109
FXUS65 KVEF 031725
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1025 AM PDT Wed Sep 3 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.

&&

.DISCUSSION...Today through Tuesday.

Monsoonal moisture will surge farther north into the southern Great
Basin today. Meanwhile, a vorticity lobe will stretch along the
California-Nevada state line today, providing ample forcing aloft to
sustain widespread showers and thunderstorms again this afternoon.
Yesterday, morning convection overachieved, and resulted in thick
cloud cover through the morning and early-afternoon, which
resulted in a more stable environment than expected, thus fewer
thunderstorms than forecast. Today, clearing will slowly occur
through the morning, eventually exposing our southern zones to
sunlight. The resultant daytime heating will allow CAPE values to
increase to 500- 1000 J/kg across eastern San Bernardino County,
southern Clark County, southern Mohave County, and the Colorado
River Valley. Despite ample mid-and-upper level moisture, forecast
HRRR soundings continue to show dry air at the surface across our
southern zones, so gusts between 35 and 45 mph cannot be ruled
out with stronger thunderstorms. Additional threats include
frequent lightning, locally heavy rainfall, and isolated instances
of flash flooding this afternoon. Though forcing aloft is best in
the southwestern Great Basin - primarily across Esmeralda County
- morning cloud cover will keep that area relatively stable
through the day. We still expect moisture to gradually retreat
southeastward from our forecast area through the remainder of the
week and into the weekend; however, the speed at which the
moisture retreats has been delayed somewhat due to Hurricane
Lorena approaching Baja California. Daytime heating and remnant
forcing aloft coupled with this moisture return PoPs to our
eastern zones each day heading into the weekend.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package... A few
lingering showers will persist across the northern Las Vegas Valley
during the remainder of the morning. By mid afternoon additional
showers and thunderstorms will develop primarily over the higher
terrain. Highly uncertain for thunderstorm at the terminal but
erratic gusty winds associated with storms and outflow boundaries
are more likely by late afternoon and into the evening hours. For
Thursday afternoon and evening, scattered showers and thunderstorms
will be favoring the higher terrain. Temperatures are expected to
remain below 100 degrees both today and on Thursday.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...A band of lingering
showers will continue to push to the north and into Lincoln County
through the early afternoon. New shower and thunderstorm develop
will occur during the afternoon and early evening hours favoring
southern Nevada and the northern two thirds of Mohave County as well
as the higher terrain west of Bishop. Erratic gusty winds,
lightning, and brief MVFR/IFR conditions in heavy rain are expected
with storms that develop, with outflow winds possible away from
storms. Outside of convective influences, winds will generally
remain under 10KT and be somewhat variable this afternoon onward,
with VFR conditions prevailing. Scattered showers and thunderstorms
on Thursday afternoon and evening will once again favor the terrain.

&&

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

&&

$$

DISCUSSION...Soulat
AVIATION...Czyzyk

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NWS Flagstaff Office