Thunderstorms with very impressive supercellular structures and radar presentations (unusual for the region) produced large hail, damaging winds, 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.
Thunderstorms with very impressive supercellular structures and radar presentations (unusual for the region) produced large hail, damaging 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 Sep 23, 8:42 AM MST, 4 hours 1 minute earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 842 AM PDT Mon Sep 23 2019 .SYNOPSIS...A vigorous low pressure system dropping into southern Nevada today will bring increasing chances for showers and thunderstorms today especially over northwest Arizona where extensive heavy rainfall and flash flooding are possible this afternoon and tonight. The low pressure system will park near Yuma Arizona the next few days then lift away as a deep broad area of low pressure develops over the western states this weekend leading to widespread gusty winds and a significant cooling trend. && .UPDATE...Ingredients coming together rapidly for a rather active day in Arizona. Moisture currently working its way northward, with surface dewpoints and PWATs rising rapidly in southern Mohave county. Wind shear, moisture, and steepening lapse rates will support strong to severe thunderstorms in southern Mohave county. Flooding is possible with training of storms. The best chances look to be roughly south of Kingman, but recent high-res trends show secondary activity popping up around Boulder City and Lake Mead this evening - with the Las Vegas valley on the fringe, but not out of the woods. && .DISCUSSION...Today through next Monday. An active weather pattern is shaping up today which will provide thunderstorms over northwest Arizona with the potential for heavy rain. Isolated large hail and damaging winds possible with a few storms. A Flash Flood Watch has been issued for central and southern Mohave County from 11 AM this morning through late tonight. Nearby areas of far southern Nevada and southeast California will see isolated thunderstorms, but the primary focus will be in northwest Arizona. The evolving scenario includes fairly deep moisture that has been slowly moving up from northwest Mexico and will be pulled up fairly quickly over the southern half of Mohave County this morning ahead of a vigorous closed low that will spin directly into southern Nevada by this afternoon and then over Yuma Arizona late tonight. The cyclogenesis associated with the closed low will provide both dynamic upward forcing and increasing wind shear to support training and organized storms over central and southern Mohave County from late this morning through late this evening. As the closed low center moves down the Colorado River Valley toward Yuma tonight, storms may develop under the cold pool then pull south of Lake Havasu after midnight. The cutoff low is now forecast to remain quasi-stationary around Yuma through Wednesday then slowly lift toward Kingman Thursday which will increase the chances of another round of showers and thunderstorms Wednesday into Thursday. The ensemble models indicate the broad upstream trough over the northwest states will finally dig and encompass the entire western states Friday through next weekend which will produce breezy and progressively cooler conditions through the weekend and early next week with temperatures trending well below normal. && .AVIATION...For McCarran...Light, south to southwest winds beneath a periods of scattered to broken at or above 20 kft will continue through 18z. Winds will stay southerly as they increase this afternoon, with gusts reaching 25 knots at times. The late afternoon and evening forecast will be tricky. A cold front is expected to push 10-12 kt northwest winds, scattered clouds at or above 10 kft, and vicinity showers into the valley between 01-04z. Meanwhile, easterly outflow may be possible in the same general timeframe, which may override the frontal winds. That said, forecast confidence this evening is low. Expect variable winds overnight tonight, favoring a northwest to west direction and lingering scattered mid- level clouds. For the rest of southern Nevada, northwest Arizona and southeast California...Light winds will give way to 10-15 kt south to southwest winds at each TAF site with the exception of KBIH. A cold front will usher in north winds this afternoon at KBIH and advance further south into southern Nevada and southeast California this evening. T-storms will focus across the lower Colorado river and NW Arizona areas today; starting as early as 16z. CIGs dropping to 5-7 kft, strong winds and hail will be possible with some storms; storm activity will wane around 03-06z. While storms will be generally confined to NW Arizona, showers will be possible anywhere south of I- 15. Generally, north winds around 7-12 kts along with scattered CIGs at or above 10kft are expected overnight. && .SPOTTER INFORMATION STATEMENT...A Flash Flood Watch is in effect for central and southern Mohave County Arizona from 11 AM MST this morning until late tonight. Spotter activation for Mohave County is likely. Elsewhere in nearby southern Nevada and southeast California, spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && UPDATE.......Steele DISCUSSION...Adair AVIATION.....Boothe 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), 136 km away, was scanning. The volume nearest the first event began at 19:44 UTC.
4 hail, 4 flash flood, 1 thunderstorm wind. Local standard time, as filed.
A spotter estimated one inch hail near the Lake Havasu City airport.
A video of golf ball size hail falling was posted to social media.
Boundary Cone Road was heavily damaged by flooding and closed.
Thunderstorm winds blew down a power pole near Boundary Cone Road and Mountain View Road, knocking out power to 3700 customers.
Willow Drive was flooded east of Willow Valley.
Archibald Wash flooded Pierce Ferry Road and Stockton Hill Road with water and debris.
Oatman-Topock Highway was flooded and closed from mile marker 0 to Boundary Cone Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2019Every state in 2019This day in weather historyWarnings in Arizona, September 2019
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: 857355, 857356, 857357, 857360, 857361, 857362, 857366, 857368, 857371.