A strong low pressure system combined with lingering monsoon moisture to produce flash flooding and severe weather over the Mojave Desert.
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.
A strong low pressure system combined with lingering monsoon moisture to produce flash flooding and severe weather over the Mojave Desert.
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 Oct 11, 2:30 PM PST, 30 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 330 PM PDT THU OCT 11 2012 .SYNOPSIS...A STRONG LOW PRESSURE SYSTEM MOVING INTO SOUTHERN CALIFORNIA WILL BRING SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS THROUGH FRIDAY. WITH COLDER AIR MOVING INTO THE REGION FRIDAY...MANY OF THE HIGHER ELEVATIONS ABOVE 8000 FEET WILL SEE THE FIRST SNOW OF THE YEAR. TEMPERATURES WILL REMAIN SEVERAL DEGREES BELOW NORMAL FRIDAY...BUT DRY WEATHER WITH A WARMING TREND CAN BE EXPECTED FOR THE WEEKEND AND THE FIRST HALF OF NEXT WEEK. && .SHORT TERM...UPPER LOW CURRENTLY JUST OFF THE CALIFORNIA COAST WILL GRADUALLY MOVE INLAND THIS EVENING AND ACROSS SOUTHERN NEVADA FRIDAY MORNING. SHOWERS AND THUNDERSTORMS AHEAD OF THE LOW WILL CONTINUE TO AFFECT THE REGION THROUGH FRIDAY. MAIN BAND OF SHRA/TRSA LOCATED FROM SOUTHERN MOHAVE COUNTY THROUGH NORTHEAST CLARK COUNTY AND INTO LINCOLN COUNTY. THIS BAND HAS BEEN PRETTY PERSISTENT AND IS EXPECTED TO SLOWLY PUSH EAST/NORTHEAST OVERNIGHT. A SECONDARY AREA HAS DEVELOPED IN THE MORE UNSTABLE AIRMASS OF EASTERN SAN BERNARDINO...SOUTHERN NYE...SOUTHERN INYO...AND SOUTHWEST CLARK COUNTIES WHICH WILL ALSO PERSIST INTO TONIGHT. THESE STORMS HAVE BEEN MAINLY HEAVY RAIN PRODUCING STORMS...BUT THIS IS ALSO THE BETTER AREA OF SEEING ANY SEVERE STORMS WITH FAIRLY LOW LI VALUES AND HIGH CAPE VALUES. THIS AREA ALSO SAW NEARLY FULL SUN FOR MUCH OF THE DAY. SHOWERS AND THUNDERSTORM ARE ALSO DEVELOPING OVER SOUTHWEST SAN BERNARDINO JUST AHEAD OF THE LOW ITSELF. THESE WILL ALSO PERSIST THROUGH TONIGHT AS THE LOW CONTINUES ITS EASTERLY TRACK. THE MORE WIDESPREAD SHOWERS ARE EXPECTED OVER THE NORTH TOMORROW WITH MORE CONVECTIVE SCATTERED TYPE SHOWERS CLOSER TO THE LOW CENTER. 700MB TEMPERATURES WILL DROP TO AROUND -4 DEG C WHICH WOULD BRING SNOW LEVELS DOWN TO AROUND 7500 FEET. EXPECTING SOME SNOW ACCUMULATIONS IN THE SPRING MOUNTAINS ABOVE 8000 FEET WHERE 2-4 INCHES WILL BE POSSIBLE. TEMPERATURES WILL ALSO BE HELD ONCE AGAIN TO SEVERAL DEGREES BELOW NORMAL. THE LOW IS FORECAST TO MOVE INTO NORTHERN ARIZONA/SOUTHERN UTAH LATE FRIDAY AFTERNOON WITH SHOWERS ENDING ACROSS THE AREA WITH THE EXCEPTION OF SOME WRAP AROUND MOISTURE POSSIBLE OVER LINCOLN COUNTY INTO SATURDAY MORNING. TEMPERATURES WILL START TO WARM ALONG WITH A DRYING TREND SATURDAY AS HIGH PRESSURE WORKS INTO THE REGION. .LONG TERM...BENIGN CONDITIONS ARE EXPECTED THROUGH THE EXTENDED AS DRY WESTERLY FLOW ALOFT REMAINS IN PLACE ACROSS THE DESERT SOUTHWEST THROUGH THE PERIOD. CLOUD COVERAGE WILL BE LIMITED...AND WITH MINIMAL CHANGE TO HEIGHTS...VERY LITTLE DAY TO DAY CHANGE IN