Monsoon moisture fueled another round of thunderstorms over the Mojave Desert. A few storms produced flash flooding and 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 round of thunderstorms over the Mojave Desert. A few storms produced flash flooding and 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 7, 2:10 PM MST, 50 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 210 PM PDT FRI SEP 7 2012 .SYNOPSIS...HIGH PRESSURE DEVELOPING OVER NEVADA WILL LIMIT THUNDERSTORM CHANCES TO MAINLY MOHAVE COUNTY THIS EVENING AND ACROSS NORTHWEST ARIZONA AND SOUTHEAST CALIFORNIA ON SATURDAY. DEEP MOISTURE WILL INCREASE AREA WIDE SUNDAY INTO MONDAY AS A LOW PRESSURE CIRCULATION MOVES FROM NORTHERN BAJA UP ACROSS THE MOJAVE DESERT. THIS WILL RESULT IN AN INCREASING THREAT OF THUNDERSTORMS AND FLASH FLOODING BOTH DAYS. DRIER AIR IS EXPECTED TO GRADUALLY PUSH IN FROM THE WEST BY THE MIDDLE OF NEXT WEEK. && .SHORT TERM...DEEP MOISTURE AND A NEARLY STATIONARY LOW PRESSURE SYSTEM WERE LURKING TO THE SOUTH/SOUTHEAST OF THE FORECAST AREA THIS AFTERNOON. FLOW AROUND HIGH PRESSURE DEVELOPING OVER NEVADA WILL HELP KEEP THE DEEP MOISTURE AND AREA OF LOW PRESSURE OUT OF THE AREA THROUGH SATURDAY. SOME MOISTURE WILL BE AROUND THE PERIPHERY OF THE HIGH LEADING TO A CHANCE OF THUNDERSTORMS MAINLY OVER MOHAVE COUNTY THIS EVENING WITH MOISTURE AND THUNDERSTORMS CHANCES THEN ALSO SPREADING CLOCKWISE AROUND THE HIGH ACROSS SAN BERNARDINO AND INYO COUNTIES SATURDAY AFTERNOON AND EVENING. THE DEEP MOISTURE WILL THEN MOVE UP INTO THE AREA SUNDAY AND MONDAY AS THE AREA OF HIGH PRESSURE SHIFTS TO OUR EAST...ALLOWING THE LOW PRESSURE SYSTEM TO GRADUALLY MOVE NORTH INTO THE MOJAVE DESERT. AS A RESULT...THUNDERSTORMS WILL BECOME MORE WIDESPREAD BOTH SUNDAY AND MONDAY. PRECIPITABLE WATER VALUES INCREASE TO OVER 1.5 INCHES IN THE SOUTHERN PART OF THE FORECAST AREA LEADING TO AN INCREASED CHANCE OF FLASH FLOODING...ESPECIALLY ACROSS MOHAVE AND CLARK COUNTIES...EASTERN PORTIONS OF SAN BERNARDINO COUNTY AND SOUTHERN LINCOLN COUNTY. ALTHOUGH THE MOISTURE AND INSTABILITY BOTH INCREASE SUNDAY...THE NEGATIVE FOR FLASH FLOOD PRODUCING STORMS COULD BE SIGNIFICANT CLOUD COVER MOVING IN SATURDAY NIGHT. THIS WOULD LIMIT SURFACE HEATING AND END UP RESULTING IN JUST A CLOUDY DAY WITH SOME LIGHT RAIN. DUE TO THIS UNCERTAINTY...A FLASH FLOOD WATCH WILL NOT YET BE ISSUED FOR SUNDAY. FOR MONDAY...THERE MAY BE MORE UPPER LEVEL DYNAMICAL SUPPORT FOR STORMS IF THE LOW PRESSURE SYSTEM MAINTAINS AND DOES MOVE UP INTO THE MOJAVE DESERT AS THE MODELS DEPICT. MEANWHILE...DRIER AIR WILL START TO MOVE INTO THE FAR WESTERN PART OF THE FORECAST AREA LATE MONDAY AND MONDAY NIGHT. .LONG TERM...MODELS ARE IN DECENT AGREEMENT THIS MORNING AS A CLOSED LOW OVER THE SOUTHERN PORTIONS OF THE COLORADO RIVER VALLEY GETS KICKED EAST AS A BROAD TROUGH MOVES INTO THE WESTERN STATES. ONE DIFFERENCE BETWEEN THE GFS AND ECMWF IS THAT THE ECMWF IS SHOWING A SECONDARY VORT LOBE MOVING THROUGH SOUTHERN NEVADA TUESDAY AFTERNOON. THERE MAY BE ENOUGH ENERGY ASSOCIATED WITH THIS FEATURE ALONG WITH SOME AVAILABLE MOISTURE TO KEEP MENTION OF THUNDERSTORMS IN THE FORECAST OVER THE EASTERN THIRD OF THE AREA. DRIER AIR WILL BEGIN TO WORK INTO FROM THE WEST WEDNESDAY AND THURSDAY...BUT HIGH PRESSURE OVER NORTHERN BAJA MAY WORK FAR ENOUGH NORTH TO HELP ADD SOME ADDITIONAL MOISTURE AND KEEP AT LEAST A SLIGHT CHANCE OF THUNDERSTORMS OVER MAINLY MOHAVE COUNTY. THE GFS/ECMWF KEEPS THE HIGH STRONG ENOUGH TO DEFLECT ANY UPPER TROUGH WHICH WILL KEEP SOME MOISTURE IN PLACE A LITTLE LONGER...AT LEAST THROUGH THE END OF NEXT WEEK. TEMPERATURES ARE EXPECTED TO BE CLOSE TO NORMAL THROUGH MUCH OF THE WEEK. && .AVIATION...FOR MCCARRAN...WINDS ARE EXPECTED TO