Monsoon moisture fueled thunderstorms over the Mojave Desert, many of which produced severe winds and flash flooding.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 thunderstorms over the Mojave Desert, many of which produced severe winds 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 10, 1:48 PM MST, 54 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 148 PM PDT Tue Aug 10 2021 .SYNOPSIS...Thunderstorm chances southeast of Interstate 15 will end late this evening, with another round spreading to much of the region Wednesday. After a lull Thursday through Saturday, thunderstorm chances are expected to ramp up Sunday into early next week. The main impacts for the upcoming active period will be flash flooding, especially in the higher terrain, and gusty outflow winds. && .SHORT TERM...through Wednesday night. Early afternoon satellite and radar loop showed scattered thunderstorms over Mohave county and isolated storms over southern Clark and far eastern San Bernardino counties. Farther north and west, shallower cumulus had developed over Lincoln and Nye counties, the Spring Mountains and Sheep Range in Clark county, and the Morongo Basin in San Bernardino county. A cluster of storms north of Kingman looked like it was developing an organized cold pool, which was beginning to accelerate southwest. This scenario was advertised in many of the convective allowing high resolution models earlier, with the usual disagreements on location and timing. Based on how things are evolving, there are two most likely scenarios: the storms track south-southwest all the way to Lake Havasu City this evening, or they weaken and break apart when they hit an area which was stabilized by an earlier storm over the Hualapai Mountains. The forecast represents a middle ground between these two scenarios, with low-end chance PoPs tracking all the way to our southern CWA border this evening. After a lull overnight into the morning, storms will fire again Wednesday afternoon, with the most likely areas being Mohave county and the higher terrain of San Bernardino, Clark, and Inyo counties. As was the case yesterday, it looks like there could be isolated flash flooding in any of these areas, but no one area is strongly favored for widespread flooding. Thus, have again forgone any Flash Flood Watches, but this shouldn't be interpreted as meaning that the risk is zero. .LONG TERM...Thursday through Tuesday. Monsoonal moisture lingers over the region for the later half of the workweek though we will be in between any larger scale forcing mechanisms moving through. This will tend to limit the best shower and thunderstorm chances to mainly the higher terrain portions of the forecast area, and particularly northwest Arizona. However, over the weekend, another inverted trough moves into Arizona and eventually lifts north, which may bring another round of more active convection to the area Sunday into early next week. However, there remains some variability in the strength of this wave, and possible larger scale troughing that may influence the region next week. So uncertainty in the details remains fairly high, but NBM generated PoPs do advertise a marked increase in PoPs Sunday-Tuesday, which seems reasonable. && .AVIATION...For McCarran...Gusty southeasterly wind will continue through the evening hours. There is a possibility of a wind shift due to outflow from storms in southern Clark County or Mohave County this afternoon and evening but confidence is low. Overnight, wind will decrease and become more southerly, exhibiting a more typical diurnal trend through the morning hours. During this period, CIGS of 12-15kft are likely. There is an increased chance for thunderstorms during the afternoon hours. For the rest of southern Nevada, northwest Arizona and southeast California...South to southeasterly gusty wind can be expected at most terminals this evening with thunderstorms around the Colorado River Valley potentially affecting winds around KEED and KIFP. CIGS aoa 12kft can be expected except in areas of thunderstorms where lower CIGS to 8kft can be expected. Expect a return to typical diurnal trends overnight. Isolated to scattered thunderstorms can be expected in most areas Wednesday as well. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && SHORT TERM...Morgan LONG TERM...Outler AVIATION...Berc For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
The Las Vegas radar (KESX), 69 km away, was scanning. The volume nearest the first event began at 21:38 UTC.
10 flash flood, 2 dust storm, 2 thunderstorm wind. Local standard time, as filed.
Pierce Ferry Road was closed from mile marker 13 to Antares Road due to flooding.
Dust storm conditions halted traffic on Stockton Hill Road at mile marker 26.
Antares Road was closed from Route 66 to Pierce Ferry Road due to flooding.
The intersection of Morrow and Burbank was flooded.
Eight inches of water flowed over Bank Street just north of the high school.
Bogeles Ranch Road was closed from Upper Trout Creek Road due to flooding.
Huffritter Road was closed from Highway 93 to Back Road due to flooding.
Pump Station Road was closed from Highway 93 to Back Road due to flooding.
Shingles were blown off homes near Palo Verde and Avalon and near Alpine and Havasupai. Several large trees were downed near Smoketree and McCulloch.
Dust storm conditions reduced visibility to less than a quarter mile near Desert Hills.
Oatman Highway was closed from Ramada Road to Cool Springs due to flooding.
Richard Street was closed for five to ten minutes due to flooding of Short Creek.
Hackberry Road was closed from Main Street to Route 66 due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2021Every state in 2021This day in weather historyWarnings in Arizona, August 2021
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: 981243, 981244, 981246, 981247, 981248, 981252, 981253, 981254, 981255, 981256, 981257, 981267, 981277, 981278.