170
FXUS65 KVEF 131915
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1215 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 18Z Forecast Package...
Expecting south-southeast breezes to kick in this afternoon with
gusts 15-20 knots, but once thunderstorms begin to develop in the
vicinity, the wind forecast becomes low confidence. Models are keen
on pushing storms into the valley, with best chances between 20z and
00z, though activity may linger into the evening. Gusty outflow
winds are likely, with potential for heavy rain and reduced
visibility should a storm move over the airfield. Lowest cloud bases
between 8-10kft. Calmer conditions should resume by 06z (if not
earlier) and persist through the morning hours on Friday. Storm
chances return Friday afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Another round of
afternoon convection today, mainly across southern NV, northwestern
AZ, and Inyo County. Storms will likely produce strong outflow
winds, heavy rain, and frequent lightning. Most of this activity
should wane after sunset, but may linger through the night across
the lower Colorado River Valley and Mohave County. Outside of
convective influences, expecting light breezes generally from the
south. Lowest cloud bases 8-12kft.

&&

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

&&

$$

DISCUSSION...Meltzer
AVIATION...Woods

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