A cutoff low moved from the Pacific Ocean through the Desert Southwest, triggering a round of thunderstorms. Some storms produced flash flooding and severe winds.
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.
A cutoff low moved from the Pacific Ocean through the Desert Southwest, triggering a round of thunderstorms. Some storms produced flash flooding and severe winds.
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 Oct 5, 8:45 AM MST, 1 hour 25 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 845 AM PDT Tue Oct 5 2021 .SYNOPSIS...Low pressure moving in from Southern California will spread showers and thunderstorms across areas along and south of Interstate 15 today. Heaviest rainfall and best chances for thunderstorms will be across San Bernardino and Mohave counties. Another weather system will approach the region late in the week with renewed shower chances and increased wind speeds. Temperatures for the remainder of the week will tend to be below average. && .UPDATE...Active start to the day as scattered bands of convection extend from southern Nye/Western Clark county southward towards Lake Havasu. This activity is fueled by marginal instability focused in the 500-700mb layer sampled on this mornings 12z VEF sounding as well as a strongly divergent flow aloft in the northeast quadrant of an approaching low pressure system near San Diego. Overall precipitation amounts thus far have been fairly light, ranging from a tenth or two under most of the heavier downpours, to nearly a half an inch near Jean this morning under some training storm activity. Expecting scattered to numerous thunderstorms to continue through the afternoon hours mainly along and south of I-15 today. Breaks in the cloud cover will encourage stronger destabilization later this morning, and when combined with cold mid level temperatures of -13 to -15C at 500mb, small hail will be possible with stronger updrafts. Will be making some minor tweaks to the current forecast to account for latest trends, but overall things remain on track. -Outler- && .SHORT TERM...Today through Wednesday night. A line of showers was developing from near Baker up over Las Vegas early this morning under the diffluent northeast quadrant of the closed upper low centered along the SoCal Coast. The circulation center will open up and lift across far southeast California into western Arizona this afternoon and evening leading to scattered to numerous rain showers and the potential for thunderstorms. The latest NBM and HREF solutions continue to indicated Mohave County will see the highest concentration of showers and thunderstorms, though nearby areas of eastern Clark and San Bernardino counties will also be favored, but to a lesser extent. The latest QPF estimates still indicate 0.25-0.50" over central and eastern Mohave counties and generally 0.10" or less over Clark and eastern San Bernardino counties with amounts of 0.25-0.33" in the Spring Mountains. Of course, the convective nature of the rainfall will lead to isolated higher amounts. Also, some small hail will be possible with thunderstorms...especially under the cold pool tracking over central and southern Mohave county. Temperatures will be around 10 degrees cooler today than Monday. Showers and thunderstorms will continue through early evening then should dissipate by midnight. A drying southwest flow will develop over our region as the trough lifts away leaving partly cloudy skies and temperatures only climbing 2-3 degrees. Highs will be a few degrees below normal with readings in the 80s across most of the Mojave Desert zones. .LONG TERM...Thursday through Tuesday. Progressive, more fall-like pattern illustrated by ensemble guidance will take us into next week. Next upstream trough coming out of the Gulf of Alaska progged to split with southern stream energy digging down the California Coast Thursday before turning inland across southern California/Mojave Desert Friday. Expect increasing winds along with another round of light showers. This system is colder and may bring the first snowflakes to the higher elevations of the southern Sierra. Additional energy coming down backside of trough will keep it cool into Saturday with light showers possible over the higher terrain. Even deeper trough possible early next week. Jury still out on just how far south this trough may dig and just how wet it might be. Right now, system looks to take a more inland trajectory which would lead to a drier system. More confident that it will become breezy and colder by the middle of next week. && .AVIATION...For McCarran...Winds will follow diurnal patterns this morning before becoming more south or southeast this afternoon. Speeds should remain at 8KT or less through the period. An area of low pressure will move into the region through the day bringing isolated showers through early afternoon with the better chances of seeing shower activity at the airport between 20z-00z this afternoon. Cigs may lower to around 8k feet with any showers, but there is also some potential of cigs dropping to around 6k feet with any heavier shower activity. Isolated thunderstorms are also possible this afternoon, but confidence is too low at this time to include TS in the TAFs. Precipitation is expected to end this evening, with conditions improving overnight. For the rest of southern Nevada, northwest Arizona and southeast California...Clouds will continue to increase and lower this morning as an area of low pressure moves into the region. Isolated to scattered showers and afternoon thunderstorms will be possible over much of the area, with the exception of KBIH where no shower activity is expected. Ceilings to around 8000ft and mountain obscuration will be possible with any showers, and lower ceilings down to 5000ft, small hail, and moderate rain would be possible with any thunderstorm. Conditions will improve this evening and overnight as rain ends from southwest to northeast. No significant winds are expected with most areas seeing wind speeds less than 10 kts, however, there is some potential of seeing wind gusts to around 20 kts near any thunderstorms. && .SPOTTER INFORMATION STATEMENT...Showers and thunderstorms are likely to impact areas mainly along and south of I-15 today. Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && SHORT TERM...Adair LONG TERM...Pierce AVIATION...Gorelow 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
920 AM PDT TUE OCT 5 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0300 AM TSTM WND DMG 1 SSE YUCCA VALLEY 34.10N 116.43W
10/05/2021 SAN BERNARDINO CA PUBLIC
LARGE TREE DOWN IN YUCCA VALLEY DUE TO
THUNDERSTORM RELATED WINDS. PUBLIC ESTIMATED
A TIME OF 3AM WHICH HAS BEEN CONFIRMED VIA
RADAR.
&&
VARIANThe Las Vegas radar (KESX), 168 km away, was scanning. The volume nearest the first event began at 17:10 UTC.
5 flash flood, 4 thunderstorm wind. Local standard time, as filed.
Banegas Ranch Road was closed from Banegas Ranch to Highway 93 due to flooding.
Signal Road was closed from Alamo Road to Highway 93 due to flooding.
Bogeles Ranch Road was closed from Upper Trout Creek Road to Bogeles Ranch due to flooding.
Pump Station Road and Huffritter Road were closed from Back Road to Highway 93 due to flooding.
Hackberry Road was closed from Highway 93 to Route 66 due to flooding.
Thunderstorm winds knocked down multiple heavy-duty command tents and porta-potties.
Thunderstorm winds blew down trees and power lines across the city of Kingman.
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, October 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: 989145, 989146, 989147, 989148, 989149, 989150, 989151, 989152, 989153.