TEMPERATURES CAN BE EXPECTED...WITH VALUES APPROXIMATELY 5 DEGREES ABOVE NORMAL ON AVERAGE. && .AVIATION...FOR MCCARRAN...BKN CIGS AOA 7K-10K FEET THIS EVENING WITH BASES LOWERING TO 4K-6K FEET IN AND NEAR ANY SHRA/TSRA. A DOWNWARD TREND IN THE COVERAGE OF SHRA/TSRA IN AND AROUND THE LAS VEGAS VALLEY SHOULD TAKE PLACE FROM 06Z TO 14Z FRIDAY. WINDS THIS EVENING THROUGH FRIDAY EVENING SHOULD BE MAINLY SOUTHWEST AT 6-12 KTS WITH OCCASIONAL GUSTS TO 18 KTS MAINLY ON FRIDAY AFTERNOON. SHRA/TSRA COULD RESULT IN GUSTY AND ERRATIC WINDS AT TIMES. VSBY SHOULD GENERALLY BE VFR BUT COULD LOWER TO MVFR OR BELOW IN ANY HEAVIER DOWNPOURS. DRY CONDITIONS ARE EXPECTED FROM FRIDAY NIGHT THROUGH THE WEEKEND WITH NO OPERATIONALLY SIGNIFICANT CLOUDS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...SCT SHRA/TSRA THROUGH 14Z FRIDAY MAINLY ACROSS MOHAVE...LINCOLN...CLARK...CENTRAL/SOUTHERN NYE AND EASTERN SAN BERNARDINO COUNTIES WITH ISOLATED ACTIVITY ELSEWHERE. CIGS WILL MAINLY BE 7K-12K FEET AWAY FROM ANY HEAVIER SHRA/TSRA. UNDER ANY HEAVIER DOWNPOURS CIGS MAY LOWER TO 3K-6K FEET AND VSBY MAY DROP TO MVFR OR LOWER. AFTER 14Z FRIDAY...SCT SHRA/TSRA MAINLY IN LINCOLN AND NORTHERN MOHAVE COUNTIES WITH ISOLATED SHRA/TSRA IN CLARK...SOUTHERN MOHAVE AND CENTRAL/SOUTHERN NYE COUNTIES. SNOW LEVELS SHOULD BE AROUND 7K-8K FEET TONIGHT AND ON FRIDAY. WINDS MAY BECOME GUSTY AND ERRATIC NEAR ANY SHRA/TSRA BUT OTHERWISE SHOULD FAVOR DIURNAL TRENDS AT 6-12 KTS. GUSTS OF 22-28 KTS ARE EXPECTED AT KDAG ESPECIALLY ON FRIDAY. DRY CONDITIONS WITH NO OPERATIONALLY SIGNIFICANT CLOUDS ARE EXPECTED FOR THE WEEKEND. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && GORELOW/STACHELSKI HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 310 AM PDT THU OCT 11 2012 AZZ001>003-036-CAZ519>527-NVZ014>022-120700- 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- 310 AM PDT THU OCT 11 2012 /310 AM MST THU OCT 11 2012/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT A STRONG LOW PRESSURE SYSTEM OFF THE SOUTHERN CALIFORNIA COAST THIS MORNING WILL MOVE INLAND TODAY AND TO FAR SOUTHERN NEVADA LATE TONIGHT. WIDESPREAD SHOWERS AND ISOLATED TO SCATTERED THUNDERSTORMS ARE EXPECTED OVER SOUTHERN NEVADA AND NORTHWEST ARIZONA. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED OVER SOUTHEAST CALIFORNIA. RAINFALL AMOUNTS UP TO AN INCH ARE POSSIBLE IN PORTIONS OF NEVADA AND ARIZONA. LOCALLY HEAVY RAIN IS POSSIBLE WITH STRONGER THUNDERSTORMS ALONG WITH WIND GUSTS UP TO 60 MPH. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL LINGER FRIDAY BUT WILL GRADUALLY END FROM SOUTHWEST TO NORTHEAST FRIDAY AFTERNOON AND FRIDAY NIGHT. DRY CONDITIONS WITH A WARMING TREND CAN BE EXPECTED SATURDAY THROUGH WEDNESDAY. .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
1007 AM PDT THU OCT 11 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0957 AM FLASH FLOOD 3 SSE NEEDLES 34.77N 114.60W
10/11/2012 SAN BERNARDINO CA PUBLIC
HIGHWAY 95 WAS REPORTED CLOSED AT FIVE MILE ROAD DUE TO
FLASH FLOODING.
