Severe Thunderstorm Warning 54, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
350 PM PDT Thu Sep 4 2025

.KEY MESSAGES...

* Monsoonal moisture remains in place today before slowly retreating
  eastward out of the region, shifting the best precipitation
  chances further east each day through Saturday.

* Dry conditions and relatively cooler temperatures are expected
  to return next week.

&&

.DISCUSSION...Today through Thursday.

Deep moisture is currently in place from the eastern half of San
Bernardino County and across Clark and Mohave counties. PW values
are ranging from 1.25-1.75 inches and little change will take place
with that moisture through tomorrow as the circulation of Tropical
Storm Lorena helps maintain that deep moisture. The direct impacts
from Lorena continue to be much further south and east and not a
factor here. Brief heavy rainfall will be the main concern with
these thunderstorms and although not limited to the higher terrain
the storms will favor the higher terrain. Unlike yesterday the
convection began much earlier around 18Z but is also expected to
diminish earlier, primarily by sunset. The exception is the
potential for a bit more organized area of convection that forms
over Lincoln County and southwest Utah to push its was to the south
and into eastern Clark and northern Mohave County toward midnight.
Several hi-res models bring those storms all the way through Mohave
County through daybreak. At this point it looks like the these
storms will be primarily east of the Las Vegas Valley. Convection on
Friday will favor southern Nevada and northwest Arizona. Over the
weekend much drier air will continue to push in from west to east
with the deeper moisture limited from the Colorado River Valley and
points east on Saturday and by Sunday the drier air will sweep into
the entire forecast area, although the EPS does linger the moisture
a bit longer maintaining it through Sunday.

A deep, early season trough along the West Coast by Tuesday will
continue to maintain dry air and also produce lowering heights aloft
which will result in a gradual decrease in temperatures through
Thursday. Highs should be 5 to 10 degrees below average by
Wednesday, which means highs in the low 90s in Las Vegas.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...Showers
and thunderstorms in the Las Vegas Valley quickly came to an end
this afternoon. The HRRR has pushed the overnight convection further
east and is less aggressive so at this point the primary impacts
overnight would be convection in the Mormon Mesa and Peach Springs
corridors. Another afternoon and early evening of convection, most
favored between 21Z and 00Z on Friday primarily focused over the
higher terrain Outside of thunderstorm influences, winds generally
remain around 8kt or less and be somewhat variable, with VFR
conditions prevailing.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...This evening and
overnight, showers and thunderstorms will continue over eastern
Lincoln and portions of Mohave County. Elsewhere convection in the
vicinity of KBIH should decrease soon after sunset. Erratic gusty
winds, lightning, and brief MVFR/IFR conditions in heavy rain are
expected with these storms, with outflow winds possible away from
storms. On Friday afternoon and evening thunderstorms will develop
again and favor the higher terrain in southern Nevada and northwest
Arizona as well as far eastern San Bernardino County.
&&

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

&&

DISCUSSION...Czyzyk
AVIATION...Czyzyk

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Preliminary Local Storm Report
National Weather Service Las Vegas NV
604 PM PDT Thu Sep 4 2025

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

0551 PM     Flash Flood      10 W Lone Pine          36.59N 118.23W
09/04/2025                   Inyo               CA   Law Enforcement

            California Highway Patrol reported multiple
            mud and rock slides on Whitney Portal Road
            at 551 PM.

&&

MW