506
FXUS65 KVEF 202237
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
337 PM PDT Sun Sep 20 2026

.KEY MESSAGES...

* Dry and seasonable conditions will give way to increased
  precipitation chances and a relative cool down on Monday and
  Tuesday.

* Temperatures will recover during the second half of the week
  with low precipitation chances returning for northwest Arizona
  as we head into the weekend.

&&

.DISCUSSION...through Sunday.

Plenty of high clouds streaming into the area today ahead of an
upper low off the central California coast. This low will move
onshore tomorrow and provide the chance of showers and
thunderstorms (30 to 60%) to much of the region but will favor
Inyo County and the southern Great Basin. This convective activity
may continue well into the evening across Lincoln County.
Instability will be somewhat limited, generally, 100-300 J/kg.
Temperatures will cool marginally behind the low on Tuesday with
most locations 3 to 6 degrees cooler than high temperatures that
we will see today. The low will eject fairly quickly to the
northeast on Tuesday morning but there may be a few lingering
showers into the early afternoon in Lincoln County.

Generally, dry southwesterly flow will be in place for the rest of
the week and into next weekend. The exception to this is with the
ensemble guidance hinting towards a modest uptick in moisture
mainly south and east of Las Vegas on Thursday and Friday.
Currently, the best chances of precipitation associated with this
moisture are around 10 to 20 percent in Mohave County.
Temperatures will be around their seasonal normals on Wednesday
and increase a few degrees on Thursday and remain fairly flat into
the weekend.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...Winds
will follow typical daily directional patterns with some
variability through Monday morning, with speeds expected to remain
around 8KT or less. Early Monday afternoon, winds will shift to
the southeast, increasing to around 10KT with sporadic higher
gusts to 15-18KT expected, especially during the mid-afternoon.
These gusts will diminish as winds veer to the southwest around
sunset. VFR conditions will prevail with increasing mid-level and
high clouds with bases at or above 15kft. While showers are
possible over the mountains surrounding the Las Vegas Valley
Monday afternoon and evening, impacts are not expected at the
terminal.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Winds through Monday
morning will generally follow typical daily directional patterns
with speeds around 5-10KT. By early Monday afternoon, elevated and
at least intermittently gusty southeasterly winds are expected,
with gusts to 15-25KT common. Exceptions to this include the
western Mojave Desert/KDAG, where gusty winds early in the period
will shift to the west around 10-12KT this evening onward, as
well as across the northern Owens Valley/KBIH where up-valley
winds will gust to around 20KT through sunset. Showers and
isolated thunderstorms are expected to develop over the higher
terrain of Inyo County and the southern Great Basin Monday
afternoon, with potential impacts due to erratic gusty winds and
lightning at KBIH near and just beyond the end of the forecast
period. Otherwise, VFR conditions will prevail with increasing
clouds with bases at or above 15kft, potentially lower in the
vicinity of convection.

&&

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

&&

$$

DISCUSSION...Czyzyk
AVIATION...Phillipson

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NWS Las Vegas (VEF) Office