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 Las Vegas, NV wrote its last area forecast discussion before the first event at Sep 9, 9:35 AM PST, 3 hours 10 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 1035 AM PDT THU SEP 9 2004 .SYNOPSIS...MONSOONAL MOISTURE INCREASING OVER THE REGION WILL BRING MORE WIDESPREAD THUNDERSTORM CHANCES THIS AFTERNOON AND EVENING. THUNDERSTORMS OVER SOUTHERN MOHAVE...SOUTHERN CLARK...AND EASTERN SAN BERNARDINO COUNTIES WILL HAVE THE POTENTIAL TO PRODUCE HEAVY RAINFALL AND FLASH FLOODING THIS AFTERNOON AND EVENING. THE MOISTURE WILL REMAIN OVER THE REGION THROUGH THE END OF THE WEEK BEFORE A TROUGH BEGINS TO MOVE IT EASTWARD SUNDAY. && .UPDATE...MOISTURE CONTINUES TO INCREASE ACROSS THE SOUTHERN REGIONS OF THE CWA. MORNING MODELS SUPPORT PREVIOUS FORECASTER THOUGHTS ON MORE WIDESPREAD HEAVY RAIN POTENTIAL ALONG THE SOUTHERN AND EASTERN REGIONS OF SAN BERNARDINO COUNTY...SOUTHERN CLARK AND MOHAVE COUNTIES. THUS...WILL CONTINUE THE FLOOD WATCH FOR FLASH FLOODING IN THESE AREAS. IN THE LAS VEGAS VALLEY...TSTORMS SHOULD BE OF THE MORE SCATTERED VARIETY BUT WITH THE MCCARRAN PW SENSOR CURRENTLY SHOWING 1.2 INCH PW LEVELS...EXPECT THAT ANY STORMS THAT DO FORM OVER THE VALLEY WILL HAVE THE POTENTIAL FOR HEAVY RAIN. MOISTURE PARAMETERS ARE FORECAST TO INCREASE THROUGH THE DAY AND THE NEARLY CLEAR CONDITIONS WILL ALLOW QUICK TEMP RISE AND DESTABILIZATION OF THE ATMOSPHERE. EARLIER...THUNDERSTORMS FORMED OVER RIVERSIDE COUNTY IN CALIFORNIA AND MODEL MEAN WIND PROGS WOULD BRING THIS THUNDERSTORM ACTIVITY INTO THE SOUTHERN SAN BERNARDINO COUNTY OVER THE NEXT COUPLE OF HOURS AND THEN MOVE THEM TOWARD THE NORTHEAST. ONE GOOD THING...THE STORMS SHOULD MOVE AT A FAIRLY GOOD PACE AS 850-300MB WINDS OF 15KTS ARE FORECAST. SHOULD BEGIN TO SEE CELLS FORM OVER THE HIGHER TERRAIN OVER MUCH OF THE SOUTHERN CWA BY NOON OR EARLY AFTERNOON AND OVER THE DESERTS AND LOWLANDS DURING THE AFTERNOON. THIS IS COVERED IN THE CURRENT FORECAST...SO NO NEED TO UPDATE. .PREV DISCUSSION...315 AM PDT THU SEP 9...MODEL...SATELLITE...AND SURFACE DATA ALL SUPPORT A LARGE INCREASE IN MOISTURE THIS AFTERNOON OVER THE SOUTHERN 1/3 OF THE FORECAST AREA. ETA/GFS RUNS ALSO SHOWING A VERY LARGE AMOUNT OF INSTABILITY OVER THESE SAME AREAS WITH LI FORECASTS AS HIGH AS -6. ONLY REMAINING QUESTION WOULD BE A KICKER TO BETTER ORGANIZE CONVECTION. ETA/GFS HAVE BEEN ADVERTISING A JET STREAK COMING THROUGH THE SOUTHERN CWA THIS AFTERNOON FOR SEVERAL RUNS NOW...AND ALTHOUGH IT IS HARD TO FIND IT ON WATER VAPOR...THERE IS SOME INCREASE CLOUD COVER THIS MORNING OVER CALIFORNIA THAT COULD BE ASSOCIATED WITH THIS FEATURE. THEY ALSO PUT THE THETA-E RIDGE AXIS RIGHT ALONG THE COLORADO RIVER VALLEY AND BRING A NICE CONVERGENCE/DIVERGENCE COUPLET ACROSS THE SOUTHERN CWA THIS AFTERNOON. GIVEN ALL THIS AND HEAVY DOPPLER ESTIMATES YESTERDAY...THERE WERE