&&
STACHELSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1034 AM PDT THU OCT 11 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1015 AM SNOW 2 W ASPENDELL 37.22N 118.62W
10/11/2012 M6.0 INCH INYO CA TRAINED SPOTTER
THE LAKE SABRINA BOAT RAMP MEASURED 6 INCHES OF SNOW FROM
645 AM THROUGH 1015 AM THIS MORNING AT AN ELEVATION OF
9144 FEET. SNOW WAS STILL FALLING LIGHTLY AT THE TIME OF
OBSERVATION.
&&
CS/RMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1043 AM PDT THU OCT 11 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1038 AM HEAVY RAIN 5 NNW SUMMERLIN 36.27N 115.34W
10/11/2012 M1.77 INCH CLARK NV MESONET
A STORM TOTAL OF 1.77 INCHES OF RAIN WAS MEASURED AT AN
AUTOMATED RAIN GAUGE OPERATED BY THE CLARK COUNTY
REGIONAL FLOOD CONTROL DISTRICT JUST WEST OF THE
INTERSECTION OF ANN ROAD AND THE 215 BELTWAY SINCE RAIN
BEGAN AROUND 3 PM ON 10/10/12.
1038 AM HEAVY RAIN 1 S SUMMERLIN SOUTH 36.12N 115.33W
10/11/2012 M1.77 INCH CLARK NV MESONET
A TOTAL OF 1.77 INCHES WAS MEASURED BY AN AUTOMATED GAUGE
OPERATED BY THE CLARK COUNTY REGIONAL FLOOD CONTROL
DISTRICT NEAR TOWN CENTER AND THE 215 BELTWAY SINCE THE
RAIN BEGAN AROUND 3 PM ON 10/10/12.
&&
STACHELSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1212 PM PDT THU OCT 11 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1210 PM HEAVY RAIN 10 NW CENTENNIAL HILLS 36.38N 115.38W
10/11/2012 M2.05 INCH CLARK NV MESONET
AN AUTOMATED RAIN GAUGE OPERATED BY THE CLARK COUNTY
REGIONAL FLOOD CONTROL DISTRICT MEASURED 2.05 INCHES OF
RAIN SINCE 3 PM ON 10/10/12 NEAR HIGHWAY 95 NORTH OF KYLE
CANYON ROAD.
&&
STACHELSKIPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1228 PM PDT THU OCT 11 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0930 AM SNOW 1 WNW ASPENDELL 37.24N 118.60W
10/11/2012 E4.0 INCH INYO CA TRAINED SPOTTER
A SPOTTER ESTIMATED 4 INCHES OF SNOW IN ASPENDELL ENDING
AT 930 AM THIS MORNING AT 8500 FEET.
&&
STACHELSKIThe Las Vegas radar (KESX), 73 km away, was scanning. The volume nearest the first event began at 22:59 UTC.
6 flash flood, 3 hail. Local standard time, as filed.
Part of the Red Rock Scenic Loop was washed out.
The main road to Spring Mountain Ranch State Park flooded near the park entrance.
Several roads in Sandy Valley had mud washed onto them.
Several inches of water and debris were over Highway 159.
Water and debris were crossing Arroyo Road in Blue Diamond.
Nickel to quarter size hail was reported by several sources as it tracked from Anthem to East Las Vegas. One car windshield was cracked.
Flash flooding affected much of the Las Vegas Valley. Numerous streets were flooded, and at least one freeway on ramp was closed. Water entered one home, and there were at least four swift water rescues.
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, October 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: 411351, 411354, 411358, 411362, 411363, 411364, 411365, 411367, 411366.