A major surge of monsoon moisture brought an outbreak of thunderstorms to the Mojave Desert and southern Great Basin, with the most activity on the 3rd and 4th. Widespread flash flooding and severe weather occurred.
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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.
A major surge of monsoon moisture brought an outbreak of thunderstorms to the Mojave Desert and southern Great Basin, with the most activity on the 3rd and 4th. Widespread flash flooding and severe weather 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 1, 3:19 PM MST, 1 hour 11 minutes earlier.
AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE LAS VEGAS NV 319 PM PDT FRI AUG 1 2014 .SYNOPSIS...INCREASING THUNDERSTORM COVERAGE WITH THE POTENTIAL FOR HEAVY RAIN CAN BE EXPECTED SATURDAY AND SUNDAY AS DEEPER MOISTURE AND A POTENT UPPER LEVEL DISTURBANCE MOVE IN FROM THE SOUTH. THIS WILL BE FOLLOWED BY A DRYING TREND FROM SOUTHWEST TO NORTHEAST EARLY NEXT WEEK. && .SHORT TERM...THROUGH SUNDAY NIGHT...ISOLATED TERRAIN DRIVEN THUNDERSTORMS THIS AFTERNOON WILL BECOME MORE EXTENSIVE SATURDAY AFTERNOON THROUGH SUNDAY AS ABUNDANT MOISTURE AND A LARGE UPPER LOW MOVE UP FROM BAJA CALIFORNIA AND NORTHWEST MEXICO. AS THE CLOSED LOW APPROACHES SATURDAY AFTERNOON...CYCLONIC FLOW ON ITS NORTHERN PERIPHERY WILL CONVERGE WITH ANTICYCLONIC FLOW AROUND A MID LEVEL HIGH CENTERED OVER CENTRAL NEVADA. THE 12Z NAM INDICATES A SUBSTANTIAL PUSH OF LOW LEVEL MOISTURE UP THROUGH SOUTHEAST CALIFORNIA...NORTHWEST ARIZONA AND SOUTHERN NEVADA BY SATURDAY AFTERNOON WHILE THE GFS AND ECMWF ARE LESS AGGRESSIVE. HOWEVER...CONVECTIVE COMPLEXES HAVE BEEN DEVELOPING ON THE NORTHERN SIDE OF THE UPPER LOW THE PAST COUPLE EVENINGS AND THERE WILL LIKELY BE ANOTHER ONE THIS EVENING WHICH WILL HELP PUSH MOISTURE OUR WAY. THE NAM/GFS/ECMWF ARE IN GOOD AGREEMENT AT LIFTING THE CENTER OF THE LOW INTO SOUTHERN CALIFORNIA BY 12Z SUNDAY. POSITIVE VORTICITY ADVECTION WILL OCCUR SATURDAY NIGHT ACROSS THE AREA FROM LAS VEGAS SOUTHWARD WHICH SHOULD PROVIDE BROAD UPWARD FORCING TO THE MOIST AND UNSTABLE AIR MASS STREAMING INTO THE REGION. NOCTURNAL THUNDERSTORMS WILL LIKELY BE AROUND OVER THE AREA FROM CLARK COUNTY SOUTHWARD. THE GFS AND ECMWF SOLUTIONS LIFT THE LOW UP ACROSS CENTRAL CALIFORNIA INTO WESTERN NEVADA SUNDAY AND SUNDAY NIGHT WITH SUBSTANTIAL MOISTURE AND UPWARD FORCING ACROSS INYO...NYE AND ESMERALDA COUNTIES. THIS SCENARIO WILL BE FAVORABLE FOR EXTENSIVE COVERAGE OF HEAVY RAIN PRODUCING THUNDERSTORMS GRADUALLY EXPANDING FROM SOUTH TO NORTH ACROSS THE REGION FROM FROM SATURDAY AFTERNOON THROUGH SUNDAY AFTERNOON. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR THE ENTIRE AREA ACCORDINGLY. NO SIGNIFICANT CHANGES TO THE FORECAST WERE MADE BEYOND SUNDAY NIGHT. .LONG TERM...MONDAY THROUGH THURSDAY...BY MONDAY MORNING THE UPPER LEVEL LOW THAT WILL CREATE THIS WEEKEND'S UPTICK IN MONSOON ACTIVITY WILL BE SITUATED SOMEWHERE IN THE VICINITY OF CENTRAL NEVADA. ENHANCED MOISTURE [850-500MB MIXING RATIOS OF 6-8 G/KG] AND LI'S OF 0 TO -4 ARE EXPECTED TO BE IN PLACE BY MONDAY AFTERNOON ACROSS MOST OF THE REGION EXCEPT PERHAPS SOUTHERN AND WESTERN SAN BERNARDINO COUNTY. MODELS ARE IN FAIR AGREEMENT IN THE EXISTENCE OF A WEAK 40-60KT JET MOVING NORTH INTO CENTRAL/WESTERN ARIZONA AND ONE OR MORE VORTICITY LOBES ROTATING AROUND THE LOW MONDAY. THESE FEATURES HAVE THE POTENTIAL TO PROVIDE ENOUGH DYNAMICS FOR ONE MORE DAY OF FAIRLY WIDESPREAD CONVECTION ACROSS THE REGION. THE EXTENT OF ANY OVERNIGHT ACTIVITY IS MUCH LESS CERTAIN