NO RAINGAGES UNDERNEATH TO VERIFY MOST OF THIS...WILL ISSUE A FLOOD WATCH FOR SOUTHERN MOHAVE...EXTREME SOUTHERN CLARK...AND EASTERN AND SOUTHERN SAN BERNARDINO COUNTIES TODAY. CONVECTION SHOULD BE MORE WIDESPREAD AND SLIGHTLY BETTER ORGANIZED TODAY WITH A SMALL AMOUNT OF SHEAR EXPECTED THIS AFTERNOON. THEY WILL HOWEVER MOVE SLIGHTLY FASTER THAN YESTERDAY. INCREASED POPS FOR FORECAST PACKAGE AS A RESULT OF ALL THE NEW DATA...MOS THUNDERSTORM POTENTIAL SUPPORTS FAIRLY HIGH POPS OVER SOUTHERN 1/3 OF CWA THIS AFTERNOON. MOISTURE SHOULD REMAIN THROUGH SATURDAY AS LATEST MODEL RUNS SUGGEST THE TROUGH EXPECTED FOR THE WEEKEND WILL COME THROUGH SLOWER AND WEAKER THAN PREVIOUSLY EXPECTED. BIGGEST IMPACT IS WEAKER WINDS AND BETTER THUNDERSTORM COVERAGE ON SATURDAY. && .LONG TERM...MODELS IN PRETTY GOOD AGREEMENT SUNDAY THROUGH WEDNESDAY. BROAD LOW AMPLITUDE TROUGH OVER THE PACIFIC NORTHWEST SUNDAY WITH A WEAK SHORTWAVE TROUGH AND NEARLY WESTERLY FLOW OVER THE SOUTHERN GREAT BASIN AND MOJAVE DESERT. MONSOON MOISTURE PRETTY MUCH GETS SCOURED OUT TO THE EAST WITH MAYBE A LITTLE MID LEVEL MOISTURE OVER NORTHEAST MOHAVE COUNTY. WENT WITH A DRY FORECAST AND TEMPERATURES PRETTY CLOSE TO SATURDAY. DOES NOT LOOK BREEZY FOR SUNDAY LIKE IT DID WITH PREVIOUS MODEL RUNS WITH THE MAIN TROUGH BEING FARTHER NORTH AND LESS AMPLIFIED. BROAD TROUGH REMAINS OVER THE FAR WESTERN U.S. THROUGH WEDNESDAY BUT DEEPENS WITH TIME. ASSOCIATED MOISTURE LOOKS TO REMAIN NORTH OF THE FORECAST AREA BUT EXPECT BREEZY CONDITIONS WITH A COOLING TREND. && .AVIATION...FAIRLY CONFIDENT THAT THUNDERSTORMS WILL AFFECT THE TERMINAL AREA THIS AFTERNOON. ONLY QUESTION IS WHEN AND WILL NOT BE ABLE TO ANSWER THAT UNTIL THEY FORM. AS OF THE TIME OF WRITING THIS THINK THUNDERSTORMS COULD FORM IN THE LAS VEGAS VALLEY BY 22Z. MAIN THREAT FROM THESE STORMS WILL BE VERY HEAVY RAIN FALL IN ADDITION TO THE STANDARD HAZARDS LIKE TURBULENCE AND LLWS. && .VEF WATCHES/WARNINGS/ADVISORIES... .NV...FLOOD WATCH FOR FLASH FLOODING UNTIL 10PM FOR NV ZONES 21 AND 22. .AZ...FLOOD WATCH FOR FLASH FLOODING UNTIL 10PM FOR AZ ZONES 02...03 AND 36. .CA...FLOOD WATCH FOR FLASH FLOODING TODAY 10AM UNTIL 10PM FOR CA ZONES 28 AND 29. && SALMEN/JACQUES
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
143 PM PDT THU SEP 09 2004
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION...ST.. ...SOURCE....
..REMARKS..
0127 PM TSTM WND GST NWS LAS VEGAS 36.05N 115.19W
09/09/2004 57 MPH CLARK NV NWS EMPLOYEE
AT WFO LAS VEGAS
&&
JACQUESThe national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
Flash flooding caused several roads to be closed near the town of Nipton. Rocks and debris covered the road in several locations.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2004Every state in 2004This day in weather historyWarnings in California, 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: 5422347.