133
FXUS65 KVEF 161151
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
451 AM PDT Wed Sep 16 2026

.KEY MESSAGES...

* Isolated-to-scattered showers and thunderstorms expected today
  and Thursday across our eastern zones.

* Elsewhere, expect breezy south-southwesterly wind gusts through
  the week with dry conditions and near-normal temperatures.

&&

.DISCUSSION...Today through Tuesday.

Expecting isolated-to-scattered showers and thunderstorms this
afternoon across Lincoln and Mohave counties, with chances
spreading into Thursday morning. While the southern Great Basin
remains situated under a dry southwesterly flow aloft, the
southern Mojave Desert will experience a south-southeasterly flow,
which will usher in 1.25 to 1.75 inches of PWAT into the region -
specifically southeastern Nevada and northwestern Arizona. In
addition to the moisture, there is a disturbance riding up the
Baja California that is currently highlighted by the NHC as having
a 10 percent chance of tropical storm formation in the next 48
hours. While this disturbance is unlikely to become a cyclone, as
it pushes northward, the vorticity maxima associated with it will
lead the development of showers and thunderstorms across southern
Mohave County / the lower Colorado River Valley this afternoon.
Additionally, energy riding along the upper-level trough across
the western CONUS has closed off over northern California this
morning and will begin its meander eastward across Nevada this
afternoon. The enhanced jet associated with this closed low will
combine with daytime heating to facilitate convection across
eastern Lincoln, eastern Clark, and Mohave counties, which is in-
line with the latest CAM guidance. That said, there is a noticable
PWAT gradient across the center of our forecast area, which could
act as a dryline, resulting in convection developing a bit
further west than guidance currently suggests. Will continue to
keep an eye on locations along and west of Interstate 15 as the
day progresses. As a result of ample instability and moisture,
thunderstorms that form are expected to be efficient rain- makers
with frequent lightning, which will elevate the risk of flash
flooding, particularly across Mohave County and underneath
training storms. Forecast HRRR soundings in south-central Mohave
County show over 1750 J/kg of SBCAPE, 750-1000 J/kg of DCAPE, 1.50
inches of PWAT, and 500 mb cooling (LIs around -4 degrees C), so
severe thunderstorms are likely as well.

The trough axis associated with the aforementioned closed low will
push through the forecast area today and Thursday, resulting in
elevated south-southwesterly winds with gust speeds generally
between 25 and 35 mph. Cannot rule out occasional gusts to 40 mph
in the higher terrain. Otherwise, persistent troughing over the
western CONUS will result in afternoon high temperatures near-
normal for mid-September. Cloud cover heading into overnight
periods may result in elevated morning lows, however.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...Gusty
southeasterly winds will develop by mid-morning, with gusts to
around 20KT expected. Early afternoon, winds veer to the south and
increase, with gusts around 25KT expected and sporadic higher
gusts closer to 30KT possible. While a brief lull in winds may be
possible after sunset, there is higher confidence that gusty winds
will persist through late evening before diminishing overnight.
Thunderstorm activity is expected to remain east of the terminal
over northwestern Arizona and the Mormon Mesa corridor, with VFR
conditions prevailing. FEW-SCT clouds with bases around 10kft can
be expected this afternoon and tonight, with temperatures
remaining under 100 degrees.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Winds will become
gusty out of the southeast by mid- morning, before shifting to
the south to south-southwest by early afternoon. Gusts to around
25KT will be common across the region, with slightly stronger
gusts to around 30KT possible in the northern Owens Valley and
along the Lower Colorado River Valley where up-valley winds will
develop. Winds across the western Mojave Desert will generally
remain westerly, with gusts to 20-30KT expected to develop mid-
afternoon and continue into the night. Elsewhere, gusts will
diminish by mid- to late evening. Thunderstorms are expected this
afternoon and evening over eastern areas, and especially over
northwestern Arizona, with impacts from lightning and gusty
outflow winds possible at both KEED and KIFP. FEW-SCT clouds with
bases at or above 10kft are expected this afternoon onward for
most of the region, with lower ceilings and greater coverage in
the vicinity of thunderstorms.

&&

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

&&

$$

DISCUSSION...Soulat
AVIATION...Phillipson

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