High heat and a little mid level moisture triggered isolated thunderstorms over the Mojave Desert. A few storms produced high winds in the deserts and flash flooding in the mountains.
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.
High heat and a little mid level moisture triggered isolated thunderstorms over the Mojave Desert. A few storms produced high winds in the deserts and flash flooding in the mountains.
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 31, 8:30 PM PST, 56 minutes earlier.
Area Forecast Discussion National Weather Service Las Vegas NV 930 PM PDT Thu Aug 31 2017 .SYNOPSIS...Scattered showers and thunderstorms will continue each afternoon into the weekend with temperatures remaining above normal. There is a chance that storm activity will increase late this weekend or early next week as moisture from Tropical Storm Lidia approaches the region. && .UPDATE...Consolidating convection heading south through Inyo County as expected this evening. Some decent winds and localized moderate rain recorded. More convection developed around the Spring Mountains which is sending strong outflow into the Las Vegas Valley. Gusts 40 to 50 mph will be common for a little while before 1030 pm at least in the north half of the valley. Some other weak convection around the CWA and most activity expected to drop off during the overnight hours. No updates planned this evening. && .AVIATION...For McCarran...Strong northwesterly outflow winds gusting around 30 knots likely by 05z through about 06z then lighter northwest winds. Chances for shower/thunderstorm activity tonight over the terminal are low, however the Beatty and Daggett corridors may see scattered shower activity. As showers diminishes winds should become light overnight and variable through early Friday. Skies will be scattered to broken between 12-15kft. Diurnal winds expected Friday, with chances for afternoon thunderstorms over the mountains. For the rest of southern Nevada, northwest Arizona and southeast California...Scattered showers and thunderstorms expected to develop this afternoon and evening in areas north of Interstate 15. Storms will likely produce gusty and erratic outflows. The exception will be KDAG, where a chance for showers will be possible this evening. Outside of outflow boundary influence, typical diurnal winds will set up tonight in areas south of Interstate 15. Skies will be scattered to broken between 12-15kft. && .PREV DISCUSSION... 241 PM PDT Thu Aug 31 2017 .SHORT TERM...Through Sunday Night. A bit of a slow start to the convection this afternoon as expected. Thus far storms were beginning to develop over the Mojave Preserve, NNSS, and southern Sierra. Fairly widespread instability of 500-100 J/kg and isolated areas of around 1500 J/kg and low to moderate grade monsoon moisture has created an environment favorable for additional thunderstorm activity through the afternoon. Lift is being provided courtesy a 50kt jet streak extending from southwest to northeast across the region as well as diurnal heating over the higher terrain. Expect storm activity to continue to develop this afternoon over the higher terrain across southern Great Basin and Mojave Desert then begin to congeal into an area of showers and embedded storms over Inyo, Nye, and western San Bernardino counties this evening/overnight. Storms that do form will have the potential for isolated severe wind gusts thanks to a relatively dry sub-cloud layer as noted by inverted-V forecast soundings. Activity is expected to be much more isolated on Friday, with chances limited to mainly the higher elevations of the far southern Great Basin and northern Mojave Desert. Attention then turns to Tropical Storm Lidia south near the tip of Baja California. It's track is still very uncertain. As is the trajectory of it's remnant moisture by the weekend. Guidance remains at odds as just how far north and east moisture will push. The most aggressive solutions (GFS-based) take a decent swath of its moisture north into our neck of the woods, while others take the storm and it's moisture out to sea. As with any tropical influence, if that moisture does in fact make it this far north, it will bring with it a significantly increased chance of warm rain processes leading to possible flash flooding. We will continue to monitor the situation and update the forecast as needed. .LONG TERM...Monday through Wednesday. Strong ridging and remnant moisture from tropical storm Lidia will be the focus through the first half of next week. Current GOES water vapor imagery shows a strong upper ridge pushing into the Pacific Northwest. Meanwhile, tropical storm (TS) Lidia sits at the southern tip of Baja California. Current track forecast of TS Lidia indicates a westward pivot Sunday as a result of a strong upper high building into the southwest. Although Lidia is not expected to impact the forecast area directly, GFS and ECMWF solutions indicate remnant moisture being advected into our area. On Monday the highest-grade moisture looks to be focused central and southeast California with decent moisture in remaining areas. Thunderstorm activity on Monday will significantly depend on how much moisture is drawn from TS Lidia. After Monday, moisture become trapped beneath the upper-level anticyclone which should center around southeast Utah. Given decent mid-level moisture and daytime heating, conditions should favor thunderstorms over higher terrain each afternoon. Under the high pressure temperatures will remain elevated, around 4 to 6 degrees above normal. && .SPOTTER INFORMATION STATEMENT...Scattered showers and thunderstorms will continue each afternoon into the weekend with a possible uptick late weekend or early next week. Spotters are encouraged to report significant weather or impacts according to standard operating procedures. && UPDATE/AVIATION...Harrison SHORT TERM............Wolcott LONG TERM....Boothe For more forecast information...see us on our webpage: http://weather.gov/lasvegas or follow us on Facebook and Twitter
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LAS VEGAS NV
815 PM PDT THU AUG 31 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0700 PM TSTM WND GST 24 N MERCURY 37.00N 116.06W
08/31/2017 M58 MPH NYE NV MESONET
MEASURED AT REBOUND MEDA (SOUTH) MESONET
STATION.
&&
JHThe Edwards AFB radar (KEYX), 92 km away, was scanning. The volume nearest the first event began at 05:24 UTC.
1 thunderstorm wind. Local standard time, as filed.
Severe thunderstorm outflow winds persisted for over two and a half hours.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, August 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: 715683.