Several virga shafts produced isolated high winds over the Las Vegas Valley. Two of the dry microbursts caused damage.
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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.
Several virga shafts produced isolated high winds over the Las Vegas Valley. Two of the dry microbursts caused damage. No lightning was observed.
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 8, 2:16 PM PST, 1 hour 44 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE LAS VEGAS NV 316 PM PDT THU SEP 8 2011 .SYNOPSIS...ISOLATED SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH THIS EVENING...THEN INCREASE IN COVERAGE FRIDAY AFTERNOON AND EVENING. DAMAGING WINDS WILL BE THE MAIN THREAT. A SIGNIFICANT INCREASE IN SHOWERS AND THUNDERSTORMS CAN BE EXPECTED OVER THE WEEKEND...WITH HEAVY RAIN AND HAIL ALSO BECOMING THREATS. LESS THUNDERSTORM COVERAGE IS EXPECTED BY THE MIDDLE OF NEXT WEEK. && .SHORT TERM...SATELLITE AND AREA RADARS SHOW DEEPER CLOUDS/VIRGA DEVELOPING OVER THE MOUNTAINS IN MOST OF OUR CWA...WHILE AN AREA OF THUNDERSTORMS MOVES SLOWLY EAST ACROSS THE NEVADA NATIONAL SECURITY SITE ON THE FRONT SIDE OF THE LOW PRESSURE SYSTEM DIGGING THROUGH WESTERN NEVADA. THIS LOW HAS NO CHANCE TO MOVE FARTHER EAST THANKS TO THE HUGE RIDGE OVER THE PLAINS OF THE NORTHERN U.S. AND SOUTHERN CANADA...SO IT WILL MEANDER OVER THE DESERT SOUTHWEST THROUGH THE SHORT TERM AND BEYOND. THIS WILL MEAN CHANCES FOR MAINLY AFTERNOON AND EVENING THUNDERSTORMS THROUGH FRIDAY...PRIMARILY FOCUSED BY THE HIGHER TERRAIN AND ANY OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FLOATING AROUND. THE MOISTURE IS LIMITED TO A SHALLOW LAYER IN THE MID LEVELS...WITH MODEL FORECAST SOUNDINGS SHOWING A DEEP DRY LAYER UNDERNEATH WITH DRY ADIABATIC LAPSE RATES. THIS WILL LEAD TO A SIGNIFICANT THREAT OF DAMAGING WINDS FROM ANY RAIN OR VIRGA SHAFT WHICH CAN PENETRATE DOWNWARD INTO THIS DRY/POTENTIALLY COLD LAYER. THINGS CHANGE SOMEWHAT OVER THE WEEKEND AS THE MAIN LOW CENTER RETROGRADES WEST TO THE CALIFORNIA COAST. THIS WILL BRING SOUTHERLY FLOW INTO OUR CWA...WHICH WILL PULL IN DEEPER MOISTURE...CAUSING THE MAIN THREAT TO TRANSITION TO MORE OF A HYBRID HEAVY RAIN/WET MICROBURST SCENARIO RATHER THAN THE DRY MICROBURST SCENARIO OF FRIDAY. THIS TRANSITION SEEMS A LITTLE SLOWER IN THIS MODEL RUN THAN PREVIOUS RUNS...SO SATURDAY COULD END UP GOING EITHER WAY. HIGH TEMPERATURES WILL BE DROPPING DAY BY DAY AS CLOUDS AND PRECIP CHANCES INCREASE. POINT TEMPERATURES WILL BE HIGHLY DEPENDENT ON THE LOCATION AND TIMING OF THUNDERSTORMS. .LONG TERM...MONDAY THROUGH THURSDAY...THE UPPER TROUGHING THAT WILL HANG OVER THE REGION IN THE EXTENDED IS THE MAIN STORY. THIS WILL KEEP THE MAJORITY OF THE EXTENDED PERIOD WITH A DECENT CHANCE OF RAIN SHOWERS OR THUNDERSTORMS ALONG WITH EXTENSIVE CLOUD COVER. MODELS IN GOOD AGREEMENT ON THE PATTERN EXCEPT TOWARDS THE LAST DAY THURSDAY. PEAK POP ACTIVITY SHOULD DIURNALLY BE DURING THE DAY DUE TO HEATING BUT THE POSSIBILITY OF NIGHT TIME RAIN OR THUNDERSTORMS CAN NOT BE RULED OUT DUE TO THE DYNAMICS FROM THE LOW/TROUGH. FROM WEDNESDAY ONWARDS I HAVE SHOWN THE POPS DECREASING AS THE TROUGH IS PROGGED TO MOVE EAST WITH THE EXCEPTION OF THE ECMWF WHICH EJECTS A WAVE WHILE THE PARENT TROUGH IS EXPECTED TO RETROGRADE. WENT MORE WITH THE GFS IDEA AND HAVE POPS DECREASED EVEN MORE ON THURSDAY. TEMPERATURES SHOULD REMAIN NEAR NORMAL. AS FOR TROPICAL STORM