WITH SIGNIFICANT INTER-MODEL DIFFERENCES IN THE AREAS OF FORCING AFTER SUNSET. THE PRIMARY CONCERN WILL FLASH FLOODING FROM TRAINING STORMS AS STORM MOTION IS FORECAST TO BE GENERALLY NORTHEAST AT 10-15 MPH. FOR TUESDAY MORE DRYING IS EXPECTED FROM THE SOUTHWEST...HOWEVER I DID EXPAND POPS A BIT FURTHER SOUTH AS THE GENERAL CONSENSUS SHOWS SLOWER DRYING THAN WHAT WAS INDICATED 24 HOURS AGO. THE OVERALL DRYING TREND IS EXPECTED TO CONTINUE WEDNESDAY AND THURSDAY WITH PRECIP CHANCES BECOMING INCREASINGLY LIMITED TO AN AREA NORTH OF AN INDEPENDENCE-RACHEL-MESQUITE-GRAND CANYON SKYWALK ARCH. HAVE ALSO LEFT IN SLIGHT CHANCE POPS OVER THE CLARK COUNTY MOUNTAINS THROUGH THE WEEK. TEMPERATURES ARE EXPECTED TO WARM FROM 5-8 DEGREES BELOW NORMAL MONDAY TO ONLY A COUPLE DEGREES BELOW NORMAL BY WEDNESDAY. && .AVIATION...FOR MCCARRAN...ISOLATED THUNDERSTORMS AROUND SOUTHERN NEVADA COULD PRODUCE OUTFLOW BOUNDARIES THIS EVENING WITH ABRUPT CHANGES IN WIND DIRECTIONS BUT CONFIDENCE REGARDING ANY PARTICULAR DIRECTION. OTHERWISE...PREVAILING WINDS WILL BE FROM THE SOUTH TO SOUTHWEST THIS EVENING THROUGH THE SATURDAY MORNING. IT COULD BE A DIFFICULT WEEKEND...AS THERE WILL BE INCREASING CHANCES FOR THUNDERSTORMS AROUND SOUTHERN NEVADA SATURDAY AFTERNOON THROUGH SUNDAY WITH THE PRIMARY CONCERNS BEING VERY HEAVY RAIN AND ERRATIC GUSTY WINDS. FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST CALIFORNIA...ISOLATED THUNDERSTORMS AROUND THE REGION WILL GRADUALLY DISSIPATE THIS EVENING. THUNDERSTORM CHANCES WILL INCREASE AREAWIDE SATURDAY AFTERNOON THROUGH SUNDAY...WITH THE MAIN CONCERNS BEING VERY HEAVY RAIN AND ERRATIC GUSTY WINDS. && .SPOTTER INFORMATION STATEMENT...SPOTTER ACTIVATION MAY BE NEEDED OVER THE WEEKEND FOR THUNDERSTORMS WITH VERY HEAVY RAIN AND POTENTIAL FLASH FLOODING. && SHORT TERM/AVIATION...ADAIR LONG TERM...WOLCOTT FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE: HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
The Las Vegas radar (KESX), 134 km away, was scanning. The volume nearest the first event began at 23:30 UTC.
9 flash flood, 2 thunderstorm wind, 1 lightning. Local standard time, as filed.
Thunderstorm winds knocked trees onto power lines.
Eight to ten inches of flowing water, mud, and rocks washed across low spots on several roads.
Water flowed across the intersection of Bank and Armour Streets, and water and small rocks also flowed across Hualapai Mountain Road.
Thunderstorm winds snapped a dozen power poles and took down at least 50 power lines, removed shingles from roofs, ans bent a garage door. 14,200 people lost power.
Lightning struck and damaged a house.
Water and large rocks flowed across Stockton Hill Road near mile marker 8.
Water up to six inches deep flowed down several streets in Lake Havasu City.
Three cars ended up in the wash off Estrella Road, and a total of 13 people were rescued from vehicles around town. At least three people had to wait on top of their cars.
Six inches of water flowed over Bank St. between Airway Ave. and Northern Ave. There was also flooding on Irving St. between Kino Ave. and Gordon Dr.
Water and debris were over the Willow Beach access road.
Temple Bar Access Road was impassable due to flooding from the Detrital Wash.
Kingman Wash Access Road was washed out.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2014Every state in 2014This day in weather historyWarnings in Arizona, August 2014
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: 538714, 538715, 538716, 538717, 538718, 538722, 538725, 538727, 538728, 538729, 538730, 538731.