERED COULD BE SEVERE...WITH LOCALLY HEAVY RAIN...HIGH WINDS AND HAIL POSSIBLE. WILL HOLD ONTO A CHANCE FOR AFTN/EVENING STORMS FRIDAY ALSO...AS HIGH MOVES TO OUR WEST AND DEEP LAYERED LIGHT NORTH-NORTHWEST FLOW DEVELOPS. NOT SURE HOW UNSTABLE IT WILL BE FRIDAY AFTN/EVENING...AS EVOLUTION OF STORMS THIS EVENING IS NOT CLEAR CUT...BUT STILL A LOT OF CONVECTION TO OUR SOUTH THIS AFTN...SO WOULD NOT BE SURPRISED TO SEE LOW LEVEL MOISTURE REMAIN PLENTIFUL OVER OUR CWA THRU AT LEAST FRIDAY EVENING...ALONG WITH AT LEAST LOW-END CAPE. DRYING STILL EXPECTED TO COMMENCE IN LOW LEVELS BY SATURDAY...FROM WEST TO EAST ACROSS THE CWA...AND WE WILL HAVE TO WATCH FOR THE POSSIBILITY OF ISOLATED SEVERE STORMS SAT AFTN/EVENING...ESPECIALLY OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. FURTHER DRYING IS EXPECTED NEXT WEEK AS DEEP WEST TO NORTHWEST FLOW DEVELOPS. UPPER HIGH PROGGED TO REMAIN FAIRLY STRONG AND BE CENTERED NEAR OR JUST SOUTH OF YUMA THIS WEEKEND...SO WENT WITH A BIT WARMER DAYTIME HIGHS COMPARED TO WHAT WILL OCCUR FRIDAY. EXPECT A TREND TOWARD NEAR NORMAL TEMPS TO BEGIN EARLY NEXT WEEK AS TROUGH DIGS INTO WESTERN UNITED STATES...WITH 500 MB HEIGHTS LOWERING TO NEAR NORMAL LEVELS BY TUESDAY. LATEST GFS INDICATES SOMEWHAT PROGRESSIVE UPPER FLOW EXPECTED TOWARD THE END OF NEXT WEEK...WITH A CHANCE FOR A BIT OF WARMING BY THURSDAY AS HEIGHTS/THICKNESSES EDGE UPWARD. DG .PSR...NONE.
AZZ020>028-CAZ030>033-050100- HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE PHOENIX AZ 100 PM MST THU SEP 4 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. HOWEVER...ISOLATED STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP MAINLY OVER THE HIGHER TERRAIN THIS AFTERNOON...WITH A FEW STRONG STORMS POSSIBLE OVER THE LOWER DESERT. STORMS WILL MOVE VERY SLOWLY...SO LOCALLY HEAVY RAIN WILL BE POSSIBLE. IN ADDITION...STRONG GUSTY WINDS...HAIL...AND INTENSE CLOUD TO GROUND LIGHTNING WILL ACCOMPANY THE STRONGEST STORMS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. HOWEVER...ISOLATED THUNDERSTORMS ARE EXPECTED TO AFFECT MAINLY SOUTH CENTRAL ARIZONA FRIDAY AFTERNOON AND EVENING...WITH A CHANCE FOR STORMS MAINLY OVER THE HIGHER TERRAIN OF SOUTH CENTRAL ARIZONA SATURDAY AFTERNOON AND EVENING.
The Phoenix radar (KIWA), 124 km away, was scanning. The volume nearest the first event began at 00:39 UTC.
2 hail, 1 thunderstorm wind, 1 flash flood. Local standard time, as filed.
Several reports of large hail, from dime size to one inch diameter, in and near Wickenburg.
Shingles blown off roof.
Sols Wash grew to about 150 feet wide, and Flying E Wash was running full. Flooding closed Vulture Mine Road due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2003Every state in 2003This day in weather historyWarnings in Arizona, September 2003
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: 5337925, 5337926, 5337927, 5337980.