NATE...MODELS WILDLY DIVERGENT ON TRACK OF NATE AND NHC HAS DOUBTS ABOUT LONG RANGE...SO LEFT OUT ANY IDEAS OF ITS TRACK HAVING ANY INFLUENCE ON OUR AREA FOR NOW. && .AVIATION...FOR MCCARRAN...FOR THE REST OF THIS AFTERNOON AND EVENING EXPECT NO SIGNIFICANT WEATHER ASIDE FROM FLAKY WINDS THIS AFTERNOON. WINDS THIS AFTERNOON WILL BE HIGHLY VARIABLE IN DIRECTION BUT WILL FAVOR THE SOUTHEAST. THIS EVENING THEY WILL BE THE USUAL SOUTHWEST DRAINAGE WINDS. CLOUD COVER WILL INCREASE SLOWLY TONIGHT AND THROUGH FRIDAY. FOR NOW EXPECT NO SIGNIFICANT CEILING HEIGHT CRITERIA TO BE MET. ALONG WITH THE CLOUD COVER INCREASE THERE WILL BE THUNDERSTORMS DEVELOPING OVER AND NEAR THE LOCAL MOUNTAIN RANGES. CHANCES OF ONE BEING OVER KLAS ARE TOO LOW TO MENTION IN THE TAF. LOOKING BEYOND FRIDAY CHANCES FOR RAIN OR THUNDER AT KLAS ARE INCREASED ON SATURDAY AND SUNDAY. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...THUNDERSTORM ACTIVITY WILL BE MAINLY CONFINED TO SOUTHERN NYE AND NORTHEAST SAN BERNARDINO COUNTY THIS AFTERNOON. IT IS POSSIBLE TO SEE ISOLATED THUNDERSTORMS OVER MOUNTAIN AREAS ELSEWHERE THIS AFTERNOON UNTIL SUNSET. CLOUD COVER WILL GRADUALLY INCREASE DURING THE DAY FRIDAY AS AN UPPER LEVEL TROUGH DEVELOPS OVER THE AREA AND FORMS A LOW OVER CALIFORNIA BY SATURDAY. THE AREA WILL SEE AFTERNOON THUNDERSTORMS PRIMARILY OVER MOUNTAIN AREAS FRIDAY AFTERNOON. WINDS WILL BE LIGHT OVER THE AREA FRIDAY EXCEPT NEAR THUNDERSTORMS. THIS WEEKEND WILL SEE GREATLY INCREASED THUNDERSTORM AND RAIN SHOWER COVERAGE OVER THE AREA. && .VEF WATCHES/WARNINGS/ADVISORIES... NV...NONE. AZ...NONE. CA...NONE. && MORGAN/JACQUES HTTP://WEATHER.GOV/LASVEGAS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE LAS VEGAS NV 310 AM PDT THU SEP 8 2011 AZZ001>003-036-CAZ519>527-NVZ014>022-090700- 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 SEP 8 2011 /310 AM MST THU SEP 8 2011/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHWEST ARIZONA...CALIFORNIA AND SOUTHERN NEVADA. .DAY ONE...TODAY AND TONIGHT A LOW PRESSURE SYSTEM MOVING INTO NEVADA TODAY WILL DESTABILIZE THE AIR MASS ALLOWING FOR ISOLATED THUNDERSTORM DEVELOPMENT OVER THE HIGHER TERRAIN OF MOHAVE COUNTY AND THE SOUTHERN GREAT BASIN. GUSTY WINDS WILL BE THE PRIMARY THREAT FROM THOSE STORMS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THUNDERSTORM COVERAGE WILL GRADUALLY INCREASE FRIDAY THROUGH SATURDAY AS THE LOW PRESSURE SYSTEM MOVES INTO CALIFORNIA. SCATTERED THUNDERSTORMS ARE EXPECTED OVER THE MOUNTAINS FRIDAY WITH ISOLATED THUNDERSTORMS OVER MUCH OF THE DESERT AREA. SCATTERED TO NUMEROUS THUNDERSTORMS ARE THEN EXPECTED ACROSS THE ENTIRE AREA SATURDAY AS THE AIR MASS CONTINUES TO MOISTEN AND DYNAMICS FROM THE UPPER LOW INCREASE. STORMS ON SATURDAY WILL HAVE THE POTENTIAL TO PRODUCE HEAVY RAIN...HAIL AND GUSTY WINDS. THUNDERSTORM CHANCES WILL CONTINUE SUNDAY THROUGH WEDNESDAY AS THE LOW PRESSURE SYSTEM REMAINS NEARLY STATIONARY. .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.
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
The Nellis AFB ASOS measured a wind gust to 67 mph which collapsed an aircraft shelter, causing minor injuries to eight personnel. A short time later, another microburst uprooted a 30-foot mesquite tree in Henderson.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2011Every state in 2011This day in weather historyWarnings in Nevada, September 2011
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: 334024.