Monsoon moisture fueled more thunderstorms across the Mojave Desert. A few storms produced severe weather and/or flash flooding.
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 more thunderstorms across the Mojave Desert. A few storms produced severe weather and/or flash flooding.
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 18, 2:25 PM PST, 1 hour 57 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 325 PM PDT SAT AUG 18 2012 .SYNOPSIS...MOIST SOUTHERLY FLOW WILL CONTINUE ACROSS MUCH OF THE AREA THROUGH SUNDAY...LEADING TO ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS. THESE STORMS WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL AND GUSTY WINDS. NEAR NORMAL TEMPERATURES AND DRYING ACROSS THE WESTERN AREAS ARE EXPECTED EARLY NEXT WEEK. && .SHORT TERM...TODAY THROUGH TUESDAY...ISOLATED CONVECTION HAS FIRED OVER MUCH OF THE AREA THIS AFTERNOON WITH THE EXCEPTION OF WESTERN SAN BERNARDINO AND LINCOLN COUNTIES. LAPS DATA ALSO SHOWING THOSE AREAS AS BEING THE MOST STABLE AND IT LOOKS LIKE THE MAIN AREAS GOING INTO THIS EVENING WILL BE MOHAVE...NYE...INYO...AND CLARK COUNTIES. THESE STORMS HAVE BEEN MOSTLY STATIONARY AND ISOLATED FLASH FLOODING WILL BE POSSIBLE FOR THE REMAINDER OF THE AFTERNOON AND EARLY EVENING. ALTHOUGH THESE STORMS HAVE GENERALLY BEEN FORMING OVER THE MOUNTAINS...ANY OUTFLOW BOUNDARIES WILL CERTAINLY HELP GENERATE STORMS IN THE VALLEY LOCATIONS WHICH WILL BE POSSIBLE INTO THIS EVENING. LOOKS LIKE NEARLY THE SAME CONDITIONS SUNDAY AS ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP IN THE EARLY AFTERNOON OVER THE HIGHER TERRAIN AND POTENTIALLY WORK INTO THE VALLEYS BY LATE AFTERNOON DUE TO OUTFLOW BOUNDARIES. ONCE AGAIN DO NOT SEE ANY INITIAL TRIGGER FOR STORMS...SO WILL RELY ON SURFACE HEATING AND OROGRAPHICS. STORMS COULD BE MORE ORGANIZED OVER INYO AND ESMERALDA COUNTIES DUE TO HIGHER 0-6KM BULK SHEAR NUMBERS WHICH ARE BETWEEN 25-30KTS. THESE IS LESS LOW LEVEL MOISTURE IN THOSE AREAS SO STRONG WINDS WILL BE THE MAIN CONCERN THERE. SOME DRIER AIR WILL BEGIN TO WORK INTO THE REGION MONDAY AND TUESDAY AS A TROUGH OFF THE COAST STARTS TO PUSH INLAND. THIS WILL HELP TO LIMIT STORMS TO MAINLY THE EASTERN HALF OF THE CWA WHICH COULD STILL SEE HEAVY RAIN PRODUCING STORMS. TEMPERATURES THROUGH THE PERIOD ARE EXPECTED TO BE NEAR NORMAL. .LONG TERM...WEDNESDAY THROUGH SATURDAY...LITTLE CHANGE MADE TO THE EXTENDED FORECAST AS A TROUGH OFF THE WEST COAST HELPS PUSH THE HIGH FURTHER EAST. THIS WILL ALLOW FOR SOME DRIER AIR TO WORK INTO THE REGION WEDNESDAY AND LIMITING AFTERNOON CONVECTION TO MAINLY THE FAR EASTERN AREAS OF THE CWA. BY THE END OF THE WEEK MODELS ARE INDICATING THE HIGH TO PUSH WESTWARD BUT BE CENTERED OVER MAINLY NORTHERN MEXICO WHICH SHOULD KEEP ANY SIGNIFICANT MOISTURE FROM TRACKING BACK INTO THE AREA. STILL THINK THAT ENOUGH MOISTURE WILL REMAIN OVER THE FAR EASTERN AREAS OF THE CWA AND KEPT THE HIGHEST POPS OVER MAINLY MOHAVE COUNTY. TEMPERATURES LOOK TO BE SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...FOR MCCARRAN...THUNDERSTORMS HAVE ONCE AGAIN FIRED IN THE MOUNTAINS SURROUNDING LAS VEGAS AND THIS IS EXPECTED TO CONTINUE INTO THIS EVENING AND ISOLATED THUNDERSTORMS ARE EXPECTED IN ALL APPROACH CORRIDORS. THUNDERSTORMS