Another influx of monsoon moisture fueled scattered thunderstorms over northwest Arizona. One storm produced flash flooding.
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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.
Another influx of monsoon moisture fueled scattered thunderstorms over northwest Arizona. One storm produced 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 21, 2:21 PM MST, 3 hours 51 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 221 PM PDT Wed Aug 21 2024 .SYNOPSIS...Two more days of monsoonal activity is expected across northwestern Arizona before a trough of low pressure moves into the intermountain-west and dries out the region. This trough will also help to cool temperatures to below-average readings by this weekend. Meanwhile, gusty southwest winds will pick up Thursday and Friday afternoons, increasing the danger of fires across the southern Great Basin. Unfortunately, the cool-down will be short, and temperatures will rebound back to above-normal levels by early next week. && .SHORT TERM...Through Friday. The combination of a ridge over Texas and a trough dropping into the Pacific Northwest will work together to pull in moist air from northwest Mexico and the Gulf of California. Dewpoints remain close to 60 as far north as Laughlin this afternoon, and PWAT values of 1.25 to 1.5 inches will continue to spread north tonight and Thursday. Isolated thunderstorms are possible over central and southern Mohave County this afternoon and evening, but a better chance for storms will develop overnight and Thursday, mainly over the northern half of Mohave County. Given the increased moisture levels and favorable wind profile that would favor the training of cells, a Flash Flood Watch has been issued for the northern half of Mohave County from late this evening through Thursday evening. Most of the area covered by the watch will see around a half-inch of rain. Still, Isolated amounts of 1.5 to 2 inches will be possible, especially over the higher terrain near Colorado City and Pipe Spring. The moisture will begin to exit the region on Friday resulting in just a slight chance of storms over far eastern areas. The trough mentioned above will continue to move into the intermountain-west by this weekend. Widespread south-to-southwest winds gusting 30 to 40 mph are possible ahead of the trough tomorrow and Friday over southeast California and southern Nevada. These winds, along with the drier conditions further west, will lead to an increased fire risk, mainly across southern Nevada, and a Red Flag Warning has been issued for this area on Thursday and Friday. Friday looks to be the day with the highest potential for gusty winds, and headlines may be needed for that period. The good part about the trough is that temperatures will cool off, with readings falling to just below 100 in the Las Vegas Valley by Friday. .LONG TERM...Saturday through Tuesday. Deep West Coast trough will begin to weaken and swing inland over the weekend, ushering in dry and cooler air to the region. There remains some discrepancy among forecast guidance on finer details of the trough, namely how quickly it weakens and how fast it lifts into the northern Rockies. But regardless, confidence is high that temperatures will drop to their coolest levels since Mid-June. NBM probabilities for a high temperature Saturday of 99 or less are currently near 85 percent, with about a 25 percent chance of being 95 degrees or less. Meanwhile, morning low temperatures in parts of the Owens Valley near Bishop will bottom out in the lower 40s by Sunday morning. The taste of fall won't last long however as ridging will begin to build back across the Southwest early next week, helping to send temperatures back closer to normal by Monday and Tuesday. && .AVIATION...For Harry Reid...Breezy south-southwest winds throughout the TAF period as wind direction stays between 160-240. Speeds generally 10-15 knots with a 90% chance of gusts 20-30 knots during the daytime hours. After 03z, the probability of sustained winds 10+ knots drops below 40% and remains there until 16z tomorrow. FEW-SCT clouds at 10+ kft today, but any afternoon convection remains confined to NW Arizona. For the rest of southern Nevada, northwest Arizona and southeast California...South-southwesterly breezes across the region today, with more westerly winds at KDAG. Speeds this afternoon 10-15 knots with gusts 20-30 knots. Winds at most sites will subside around sunset. Clear skies at KBIH and KDAG, while sites farther east will see FEW-SCT clouds around 10-15kft. Limited potential for convective influence as storms are expected to remain in NW Arizona. KEED and KIFP have the best chance of thunderstorm impacts (rain/wind) today and tonight, but these chances remain below 20%. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && SHORT TERM...Planz LONG TERM...Outler AVIATION...Woods For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
Preliminary Local Storm Report
National Weather Service Las Vegas NV
514 PM PDT Wed Aug 21 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0445 PM Tstm Wnd Gst 6 S Needles 34.77N 114.62W
08/21/2024 M60 MPH San Bernardino CA ASOS
KEED ASOS measured a peak wind gust to 60
mph as thunderstorm approached from the
south. Blowing dust also noted on nearby
webcam.
&&
COPreliminary Local Storm Report
National Weather Service Las Vegas NV
538 PM PDT Wed Aug 21 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0515 PM Tstm Wnd Gst 6 S Needles 34.77N 114.62W
08/21/2024 M61 MPH San Bernardino CA ASOS
KEED ASOS gusted to 61 mph at 515 mph as
another thunderstorm core moved overhead.
&&
COPreliminary Local Storm Report
National Weather Service Las Vegas NV
543 PM PDT Wed Aug 21 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0412 PM Flash Flood 3 SW Valentine 35.36N 113.69W
08/21/2024 Mohave AZ County Official
Mohave County roads reports closure of S
Hackberry Road from HWY 66 to E Main due to
flooding. Nearby Truxton Canyon USGS gage
reports 7 foot water rise within the wash.
&&
COPreliminary Local Storm Report
National Weather Service Las Vegas NV
555 PM PDT Wed Aug 21 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0514 PM Tstm Wnd Gst 6 S Needles 34.77N 114.62W
08/21/2024 M66 MPH San Bernardino CA ASOS
Corrects previous tstm wnd gst report from 6
S Needles. KEED ASOS gusted to 66 mph at 514
mph as another thunderstorm core moved
overhead.
&&
COThe Las Vegas radar (KESX), 115 km away, was scanning. The volume nearest the first event began at 01:14 UTC.
1 flash flood. Local standard time, as filed.
Hackberry Road was closed from Highway 66 to Main Street due to flooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arizona in 2024Every state in 2024This day in weather historyWarnings in Arizona, August 2024
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: 1207877.