038
FXUS65 KVEF 140458
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
958 PM PDT Thu Aug 13 2026

.KEY MESSAGES...

* Thunderstorms are expected this afternoon and evening, bringing
  localized flooding, gusty winds, and hail.

* Additional thunderstorms develop tomorrow afternoon, followed by a
  drying trend this weekend and next week.

* Temperatures cool through tomorrow, then slightly rebound over
  the weekend and into next week.

&&

.DISCUSSION...Through Wednesday.

The current setup aloft involving a trough off the Pacific Coast and
high pressure over the southeastern United States allows for
favorable moisture advection into the forecast area. Dew points
range from the upper 50s to the 60s across much of the Mojave
Desert, and reach into the 70s along the Colorado River.
Thunderstorms have already started to develop over the Sierra and
high terrain in southern Nevada including the Spring Mountains and
McCullough Range. A faster storm motion may help subdue the flooding
risk for much of the Mojave Desert, but increased storm coverage
over the southern Great Basin and northwestern Arizona brings
elevated flooding concerns to those areas. This morning`s 18Z
sounding shows cooler air aloft, bringing surface based CAPE up to
1600 J/kg with 41 knots of cloud layer shear. Gusty winds and
hail are within the realm of possibility for the stronger storms,
especially in northwestern Arizona and southern Nevada this
afternoon. Strong winds aloft may prove to be a limiting factor,
pushing storms off high terrain before strong vertical updrafts
can form. Convection should slow down after sunset.

The ridge starts to push west tomorrow, which will begin to limit
moisture availability for storms. However, the presence of the mid
level trough off the California coast will help maintain instability
needed for storm formation. Convection will begin in the afternoon
and last into the evening, albeit with less coverage compared to
today. The greatest potential for flash flooding will be in Lincoln
County and northern Mohave County, where storm coverage is the
greatest. Dry conditions return this weekend and next week as the
ridge grows west and moisture is shut off.

The building ridge will also bring an increase in temperatures
through the middle of next week. High temperatures rise to near
normal values by Monday, which means highs in the mid 100s for Las
Vegas. Moderate (Level 2 of 4) Heat Risk returns to valleys across
the Mojave Desert, with pockets of Major (Level 3 of 4) Heat Risk in
lower valleys of southern Mohave County.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast
Package...Typical light south to southwest winds are expected
overnight through Friday morning. After a dry night, convection is
expected to develop Friday afternoon in and around southern Nevada
into western Arizona. 40%-50% chance of thunderstorms after 18Z at
the terminals which could result in heavy rain, visibility under
5SM, sudden gusty winds, and CIGs below 8000ft. Outside of
convection, east to southeast winds are expected but will remain
under 8KT. Low confidence in the wind forecast Friday evening after
thunderstorms wane as wind direction may depend on afternoon
convection. Light winds will eventually set up Friday night. VFR
conditions with SCT-BKN clouds over 10kft are expected through the
period.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Isolated showers and
thunderstorms will persist a few more hours in the Southern Great
Basin tonight before diminishing after 08Z. Any lingering storms
could produce brief heavy rain, lightning, and sudden gusty winds
over 30 KT. After convection ends, typical overnight wind patterns
are expected the rest of the night. Convection will develop again
Friday afternoon, mainly across southern Nevada and western Arizona.
Low chance that isolated storms develop near KDAG as well as in the
Colorado River Valley, but confidence is too low to include in this
TAF package. Any storms could produce lightning, heavy rain, sudden
gusty winds, and CIGs below 8000ft. Outside of convective
influences, south winds around 10 will develop Friday afternoon.
Wind and convection will diminish after sunset Friday as typical
wind pattern return to most locations. Low confidence in wind
direction and speeds in the Colorado River Valley as a push of north
winds look possible. VFR conditions with SCT-BKN clouds over 10kft
are expected through the period.


&&

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

&&

$$

DISCUSSION...Meltzer
AVIATION...Nickerson

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