Monsoon moisture fueled another round of thunderstorms over the Mojave Desert and southern Great Basin. Several storms produced severe weather and 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 another round of thunderstorms over the Mojave Desert and southern Great Basin. Several storms produced severe weather and 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 14, 2:06 PM PST, 52 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 306 PM PDT TUE AUG 14 2012 .SYNOPSIS...THUNDERSTORM COVERAGE WILL DECREASE THROUGH THURSDAY AS DRIER AIR MOVES IN FROM THE WEST. MONSOON MOISTURE IS EXPECTED TO MOVE BACK INTO THE REGION BY THE WEEKEND...RESULTING IN AN INCREASE IN THUNDERSTORM CHANCES. TEMPERATURES WILL REMAIN ABOVE NORMAL. && .SHORT TERM...SOMEWHAT DRIER AND MORE STABLE AIR HAS STARTED TO MOVE INTO THE SOUTHWEST PART OF THE FORECAST AREA BUT THERE WILL BE A CHANCE OF THUNDERSTORMS ACROSS MAINLY THE NORTH AND EAST THROUGH THIS EVENING. THE DRYING AND STABILIZING TREND WILL CONTINUE WEDNESDAY INTO THURSDAY AS THE 500 MB HIGH MOVES FROM SOUTHEAST ARIZONA TODAY TO THE SOUTHERN PART OF THE FORECAST AREA RESULTING IN A MORE WESTERLY FLOW OVER THE AREA. THERE WILL STILL BE ENOUGH MOISTURE FOR A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS AROUND THE FAR NORTHERN AND EASTERN PERIPHERY OF THE FORECAST AREA BOTH WEDNESDAY AND THURSDAY. MODELS SHIFT THE HIGH PRESSURE CENTER JUST NORTH OF THE AREA FRIDAY ALLOWING AN INCREASE IN MOISTURE FROM THE EAST INTO THE SOUTHERN PART OF THE FORECAST AREA. THE BEST CHANCE OF THUNDERSTORMS FRIDAY AFTERNOON AND EVENING WILL THEREFORE BE ACROSS SOUTHERN MOHAVE AND SAN BERNARDINO COUNTIES WITH JUST A SLIGHT CHANCE OVER THE MOUNTAINS TO THE NORTH OF THAT AREA. TEMPERATURES WILL REMAIN A LITTLE ABOVE NORMAL THROUGH FRIDAY WITH THE HIGH IN THE GENERAL VICINITY. .LONG TERM...MINIMAL CHANGE WAS NEEDED IN THE EXTENDED AS MODELS SHOW RELATIVELY GOOD AGREEMENT IN THE LONG TERM. THE EC...GFS ENSEMBLE MEAN...AND GEM ALL DEPICT HIGH PRESSURE AS THE DOMINANT FEATURE THROUGH THE PERIOD...BUT IN THE ABSENCE OF ANY FEATURE TO FLUSH OUT ANY MOISTURE ALREADY IN PLACE...THERE WILL BE SUFFICIENT MOISTURE FOR AT LEAST A CHANCE OF AFTERNOON/EVENING THUNDERSTORM DEVELOPMENT OVER HIGHER TERRAIN. TEMPERATURES ARE FORECAST TO WARM SLIGHTLY IN THE MID LEVELS BY THE END OF THE WEEKEND AND INTO NEXT WEEK...BUT A LIGHT INCREASE IN MID LEVEL MOISTURE IS ALSO EXPECTED...SO OVERALL INSTABILITY LOOKS TO BE VERY SIMILAR TO WHAT WHAT HAS BEEN OBSERVED OVER THE PAST SEVERAL DAYS. IN GENERAL..THE BEST CHANCE FOR ANY DEVELOPMENT WILL BE ACROSS MOHAVE COUNTY AND SOUTHERN SAN BERNARDINO COUNTY. TEMPERATURES WILL REMAIN SLIGHTLY ABOVE NORMAL THROUGH THE PERIOD. && .AVIATION...FOR MCCARRAN...WIDELY SCATTERED THUNDERSTORMS ARE BEGINNING TO DEVELOP ACROSS THE REGION...WHICH WILL CREATE OUTFLOW BOUNDARIES THAT WILL INFLUENCE THE SURFACE WINDS. ALTHOUGH THERE IS A SLIGHT CHANCE OF A THUNDERSTORM COMING WITHIN THE AERODROME...WITH MAIN IMPACT WILL BE THESE OUTFLOW BOUNDARIES. OVERALL...THUNDERSTORM ACTIVITY WILL BEGIN TO DIMINISH EARLY THIS EVENING...WITH WINDS REMAINING BELOW 10KTS OUT OF THE SOUTHWEST. THUNDERSTORM ACTIVITY IS EXPECTED TO REMAIN WELL TO THE EAST TOMORROW. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...WIDELY SCATTERED THUNDERSTORMS ARE BEGINNING TO DEVELOP ACROSS THE REGION...WHICH WILL CREATE OUTFLOW BOUNDARIES THAT WILL INFLUENCE THE SURFACE WINDS. OUTSIDE OF ANY THUNDERSTORM INFLUENCE..WINDS WILL BE...FAVOR A SOUTHWESTERLY DIRECTION AROUND 10KTS. THUNDERSTORM ACTIVITY SHOULD DIE OFF THIS EVENING WITH DECREASING CLOUDS AND WINDS. .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && HARRISON/KENNEDY HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 522 AM PDT TUE AUG 14 2012 AZZ001>003-036-CAZ519>527-NVZ014>022-150700- 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- 522 AM PDT TUE AUG 14 2012 /522 AM MST TUE AUG 14 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...SOUTHEAST CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS CAN BE EXPECTED DURING THE AFTERNOON AND EVENING HOURS THOUGH FEWER STORMS WILL BE OBSERVED THAN YESTERDAY FROM THE WESTERN MOJAVE DESERT TO THE COLORADO RIVER VALLEY. THUNDERSTORMS WILL BE MOST PREVALENT AROUND AN ARC EXTENDING FROM THE SOUTHERN SIERRA...ACROSS CENTRAL NEVADA AND DOWN THROUGH NORTHWEST ARIZONA. THE PRIMARY HAZARD ASIDE FROM LIGHTNING WILL BE THE POTENTIAL FOR STRONG WIND GUSTS WITH SOME STORMS. A FEW STORMS COULD ALSO PRODUCE HEAVY RAIN LEADING TO FLASH FLOODING. STORM MOVEMENT WILL BE THE NORTH OR NORTHEAST AT 5 TO 15 MPH. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THUNDERSTORM COVERAGE WILL DECREASE CONSIDERABLY ACROSS MOST OF THE AREA WEDNESDAY AND THURSDAY THEN MONSOONAL MOISTURE IS EXPECTED TO INCREASE GOING INTO THE WEEKEND FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE REGION. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED TODAY. HOWEVER...SPOTTERS ARE ENCOURAGED TO REPORT ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. JA
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1025 AM PDT TUE AUG 14 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM HEAVY RAIN 7 N DEATH VALLEY JUNCTI 36.41N 116.42W
08/13/2012 E0.25 INCH NYE NV PARK/FOREST SRVC
ONE TO TWO INCHES OF WATER WERE ACROSS THE HIGHWAY AT THE
STATELINE NEAR AMARGOSA VALLEY.
&&
STACHELSKIThe Las Vegas radar (KESX), 38 km away, was scanning. The volume nearest the first event began at 22:56 UTC.
1 flash flood. Local standard time, as filed.
Water, rocks, and mud were on the roads near the intersection of Arroyo Grande and Horizon Ridge.
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: 397528.