Lingering monsoon moisture continued to fuel scattered thunderstorms over the Mojave Desert. Isolated severe weather and flash flooding occurred.
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.
Lingering monsoon moisture continued to fuel scattered thunderstorms over the Mojave Desert. Isolated severe weather and flash flooding occurred.
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 Aug 30, 9:17 AM PST, 2 hours 23 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 1017 AM PDT THU AUG 30 2012 .SYNOPSIS...ISOLATED THUNDERSTORMS ARE EXPECTED OVER MUCH OF THE AREA TODAY WITH TEMPERATURES WARMING TO NEAR NORMAL. MOISTURE INCREASES FRIDAY AND BEGINS INTERACTING WITH STRONGER WINDS ALOFT FOR A MORE FAVORABLE THUNDERSTORM ENVIRONMENT. NOCTURNAL STORM ACTIVITY COULD LINGER THROUGH FRIDAY NIGHT WITH MORE STORMS EXPECTED ACROSS THE CENTRAL AND EASTERN FORECAST AREA ON SATURDAY. TEMPERATURES WILL BE NEAR NORMAL THROUGH THE PERIOD BUT MAY BE COOLER IN AREAS WHERE CLOUD COVER AND SHOWERS DEVELOP AND LINGER. && .UPDATE...SATELLITE AND RADAR TRENDS SUGGEST WEAK CONVECTION ACROSS LINCOLN COUNTY WILL CONTINUE TO MOVE NORTHEAST ACROSS THE COUNTY THROUGH THE MORNING WITH AN AREA OF HIGHER THETA-E. AS SUCH...HAVE UPPED TO SLIGHT CHANCE POPS ACROSS LINCOLN THROUGH THE REMAINDER OF THE MORNING. VERY MINOR TWEAKS WERE MADE TO AFTERNOON HIGHS...OTHERWISE PREVIOUS FORECAST REMAINS ON TRACK THROUGH FRIDAY. 12Z MODEL GUIDANCE INDICATES A ELEVATED CHANCE OF ORGANIZED CONVECTION SATURDAY. WILL BE LOOKING AT THAT WITH THIS AFTERNOONS FORECAST PACKAGE. && .PREV DISCUSSION... 349 AM PDT THU AUG 30 2012 .SYNOPSIS...ISOLATED THUNDERSTORMS ARE EXPECTED OVER MUCH OF THE AREA TODAY WITH TEMPERATURES WARMING TO NEAR NORMAL. MOISTURE INCREASES FRIDAY AND BEGINS INTERACTING WITH STRONGER WINDS ALOFT FOR A MORE FAVORABLE THUNDERSTORM ENVIRONMENT. NOCTURNAL STORM ACTIVITY COULD LINGER THROUGH FRIDAY NIGHT WITH MORE STORMS EXPECTED ACROSS THE CENTRAL AND EASTERN FORECAST AREA ON SATURDAY. TEMPERATURES WILL BE NEAR NORMAL THROUGH THE PERIOD BUT MAY BE COOLER IN AREAS WHERE CLOUD COVER AND SHOWERS DEVELOP AND LINGER. && .SHORT TERM...SATELLITE PRESENTATION AND RADAR RETURNS ALONG WITH LIGHTNING DETECTION DATA SHOW A FEW THUNDERSTORMS CONTINUING IN CENTRAL NYE AND LINCOLN COUNTIES AT THIS HOUR. MAINLY CLEAR SKIES TO SCATTERED CLOUDS WERE FOUND ELSEWHERE WITH ONE WEAK ISOLATED STORM CELL FORMING SOUTH OF THE LAS VEGAS VALLEY. THERE WERE ALSO STORMS NOTED IN COCONINO COUNTY NEAR FLAGSTAFF AND IN SOUTHERN YUMA COUNTY THAT WERE MOVING IN A GENERAL NORTHWEST DIRECTION. FORECASTED MOISTURE AND STABILITY PARAMETERS INDICATE THAT STORMS COULD POP JUST ABOUT ANYWHERE TODAY...INITIALLY TIED TO THE MOUNTAINS AND THEN A FEW ROLLING OFF INTO THE VALLEYS. THE STEERING