WILL GRADUALLY DIMINISH AFTER 04Z...BUT ISOLATED STORMS ARE STILL POSSIBLE THROUGH 08Z. THE GENERAL WIND FLOW WILL BE SOUTH AROUND 7-9KTS...BUT GUSTY AND ERRATIC WINDS WILL BE POSSIBLE THROUGH EARLY EVENING. TEMPERATURES WILL AGAIN CLIMB ABOVE 100 DEGREES AROUND 20Z SUNDAY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...CONDITIONS WILL REMAIN FAVORABLE FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE REGION DURING THE AFTERNOON AND EVENING HOURS THROUGH SUNDAY. PREVAILING SURFACE WINDS WILL BE FROM THE SOUTH UP TO 10KTS...THOUGH GUSTY AND ERRATIC THUNDERSTORM INDUCED WINDS CAN BE EXPECTED DURING THE LATE AFTERNOON AND EARLY EVENING HOURS. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && GORELOW HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 517 AM PDT SAT AUG 18 2012 AZZ001>003-036-CAZ519>527-NVZ014>022-190330- 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- 517 AM PDT SAT AUG 18 2012 /517 AM MST SAT AUG 18 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT VERY MOIST SOUTHERLY FLOW WILL BE OVER THE REGION TODAY AND TONIGHT RESULTING IN SCATTERED MAINLY AFTERNOON AND EVENING THUNDERSTORMS. GUSTY WINDS MAY BE SEEN FROM THESE THUNDERSTORMS... HOWEVER THE MAIN CONCERN WILL BY BRIEF HEAVY RAINFALL WHICH MAY PRODUCE ISOLATED FLASH FLOODING. THE MAIN AREA OF THUNDERSTORMS WILL BE SOUTH OF A LINE FROM WESTERN SAN BERNARDINO NORTHEAST INTO SOUTHERN LINCOLN COUNTY. .DAYS TWO THROUGH SEVEN...SUNDAY THROUGH FRIDAY VERY MOIST FLOW WILL CONTINUE ON SUNDAY FOR SCATTERED AFTERNOON AND EVENING THUNDERSTORMS WITH LOCALLY HEAVY RAINFALL POSSIBLE... HOWEVER DRYING WILL BEGIN TO BE SEEN FROM THE WEST. THIS DRIER FLOW WILL THEN TEND TO KEEP THE MAIN THUNDERSTORM ACTIVITY OVER MOHAVE COUNTY FROM MONDAY THROUGH FRIDAY. .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.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1233 PM PDT SAT AUG 18 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1222 PM HEAVY RAIN W HUALAPAI MOUNTAIN 35.10N 113.89W
08/18/2012 M1.10 INCH MOHAVE AZ TRAINED SPOTTER
HUALAPAI MOUNTAIN ALERT 1.10 INCHES OF RAINFALL. SPOTTER
REPORTED PEA-SIZED HAIL COVERING THE GROUND. WATER
RUNNING 4 TO 5 INCHES DEEP AT CAMPGROUND.
&&
BPPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
108 PM PDT SAT AUG 18 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1235 PM HEAVY RAIN 2 ESE MT. CHARLESTON 36.27N 115.59W
08/18/2012 E1.00 INCH CLARK NV CO-OP OBSERVER
NEVADA DIVISION OF FORESTRY FIRE DEPARTMENT REPORTS AN
ESTIMATED INCH OF RAIN FELL IN A 20 MINUTE PERIOD. AN
ESTIMATED 2-3 INCHES OF WATER WAS FLOWING DOWN KYLE
CANYON ROAD.
&&
METZGERPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
509 PM PDT SAT AUG 18 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0504 PM HEAVY RAIN SE BEATTY 36.91N 116.76W
08/18/2012 E1.00 INCH NYE NV TRAINED SPOTTER
SPOTTER REPORTS 3 INCHES OF WATER FLOWING DOWN 2ND ST IN
BEATTY. ABOUT 1 INCH OF RAIN FELL IN THE HOUR FROM 4 TO 5
PM.
&&
METZGERThe national radar mosaic for the moment the first event began.
1 flash flood. Local standard time, as filed.
Highway 190 was washed out and closed at mile marker 79.
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, 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: 397534.