Flash Flood Warning 25, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
436 PM PDT Wed Aug 12 2026

.KEY MESSAGES...

* This afternoon offers widespread chances for storms with an
  increased risk for flooding in Mohave County AZ, with a Flash
  Flood Watch issued from noon through midnight.

* Daily afternoon to evening isolated thunderstorm chances will
  continue through the late week, with the greatest chances over
  higher terrain and some storms spreading into adjacent valleys.

&&

.DISCUSSION...Through Tuesday.

Today is shaping up to be one of the most active monsoon days of
the season thus far. Latest SPC mesoanalysis shows the 1" PWAT
contour extending all the way up into the southern Great Basin.
With mostly sunny skies west of the Colorado River and a subtle
trough approaching off the Pacific, all the ingredients are there
for scattered storms across the area. Main concerns will be flash
flooding and gusty outflow winds. Morning convection in central
Mohave County produced impressive rain rates/totals, but will
likely limit (or at least delay) additional activity in this area
as the atmosphere has been worked over. This could set up an
instability gradient for afternoon storms to run along, pushing
them down the lower Colorado River Valley. SPC has highlighted
this area with a marginal risk of severe winds. Activity may
linger in the southern Great Basin and lower Colorado River Valley
this evening, but things should largely be on the downtrend
around sunset.

Tomorrow, the trough moves a bit closer and flow aloft
strengthens. This will speed up storm movement, reducing the
risk of flash flooding outside of training storms. However, this
stronger flow aloft will also produce an uptick in vertical wind
shear, potentially allowing for more organized convection. This
signal is most clear in the southern Great Basin where the latest
HREF indicates 70-90% probabilities of 30+ knot thunderstorm winds
and a 10-20% chance of 50+ knots. Wouldn't rule out the potential
for hail as well thanks to modestly rotating updrafts depicted in
some CAMs. Storm coverage across the Mojave Desert should be more
isolated in nature on Thursday. On Friday, the southwesterly flow
pushes moisture mainly into southeastern NV and northwestern AZ,
where isolated to scattered convection is yet again possible in
the afternoon hours. Drier conditions with just isolated activity
possible over the weekend.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...The
initial round of thunderstorms has pushed to the east. There is
still a 30% probability of additional showers and thunderstorms
during the evening hours. Thunderstorms at the terminals could
result in brief heavy rain, visibility under 5SM, sudden gusty
winds, and CIGs below 8000ft. Easterly winds will become southerly
after sunset and then become light and variable overnight. VFR
conditions with SCT-BKN clouds over 10kft are expected overnight.
Southerly winds will develop on Thursday afternoon with gusts to
around 25 kts. There is a 20-30% chance of thunderstorms on Thursday
afternoon with brief heavy rain, sudden gusts winds and CIGs below
8000 feet.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Scattered showers and
thunderstorms will continue through at least sunset. Any storms
could produce lightning, heavy rain, sudden gusty winds, and CIGs
below 8000ft. Outside of convective influences, south to southwest
winds around 10-15 kts will diminish during the evening hours. South
to southwest winds will develop Thursday afternoon with gusts
generally at 15 to 25 kts. Although coverage will be less,
thunderstorms will develop again on Thursday afternoon.

&&

.SPOTTER INFORMATION STATEMENT...Spotters are encouraged to report
any significant weather or impacts according to standard operating
procedures.

&&

DISCUSSION...Woods
AVIATION...Czyzyk

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
341 PM PDT Wed Aug 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0203 PM     Tstm Wnd Gst     Nellis AFB              36.23N 115.03W
08/12/2026  M71 MPH          Clark              NV   ASOS

            KLSV reported a peak wind of 71 MPH.

&&

AN

Preliminary Local Storm Report
National Weather Service Las Vegas NV
432 PM PDT Wed Aug 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0415 PM     Tstm Wnd Gst     1 N Desert Hills        34.57N 114.37W
08/12/2026  M61 MPH          Mohave             AZ   AWOS

            AWOS station KHII Lake Havasu City Airport.

&&

Preliminary Local Storm Report
National Weather Service Las Vegas NV
437 PM PDT Wed Aug 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 PM     Flash Flood      8 WSW Mountain Pass     35.44N 115.67W
08/11/2026                   San Bernardino     CA   Public

            Images taken by Mojave National Park Service
            personnel show mud and debris covering Cima
            Rd just south of Interstate 15. Debris is
            estimated to be 1 to 2 feet deep. Time is
            estimated based on radar.

&&

ASG

Preliminary Local Storm Report
National Weather Service Las Vegas NV
458 PM PDT Wed Aug 12 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0330 PM     Flash Flood      6 ENE New Kingman-Butle 35.30N 113.93W
08/12/2026                   Mohave             AZ   Public

            Images and videos show flash flooding along
            Route 66 between Kingman Airport and Valle
            Vista. Time is estimated based on radar.

&&

ASG