Monsoon moisture fueled another outbreak of thunderstorms over the Mojave Desert. Some storms produced flash flooding and/or severe weather.
Every event with a place to put it. 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 episode as NWS VEF wrote it up.
Monsoon moisture fueled another outbreak of thunderstorms over the Mojave Desert. Some storms produced flash flooding and/or severe weather.
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 3, 1:39 PM PST, 4 hours 15 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 239 PM PDT MON SEP 3 2012 .SYNOPSIS...MOISTURE FROM NORTHWEST MEXICO AND THE GULF OF CALIFORNIA IS EXPECTED TO SPREAD BACK INTO THE REGION THROUGH THE MIDDLE OF THE WEEK. THIS WILL RESULT IN INCREASING CHANCES OF THUNDERSTORMS OVER SOUTHEAST CALIFORNIA...SOUTHERN NEVADA AND NORTHWEST ARIZONA ON TUESDAY AND ESPECIALLY ON WEDNESDAY. ISOLATED TO SCATTERED THUNDERSTORMS WILL THEN CONTINUE THROUGH THE REST OF THE WEEK. && .SHORT TERM...TONIGHT THROUGH WEDNESDAY...ANOTHER FAIRLY QUIET DAY AROUND THE CWA. HOWEVER A BAND OF CLOUDINESS WHICH MOVED OVER SAN BERNARDINO AND EXTREME SOUTHERN NEVADA LAST NIGHT...HAS MANAGED TO PRODUCE VERY SHALLOW CONVECTION SO FAR THIS AFTERNOON...RESULTING IN MAINLY VIRGA...ESPECIALLY OVER SOUTHERN NEVADA. MAIN INSTABILITY FOR THE REMAINDER OF THE AFTERNOON/EVENING CONTINUES TO BE OVER MOHAVE COUNTY AND WILL LEAVE IN MENTION OF ISOLATED THUNDERSTORMS FOR THIS AREA FOR THE EVENING. SYNOPTIC PATTERN THROUGH THE SHORT TERM REMAINS FAIRLY UNCHANGED WITH A WEAK TROUGH OFF THE WEST COAST AND A RIDGE NUDGING FURTHER WEST THROUGH THE PERIOD. THE RIDGE WILL CREATE INCREASED SOUTH TO SOUTHEAST FLOW INTO MUCH OF THE CWA FOR TUESDAY AND WEDNESDAY WHICH WILL ALLOW INCREASED MOISTURE TO MOVE INTO THE AREA. CURRENT PRECIPITABLE WATER VALUES HAVE BEEN INCREASING SLIGHTLY TODAY WITH SURFACE DEWPOINTS INCREASING ALONG THE COLORADO RIVER VALLEY... ESPECIALLY SOUTH OF OUR CWA WITH YUMA/BLYTHE BOTH HAVING SURFACE DEWPOINTS IN THE 70S. THE GFS IS HINTING AT A WEAK WAVE POSSIBLY MOVING NORTH ALONG BAJA CALIFORNIA THROUGH THE PERIOD WITH THE WAVE PUSHING INTO SOUTHERN CALIFORNIA BY 18Z WEDNESDAY. DECREASING STABILITY/INCREASING POTENTIAL TEMPERATURES/INCREASING PW VALUES ALL POINT TO AN INCREASING CHANCE OF THUNDERSTORMS OVER THE SOUTHEAST PORTION OF THE CWA...ESPECIALLY WEDNESDAY. HAVE SPREAD SLIGHT CHANCE POPS FURTHER WEST WITH THIS PACKAGE FOR WEDNESDAY AND MAY NEED TO INCREASE FURTHER IF THE CURRENT TRENDS CONTINUE. AT THE SAME TIME...A WEAK MOISTURE PUSH CONTINUES TO BE INDICATED INTO THE SOUTHERN SIERRA AND WITH OROGRAPHICS AND WEAK DYNAMICS DUE TO THE OFFSHORE TROUGH...WILL KEEP MENTION OF A SLIGHT CHANCE OF THUNDERSTORMS FOR THIS AREA TOO FOR WEDNESDAY AFTERNOON. TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL THROUGH THE PERIOD. .LONG TERM...MOISTURE IS FORECAST TO BE ENTRENCHED ACROSS THE AREA THURSDAY THROUGH THE WEEKEND AND INTO MONDAY WITH ONLY MINOR AIRMASS FLUCTUATION. FOR INSTANCE...THE GFS HAS ONE INCH PW PUSHING FAR ENOUGH NORTH THAT 3/4THS OF THE FORECAST AREA IS AT OR ABOVE AN INCH MOST OF THE PERIOD. HOWEVER...WITH THE EXCEPTION OF THE SIERRA... THE WESTERN 1/3 OF THE CWA