REMAIN UNDER 10KTS THROUGH TONIGHT AND GENERALLY BE FROM A EAST TO SOUTHEAST DIRECTION THROUGH 03Z. WINDS WILL THEN TURN MORE SOUTHWEST FOR THE REMAINDER OF TONIGHT. THUNDERSTORMS ARE EXPECTED TO MAINLY BE CONFINED TO MOHAVE AND SOUTHERN LINCOLN COUNTIES AND AFFECT THE PEACH SPRINGS AND MORMON MESA CORRIDORS. STILL POSSIBLE THAT GUSTY OUTFLOW WINDS WILL AFFECT MCCARRAN LATE THIS AFTERNOON AND EVENING. CONDITIONS ON SATURDAY EXPECTED TO BE LIKE TODAY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED TO SCATTERED SHRA/TSRA ARE EXPECTED FOR THE REMAINDER OF THIS AFTERNOON OVER MOHAVE COUNTY WITH GENERALLY LESSER CHANCES ELSEWHERE. STORMS SHOULD GRADUALLY DISSIPATE THIS EVENING. MAINLY SCT CLOUDS AOA 15K FEET WITH BASES AS LOW AS 5-8K FEET IN AND NEAR ANY SHRA/TSRA. WINDS UNDER 10KTS AREAWIDE...EXCEPT NEAR STORMS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && HARRISON/GORELOW HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 447 AM PDT FRI SEP 7 2012 AZZ001>003-036-CAZ524>527-NVZ015-016-018>022-080700- NORTHWEST PLATEAU-LOWER COLORADO RIVER VALLEY-NORTHWEST DESERTS- LAKE MEAD NATIONAL RECREATION AREA-EASTERN MOJAVE DESERT- MORONGO BASIN-CADIZ BASIN-SAN BERNARDINO COUNTY- UPPER COLORADO RIVER VALLEY-LINCOLN COUNTY-NORTHEAST CLARK COUNTY- SHEEP RANGE-SPRING MOUNTAINS-LAS VEGAS VALLEY- SOUTHERN CLARK COUNTY- 447 AM PDT FRI SEP 7 2012 /447 AM MST FRI SEP 7 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT ISOLATED THUNDERSTORMS CAN BE EXPECTED THIS AFTERNOON AND EVENING. THUNDERSTORMS MAY PRODUCE OVER ONE INCH OF RAIN IN LESS THAN AN HOUR PRIMARILY OVER MOHAVE COUNTY ARIZONA. STRONG GUSTY WINDS MAY ALSO OCCUR WITH ANY STRONGER STORMS THAT DEVELOP. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY DEEP MOISTURE IS EXPECTED TO MOVE UP FROM NORTHERN MEXICO AND SOUTHERN ARIZONA LATE SATURDAY THROUGH MONDAY. THUNDERSTORM COVERAGE MAY BE MORE EXTENSIVE SUNDAY AND MONDAY AS LOW PRESSURE CIRCULATION MOVES FROM NORTHERN BAJA ACROSS THE MOJAVE DESERT REGION. THE PRIMARY THREAT WILL BE THE POTENTIAL FOR HEAVY RAIN AND FLASH FLOODING WITH SOME STORMS. A GRADUAL DRYING TREND IS EXPECTED TUESDAY THROUGH WEDNESDAY WITH DECREASING CHANCES OF THUNDERSTORMS EACH DAY FROM WEST TO EAST. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS A POSSIBILITY SUNDAY AND MONDAY. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. CAZ519>523-NVZ014-017-080700- EASTERN SIERRA SLOPES-OWENS VALLEY-WHITE MOUNTAINS OF INYO COUNTY- DEATH VALLEY NATIONAL PARK-WESTERN MOJAVE DESERT- ESMERALDA AND CENTRAL NYE COUNTY- WESTERN CLARK AND SOUTHERN NYE COUNTY- 447 AM PDT FRI SEP 7 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED TO REDEVELOP OVER INYO AND WESTERN SAN BERNARDINO COUNTIES IN CALIFORNIA AND MUCH OF SOUTHWEST NEVADA SUNDAY. LOCALIZED FLASH FLOODING WILL BE THE PRIMARY THREAT...ESPECIALLY OVER WESTERN SAN BERNARDINO...SOUTHERN INYO AND SOUTHERN NYE COUNTIES. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS A POSSIBILITY SUNDAY FOR SAN BERNARDINO COUNTY. SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
The Las Vegas radar (KESX), 94 km away, was scanning. The volume nearest the first event began at 22:00 UTC.
2 flash flood, 1 thunderstorm wind. Local standard time, as filed.
A 10 foot tall tree was uprooted, and three smaller trees were damaged. Half of a business sign was damaged.
Several roads in the northeast part of Golden Valley, AZ were impassable with at least two feet of water flowing over them.
Diamond Creek Road was flooded north of Peach Springs.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2012Every state in 2012This day in weather historyWarnings in Arizona, 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: 402023, 402024, 402026.