Upper level moisture which sheared off from former Pacific Hurricane Jova fueled isolated thunderstorms in the southern Great Basin. One produced 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.
Upper level moisture which sheared off from former Pacific Hurricane Jova fueled isolated thunderstorms in the southern Great Basin. One produced 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 12, 11:18 AM PST, 7 hours 12 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 1218 PM PDT Tue Sep 12 2023 .SYNOPSIS...Another round of thunderstorms is likely this afternoon and evening, mainly in northwest Arizona and southern Nevada. The main concern is heavy rainfall, along with strong winds and frequent lightning. Additional storm activity will taper off the next two days, becoming dry by the weekend. && .DISCUSSION...Through Next Wednesday. Skies have started to clear out over southern Nevada and northwest Arizona, meaning a transition from stratiform rainfall to potential convective development. Activity should peak between 20Z and 02Z, though isolated storms have already started to form over mountains in southern Nevada. Slow clearing of cloud cover over Mohave County and as a result cooler temperatures over the area may somewhat delay convective initiation. Once storms do start to develop, the presence of 35 knots of surface to 6 km shear and around 1000 J/kg MLCAPE may allow for the development of small hail and frequent lightning. Afternoon DCAPE values between 1100 and 1400 J/kg mean that gusty outflow winds are a threat as well. PWATs between 1.0 and 1.4 inches could lead to locally heavy rainfall, as seen in some storms so far this morning. Convection seen so far this morning has also mostly been terrain driven, a pattern expected to continue into the afternoon. Tomorrow, a ridge of high pressure over the eastern Pacific Ocean and zonal flow over the Four Corners states will create northwesterly flow aloft over the forecast area. Shortwaves moving along this pattern and lingering moisture may lead to additional isolated thunderstorms on Wednesday and Thursday afternoon. The ridge of high pressure moves in from the Pacific into the western United States towards the end of the week, creating dry and stable conditions over the forecast area Friday and through the weekend. Long range models are starting to show agreement that low pressure will move into the Intermountain West sometime in the middle of next week, but details are unclear at this time. Will continue to monitor the development of this feature. Temperatures rise slightly as high pressure builds in, with highs staying within a few degrees of average. Temperatures begin to fall back to below average values as the trough starts to influence the upper level pattern above the forecast area. && .AVIATION...For Harry Reid...A complex aviation forecast period is expected with scattered showers and storms from 20z today through 02z Wednesday. While confidence is low in the terminal being directly impacted, at least vicinity thunder is warranted. Gusty winds and heavy rains to accompany any storm, which would naturally result in sub VFR conditions. Otherwise winds to shift from south/southeast through the afternoon, to west in the evening. Wind speeds to remain 10 knots or less outside of thunderstorms. For the rest of southern Nevada, northwest Arizona and southeast California...Showers and thunderstorms to affect eastern terminals, including KVGT/KHND and KIFP. Activity looks to peak between 20z and 02z. Gusty winds and heavy rainfall to accompany any storm. While confidence is not sufficiently high for prevailing thunder, several terminals carry vicinity thunder for several hours. Winds to largely remain diurnally driven from the south/southwest. KBIH will be the exception with east/southeast winds through the day, shifting to the northwest late tonight. Aside from any local thunderstorm impacts, VFR visibilities and ceilings can be expected. && .SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report any significant weather or impacts according to standard operating procedures. && DISCUSSION...Meltzer AVIATION...Austin For more forecast information...see us on our webpage: https://weather.gov/lasvegas or follow us on Facebook and Twitter
The national radar mosaic for the moment the first event began.
1 flood. Local standard time, as filed.
Flooding of the Meadow Valley Wash deposited debris on roads in Eagle Valley. No road closures were needed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2023Every state in 2023This day in weather historyWarnings in Nevada, September 2023
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: 1141951.