A strong Pacific low pressure system plus leftover moisture from the remnants of Hurricane Rosa produced thunderstorms over the Mojave Desert and southern Great Basin. Some storms 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.
A strong Pacific low pressure system plus leftover moisture from the remnants of Hurricane Rosa produced thunderstorms over the Mojave Desert and southern Great Basin. Some storms 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 Oct 3, 9:33 AM PST, 1 hour 42 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 1033 AM PDT Wed Oct 3 2018 .SYNOPSIS...Scattered showers and thunderstorms are expected through the afternoon, with isolated heavy rainfall possible. An approaching Pacific storm system will increase thunderstorm coverage this evening, especially over Mohave County and adjacent areas of Clark and Lincoln counties, where severe storms will be possible. Cooler storm systems coming in from the north will bring unsettled conditions with below normal temperatures over the weekend into early next week. && .UPDATE...Isolated thunderstorms were already firing this morning over southeast Lincoln/northeast Clark counties. Lines of convection were oriented from south to north and could be seen on satellite loops becoming more enhanced. The upper low off the California Coast will finally move inland over the next 12 hours and increasing upward forcing and wind shear along the leading edge will produce organized bands of thunderstorms especially across substantial portions of southern Nevada and northwest Arizona...especially after sunset through the overnight hours. Isolated severe thunderstorms will be possible and the best threat areas will be over Lincoln, northeast Clark and Mohave County. Since conditions for organized thunderstorms will come together primarily after dark...storms will not be quite as strong as they otherwise would with the aid of daytime heating. Minor changes will be made to the PoP/WX/QPF grids based on 12Z model input, but the going forecast detailed in the previous discussion appear to be on track. && .PREV DISCUSSION...232 AM PDT .DISCUSSION...through Saturday night. Satellite and area radars showed isolated showers and thunderstorms bubbling early this morning in an arc from near Tonopah across Lincoln County and southward into northern Mohave County. This general area should be favored for more development this morning, then chances start to increase across the western zones as the Pacific low off Point Conception finally opens up and swings inland. This low will take on a negative tilt as it comes inland this evening, enhancing difluence and deep layer shear ahead of it. This will act on moderately unstable air to kick off possibly severe thunderstorms late this evening. The high resolution models are targeting Mohave County for the brunt of it, with perhaps a secondary max in Lincoln County and a few storms in far eastern Clark County. Previous forecast had this idea pretty well in hand, and made only minor tweaks. Precip chances will decrease from southwest to northeast tonight as the low moves through. Leftover showers Thursday morning will increase in the afternoon and evening across the southern Great Basin as a northern stream shortwave trough passes through, leaving dry weather in its wake Friday afternoon. This will be short lived however, as another northern stream trough digs in and amplifies over our area Saturday, with shower chances increasing from north to south as the day goes on. Since these two waves will be coming from the Gulf of Alaska, they will bring more chilly air, keeping temperatures below normal over the weekend. && .AVIATION...For McCarran...Southerly winds will prevail for the upcoming TAF period. Speeds will remain between 8-11 knots for much of the morning before gusts become more prevalent during the afternoon with speeds up to around 20 knots through this evening. Isolated thunderstorms will be possible this afternoon and evening in the vicinity of the terminal. Storms lingering into the overnight period cannot be ruled out but confidence is not high in location or timing so there is currently no mention of storms after 03z Thursday. A scattered cloud deck around 8k feet will be possible once again today; lowering with any showers or storms that directly affect the terminal. Tonight southwest around 10 knots will be likely. For the rest of southern Nevada, northwest Arizona and southeast California...South to southwest winds will prevail for the period; becoming gusty during the afternoon and early evening. Speeds should remain between 10-15 knots gusting 20-25 knots. Scattered storms will be possible again today across most areas. The highest coverage will be during the afternoon and evening across Lincoln, Mohave, Clark, and northern Inyo counties. Potential exists for isolated, strong storms lingering into the overnight hours across southern Nevada and northwest Arizona but confidence is low in specifics at this time. Cigs between 6k-8k feet will be likely today; lowering with any showers or storm activity. Gusts should become intermittent after sundown. && .SPOTTER INFORMATION STATEMENT...Severe thunderstorms will be possible Wednesday evening, especially in Mohave County and nearby areas of Clark and Lincoln counties. Isolated flash flooding will also be possible. We encourage spotters to report any significant weather or impacts in your area. && UPDATE...Adair DISCUSSION...Morgan AVIATION...Guillet For more forecast information...see us on our webpage: http://weather.gov/lasvegas or follow us on Facebook and Twitter
The Cedar City radar (KICX), 145 km away, was scanning. The volume nearest the first event began at 19:13 UTC.
1 flash flood, 1 thunderstorm wind. Local standard time, as filed.
Flash flooding on Main Street in Pioche left water and debris in the street and water in several buildings.
Two sensors measured wind gusts to 60 and 58 mph.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2018Every state in 2018This day in weather historyWarnings in Nevada, October 2018
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: 780106, 780107.