An upper level low dove south through California and then moved slowly across the Desert Southwest. Ahead of the low, strong south to southwest winds occurred; later, thunderstorms developed under the low center.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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.
An upper level low dove south through California and then moved slowly across the Desert Southwest. Ahead of the low, strong south to southwest winds occurred; later, thunderstorms developed under the low center.
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 May 6, 9:39 AM PST, 1 hour 51 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 1039 AM PDT Sat May 6 2017 .SYNOPSIS...A low pressure system will be impacting the region through the weekend bringing cooler temperatures and breezy to gusty winds along with shower and thunderstorm chances. && .UPDATE...Another update to issue Winter Weather Advisories for the Sierra and White Mountains (today through Monday afternoon), and Spring Mountains (today through Sunday morning). This is in response to increasing chances for showers/thunderstorms that could lower snow levels this afternoon followed by rapidly lowering snow levels tonight. The threat for the Spring Mountains should taper off tomorrow morning as that area falls within a dry slot. However chances for one or two decent rounds of precipitation will remain possible across Inyo county into Monday. Sky/PoP/Wx/QPF grids have all been updated into Monday. While snow totals may not technically reach advisory levels (and will generally by highly variable), the decision was made based on the recent warm spell and the likelihood of outdoor enthusiasts enjoying the mountain wilderness this weekend. They may be caught off-guard by sudden winter weather conditions such as heavy snow in addition to lightning, hail, and gusty winds. && .PREV UPDATE.../issued at 826 AM PDT Sat May 6 2017/ Quick update this morning to make some tweaks to the PoP/Wx/QPF and Wind grids through tonight to better account for the latest high-res guidance. Main changes were to expand PoPs during each period and to increase overall QPF. The overall trends discussed in the previous short term discussion still hold. Showers/thunderstorm development is expected to begin around noon today over the Spring Mountains north across the NNSS. Development may begin 1-2 hours earlier over the Sierra. I expanded precip chances south to the Mojave National Preserve today and we will be watching closely for any development that could move into Las Vegas. Chances for showers in the valley today look slim, and mainly limited to its fringes. Better chances will develop overnight especially between 10pm and 5am. A few inches of snow are possible overnight in the Spring Mountains above 8000 feet. Focus then turns to Sunday when a plume of wrap-around moisture is expected to impact the Sierra. I'll be taking a close look and the need for winter headlines. && .PREV DISCUSSION... /issued at 252 AM PDT Sat May 6 2017/ .SHORT TERM...through Sunday night. The focus of the short term continues to be a Pacific trough that is forecast to cut off and remain over the area for at least the next few days. Gusty winds, rain, thunderstorms, and even a little mountain snow will be the primary hazards. Incoming trough currently digging down along the west coast seen easily on water vapor imagery this morning, and is still forecast to begin cutting off today. Microwave satellite imagery indicates no significant moisture plume yet, with tropical moisture remaining south of 20N. The next 12 hours or so should give a pretty good indication on whether the trough will continue shunting moisture or begin to ingest more moisture as it closes. Even with the modest moisture available, forcing for ascent should not be an issue, and with cold temps aloft, ample ingredients in place for shower and thunderstorm activity. Models in decent agreement on the best window for activity late Saturday night into Sunday morning as shortwave energy rotates through cutoff upper low. Instability will likely be ample to begin generating showers and thunderstorms as early as this afternoon, mainly from the Colorado River valley and northwestward. As temperatures aloft cool, would not be surprised to see some small hail from the more rigorous updrafts and a quick inch or two of snow above 8000 feet or so. Winds could prove a bit tricky with this system, with parameters not lining up real well. Orientation of the trough as it digs, cuts off, and begins its inland trek today keep thermal gradients W-E with the minima approaching overhead tonight. Additionally, most momentum associated with the upper-level low remain on the south and west sides of the low - not over the area. Nonetheless, hard to rule out advisory level gusts across much of the area this afternoon, with widespread gusty winds still expected. .LONG TERM...Monday through Friday. The cutoff low and its assortment of weather will be the main focus for the first half of this period. Models are tightly clustered, and also agree well with previous runs, so confidence in the large scale pattern is above average, but confidence in details such as precip placement and point temperatures is below average. On Monday, the low has dived well south of the area, with models indicating a significant dry slot over most of our CWA between higher precip chances near the low center and also in a SW-NE oriented band from the Sierra through the Great Basin. Tuesday, as the low tracks northeast across Arizona, models suggest the northern band will fall apart and precip chances will consolidate in the western semicircle of the low. Raised PoPs for our eastern zones, particularly Mohave County, for this period. As the low pulls away to the east Wednesday, precip chances will decrease from west to east, with dry weather expected areawide from Wednesday night through Friday. Temperatures are expected to increase overall from the abnormally chilly day on Sunday, but as noted earlier, confidence in point temperatures is low because of dependence on exact placement of cloud cover and precip/virga. As the area dries out and skies clear up Thursday and Friday, temps should return to near normal. && .FIRE WEATHER...A deep area of low pressure will approach the region today, bringing gusty winds to much of the area. Low relative humidity along with the gusty winds will create critical fire weather for northwest Arizona and the Colorado River Valley, where Red Flag Warnings have been posted. Expect calmer, cooler, and more moist conditions as the low pressure system lingers over the region into early next week. && .AVIATION...For McCarran...Gusty south winds will continue to increase through the afternoon before becoming more variable as speeds decrease tonight. Shower and thunderstorm chances increasing through the afternoon for the Beatty corridor, spreading into the valley overnight. Turbulence, both clear-air and associated with shower/thunderstorm activity as well as icing hazards expected through the period. For the rest of southern Nevada, northwest Arizona and southeast California...Breezy to gusty southerly winds expected across the region through the weekend, strongest on Saturday. Shower and thunderstorm chances begin to increase this afternoon and last through the remainder of the period. Turbulence, both clear-air and associated with shower/thunderstorm activity as well as icing hazards expected through the period. && .SPOTTER INFORMATION STATEMENT...An area of low pressure will impact the region through the weekend, bringing showers, thunderstorms, and gusty winds. Spotters are encouraged to report any impacts from the wind, such as damage or blowing dust/visibility restrictions as well as rain amounts according to standard operating procedures. && Update................Wolcott Short Term/Aviation...Steele Long Term.............Morgan 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), 58 km away, was scanning. The volume nearest the first event began at 02:46 UTC.
2 strong wind, 1 thunderstorm wind. Local standard time, as filed.
Strong winds downed a power pole and a tree branch.
Strong winds tossed several canopy tents at a carnival in Mesquite, injuring two people.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Nevada in 2017Every state in 2017This day in weather historyWarnings in Nevada, May 2017
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: 692271, 692272, 692274.