552
FXUS65 KVEF 231154
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
454 AM PDT Wed Sep 23 2026

.KEY MESSAGES...

* Slow warming trend through Saturday with temperatures 3  to 5
  degrees above-normal for this time of year.

* Isolated storms possible over Mohave County Thursday afternoon
  and evening.

* Potential tropical influence from Hurricane Polo on Sunday as
  moisture is brought northward.

&&


.DISCUSSION...Today through mid next week.

The first day of Fall certainly felt like it across the region as
temperatures were several degrees below normal and Las Vegas fell
below 70 degrees for the first time since May. The trough from
yesterday has since pulled off to the northeast with subtle ridging
and slightly above average heights setting up for the rest of the
week. Low level temperatures slowly warm each day through Saturday
supporting temperatures about 3-5 degrees above normal with highs in
the 90s to low 100s and lows in the 70s to low 80s for desert
valleys...cooler at higher elevations. Briefly cooler temperatures
possible by the latter half of the weekend as a trough approaches
the region; however long range guidance shows ridging quickly
building in for next week with higher confidence for near to above
normal temperatures persisting through the end of the month.

Generally dry conditions for the majority of the Mojave Desert and
lower Great Basin the rest of the week, with the exception of Mohave
County where isolated storms will be possible Thursday afternoon and
evening (and to a lesser extent Wednesday evening). Weak troughing
sits off the coast of Southern California while ridging builds over
Texas and the southeast, placing Arizona and the Four Corners in a
modest baroclinic zone with numerous waves riding northward through
it. Short term guidance continues to hint at a mid level wave
tracking northward into Central Arizona on Thursday, working to
advect greater moisture northwestward into the area and providing
lift for afternoon/evening showers and thunderstorms. Conditions
look favorable for convective development Thursday with sufficient
MUCAPE, DCAPE, and moisture availability, and lift. At this time,
isolated storms are possible in Mohave County with brief periods of
heavy rain, lightning, and gusty winds possible with any storm.
Convection at this time should be limited to Mohave County as much
drier air remains in place further north and west.

Late weekend into early next week, ensembles and cluster analyses
indicate another trough approaching the west coast Sunday. Strong
southwest flow ahead of the trough could potentially advect tropical
moisture northward from the numerous hurricanes in the Eastern
Pacific. Deterministic and Ensemble guidance show this setting up to
some extent...however confidence still remains low at this time on
the exact evolution of this pattern with many moving parts in play.
Thinking an increase in tropical moisture northward will increase
clouds and the chance for precipitation while decreasing
temperatures a few degrees. PoPs have been added to the Sunday-
Monday timeframe for the Mohave Desert to account for this.
&&


.AVIATION...For Harry Reid...For the 12Z Forecast Package...Expect
light and diurnal winds through the TAF period with speeds generally
below 8 kts. There is a 10 percent chance of gusts over 10 kts this
afternoon; however, if there are gusts, they will be isolated. No
operationally significant cloud cover through the TAF period.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Expect light and diurnal
winds through the TAF period. The exception will be KBIH where south-
southeasterly winds will peak around 10 kts and cannot rule out an
occasional gust. No operationally significant cloud cover through
the TAF period.
&&


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

&&

$$

DISCUSSION...Moore
AVIATION...Soulat

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