FLOW TODAY WILL DIRECT STORMS TO THE NORTH/NORTHEAST AT AROUND 15 MPH. LOCAL HI-RES MODEL QPF FORECASTS ALIGN WITH COARSER RESOLUTION MODELS AND ALONG AREAS OF HIGHER FORECASTED THETA E TODAY. THE BEST POTENTIAL FOR STORM DEVELOPMENT INCLUDES THE EASTERN EDGES OF MOHAVE COUNTY...WESTERN AND NORTHEAST SAN BERNARDINO COUNTY...THE CLARK COUNTY MOUNTAINS AND ALONG THE SPINE OF THE SOUTHERN SIERRA. THERE COULD BE A FEW NOCTURNAL STORMS TONIGHT AS TROUGHING OFF THE WEST COAST COMES INTO PLAY. FRIDAY CONTINUES TO LOOK LIKE A VERY ACTIVE DAY OVER MUCH OF THE CWA WITH PW VALUES IN EXCESS OF AN INCH OVER TWO THIRDS OF THE FORECAST AREA INTERACTING WITH WHAT IS NOW FORECASTED TO BE AN 80KT UPPER LEVEL JET CROSSING THE NORTHWEST CWA. FORECAST SOUNDINGS SHOW 1.25 INCHES OF PW AND WEAK SHEAR IN CLARK COUNTY TODAY INCREASING TO 1.5 INCHES OF PW ON FRIDAY WITH INCREASING SHEAR. THIS COULD PROVIDE AN ENVIRONMENT FOR BETTER ORGANIZED AND LONGER LASTING STORM ACTIVITY. WITH ALL MODELS FORECASTING WIDESPREAD PRECIPITATION ON FRIDAY...WILL BE CONSIDERING A FLASH FLOOD WATCH WHICH COULD INCLUDE A RELATIVELY LARGE AMOUNT OF CWA REAL ESTATE. TEMPERATURES OVERALL NEAR NORMAL TODAY AND THEN BELOW NORMAL FRIDAY AND SATURDAY. .LONG TERM...MODELS INDICATE A PACIFIC TROUGH OFF THE WEST COAST WILL SLOWLY MOVE INLAND OVER THE WEEKEND...BUT WILL EVENTUALLY WEAKEN AND LIFT NORTH AS HIGH PRESSURE TO THE SOUTH AND EAST REMAINS STRONG. THIS HIGH WILL HELP KEEP SOME MOISTURE OVER THE AREA INTO AT LEAST EARLY NEXT WEEK WITH THUNDERSTORM CHANCES REMAINING HIGHEST OVER THE FAR EASTERN AREAS OF THE CWA. THE ECMWF IS SHOWING THE MOST DRYING...BUT AM NOT TOTALLY CONVINCED THAT WE WILL COMPLETELY GIVE UP ON THUNDERSTORMS DURING ANY OF THE EXTENDED PERIOD. A LOT OF THIS WILL DEPEND ON THE TRACK OF HURRICANE ILEANA. THE ECMWF AND THE NHC SHOW THIS STORM TO TRACK NORTHWEST ALONG THE BAJA COAST AND EVENTUALLY TURN MORE WESTERLY AS HIGH PRESSURE PUSHES WEST. THE GFS SEEMS TO GO AGAINST THIS AND TRACK THE SYSTEM ALMOST DUE NORTH BEFORE TURNING INLAND OVER SOUTHERN CALIFORNIA. THIS WOULD BRING A SIGNIFICANT AMOUNT OF MOISTURE BACK INTO THE AREA AND BRING MORE WIDESPREAD STORMS EACH AFTERNOON STARTING MONDAY. AM GOING TO LEAN MORE WITH THE ECMWF SOLUTION AND GRADUALLY SHOW A DRYING TREND FROM WEST TO EAST AND KEEPING THE HIGHEST POPS OVER MOHAVE COUNTY. DID NOT MAKE ANY SIGNIFICANT CHANGES TO THE FORECAST. TEMPERATURES ARE EXPECTED TO REMAIN NEAR TO SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...FOR MCCARRAN... FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...FOR MCCARRAN...THUNDERSTORMS ARE ONCE AGAIN EXPECTED TO DEVELOP THIS AFTERNOON OVER THE MOUNTAINS AND POSSIBLY DRIFT INTO THE VALLEY. ERRATIC OUTFLOW WINDS GUSTING UP TO 35 KTS WILL ALSO BE POSSIBLE. MOST OF THE THUNDERSTORM ACTIVITY WILL QUICKLY DISSIPATE AFTER SUNSET. OUTSIDE OF ANY THUNDERSTORM ACTIVITY WINDS WILL GENERALLY BE FROM THE SOUTH AROUND 8-10KTS. TEMPERATURES ARE EXPECTED TO BE AOA 100F BETWEEN 21Z-03Z. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED TO SCT TSRA WILL AGAIN DEVELOP THIS AFTERNOON OVER MUCH OF THE REGION WITH GUSTY AND ERRATIC OUTFLOW WINDS UP TO 35 KTS POSSIBLE. MOST OF THE ACTIVITY IS EXPECTED BETWEEN 20Z-03Z AND SHOULD QUICKLY DIMINISH AFTER SUNSET. OUTSIDE OF THUNDERSTORM INFLUENCES WINDS WILL FAVOR A SOUTHERLY DIRECTION BETWEEN 8-14KTS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && UPDATE...WOLCOTT PREV DISCUSSION...SALMEN/GORELOW HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 513 AM PDT THU AUG 30 2012 AZZ001>003-036-CAZ524>527-NVZ015-016-018>022-310315- 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- 513 AM PDT THU AUG 30 2012 /513 AM MST THU AUG 30 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS PRODUCING AREAS OF HEAVY RAIN AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SCATTERED THUNDERSTORMS FRIDAY AND SATURDAY PRODUCING AREAS OF HEAVY RAIN...SMALL HAIL AND GUSTY WINDS. A FLASH FLOOD WATCH MAY BE NECESSARY FOR FRIDAY AND POSSIBLY SATURDAY AS WELL. THE HEAVY RAIN...WIND THREAT SHIFTS EAST INTO MAINLY MOHAVE COUNTY SUNDAY AND EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME HOWEVER... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. CAZ519>523-NVZ014-017-310315- 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- 513 AM PDT THU AUG 30 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT ISOLATED THUNDERSTORMS PRODUCING HEAVY RAIN AND GUSTY WINDS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY ISOLATED TO SCATTERED THUNDERSTORMS FRIDAY PRODUCING HEAVY RAIN... SMALL HAIL AND GUSTY WINDS. NO HAZARDOUS WEATHER IS EXPECTED OVER THE WEEKEND INTO EARLY NEXT WEEK. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT ANTICIPATED AT THIS TIME HOWEVER... SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1045 AM PDT THU AUG 30 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0430 PM HEAVY RAIN 4 ESE WEST WIND AERO 34.12N 115.85W
08/29/2012 M1.02 INCH SAN BERNARDINO CA TRAINED SPOTTER
1.02 INCHES OF RAIN FELL IN A 3 HOUR PERIOD STARTING AT
1630.
&&
METZGERThe Las Vegas radar (KESX), 65 km away, was scanning. The volume nearest the first event began at 19:39 UTC.
1 flash flood. Local standard time, as filed.
One foot of water flowed over both Bonnie Springs Road and the Spring Mountain Ranch State Park access road just west of Highway 159.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2012Every state in 2012This day in weather historyWarnings in Nevada, August 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: 400931.