REMAINS FAIRLY STABLE FOR ANYTHING OTHER THAN SOME AFTERNOON CUMULUS BUILDUPS. BASICALLY EXPECT LIMITED SHOWER AND THUNDERSTORM COVERAGE TO A SLIGHT CHANCE ACROSS THE EASTERN HALF OF THE AREA THROUGHOUT THE EXTENDED WITH THE EXCEPTION OF THE MORE SCATTERED VARIETY ON THURSDAY IN THE SAME AREAS. THIS MORNINGS MODELS AGREE THAT A SHARP SHORTWAVE TROUGH ENTERS THE PACIFIC NORTHWEST MONDAY WHICH...BASED ON ITS CURRENT FORECASTED OPEN WAVE PROGRESSIVE NATURE...COULD HELP FLUSH MOISTURE FROM THE AREA BEYOND MONDAY. TEMPERATURES NEAR OR SLIGHTLY ABOVE NORMAL ARE EXPECTED WITH POTENTIALLY SOME MINOR COOLING WITH THE TROUGH. && .AVIATION...FOR MCCARRAN...WINDS SHOULD FAVOR DIURNAL TRENDS INTO THE EVENING WITH GUSTS TO AROUND 15 KTS AT TIMES. THUNDERSTORM ACTIVITY SHOULD BE LIMITED TODAY AND IMPACTS LIMITED TO THE PEACH SPRINGS AND MORMON MESA CORRIDORS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...CLEAR SKIES TO CONTINUE OVER THE NORTHWEST CWA WITH FEW-SCT CLOUDS GENERALLY AOA 11K FEET ELSEWHERE. WINDS WILL FAVOR DIURNAL TRENDS THROUGH TUESDAY WITH GUSTS UP TO 20KTS AT TIMES. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && JENSEN/SALMEN HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 404 AM PDT MON SEP 3 2012 AZZ001>003-036-CAZ519>527-NVZ014>022-040700- NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS- LAKE MEAD NATIONAL RECREATION AREA-EASTERN SIERRA SLOPES- OWENS VALLEY-WHITE MOUNTAINS OF INYO COUNTY- DEATH VALLEY NATIONAL PARK-WESTERN MOJAVE DESERT- EASTERN MOJAVE DESERT-MORONGO BASIN-CADIZ BASIN- SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY- ESMERALDA AND CENTRAL NYE COUNTY-LINCOLN COUNTY- NORTHEAST CLARK COUNTY-WESTERN CLARK AND SOUTHERN NYE COUNTY- SHEEP RANGE-SPRING MOUNTAINS-LAS VEGAS VALLEY- SOUTHERN CLARK COUNTY- 404 AM PDT MON SEP 3 2012 /404 AM MST MON SEP 3 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT MOISTURE INCREASING OVER NORTHWEST ARIZONA TODAY WILL LEAD TO SOME THUNDERSTORMS IN MOHAVE COUNTY DURING THE AFTERNOON AND EARLY EVENING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY MONSOONAL MOISTURE IS EXPECTED TO RETURN TO SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA TUESDAY AND ESPECIALLY WEDNESDAY LEADING TO AN INCREASING CHANCE OF THUNDERSTORMS. ONCE IN PLACE...THE MOISTURE WILL LINGER THE REST OF THE WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. HOWEVER... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. JA
The Las Vegas radar (KESX), 129 km away, was scanning. The volume nearest the first event began at 01:55 UTC.
3 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Highway 95 was closed from Havasu Lake Road to Vidal Junction due to flooding.
Highway 62 was flooded near mile marker 40 with vehicles stuck.
Several large pine trees and power poles were blown down. One house had roof damage, and the Needles Movie Theater had its roof completely blown off.
Water and debris were running across Highway 95 north of I-40.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2012Every state in 2012This day in weather historyWarnings in California, September 2012
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: 401982, 402000, 402003, 402007.