748
FXUS65 KVEF 051144
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
445 AM PDT Sat Sep 5 2026

.KEY MESSAGES...

* Breezy conditions persist today with a slight (5 to 15 percent)
  chance of isolated showers and thunderstorms in our southern zones.

* Shower and thunderstorm chances increase and spread across the
  Mojave Desert on Sunday as moisture surges northward.

* Drier conditions expected for Labor Day, though monsoonal
  moisture and warmer temperatures return midweek.

&&


.DISCUSSION...Today through Friday.

Generally expecting a quiet and dry day across the region today.
Will need to watch if showers and thunderstorms are able to develop
along a moisture boundary as it surges northward this afternoon,
particularly in southern Mohave County and the Colorado River Valley
south of Lake Mohave. Due to the dry low-levels, these showers and
thunderstorms may simply amount to virga with gusty winds from their
direction. Breezy south to southwest winds are expected again this
afternoon, with magnitudes slightly lower than yesterday`s winds
with gust speeds between 20 and 30 MPH in many locations.

The main concern in the forecast is Sunday as moisture is advected
up from the tropics, resulting in a plume of precipitation across
the region. PWATs climb over 1.00 inches by Sunday. Models are all
in decent agreement that this stripe of precipitation will develop
somewhere across the region, but exactly where is still in question.
The best guess is a band of stratiform rain setting up through the
western Mojave Desert through Clark County into southwestern Utah on
Sunday as this is where the signal for measurable rainfall is
highest. Areas south and north of this are where the uncertainty
exists, especially Death Valley, Pahrump, and Caliente to the north,
then Kingman and Bullhead City to the south. The other unknown for
this event is how much convection will be able to develop alongside
or within the rain band, but current instability fields are not
strongly supportive of thunderstorm development. The highest chance
for rainfall impacts will be the western Mojave Desert through the
Spring Mountains where there is about a 50% chance for over 0.50
inches of total rainfall Sunday and Sunday night (with a bulk of the
rainfall occurring before Sunday evening). Las Vegas may struggle to
see much rainfall due to rainshadowing from the nearby terrain, but
rain should fall at some point on Sunday in the valley. Roadway
ponding, minor flooding, and responses in typical flashy areas will
be possible where the heaviest rainfall does fall.

Things shut down Sunday night as the trough swings inland. On
Monday, PWATs dry out quickly as westerly anti-cyclonic flows sets
up aloft. After a cool down on Sunday with the rain and falling
heights, it will start warming back up on Monday as the trough lifts
out. After a down day on Monday, will need to monitor how moisture
moves back in from both the tropics in the Pacific as well as
monsoonal moisture as the high repositions itself somewhere over the
Southwest US. Temperatures will depend on how much moisture returns
to the region, but should remain at least near normal for this time
of the year.
&&


.AVIATION...For Harry Reid...For the 12Z Forecast Package...South-
southwest winds with gusts between 20 and 25 kts expected this
afternoon. Expect gradually increasing cloud cover after sunset
today. Periods of showers and a slight chance of thunderstorms
possible after 10Z Sunday with CIGs dropping to 8 to 10 kft. Light
showers expected after 15Z Sunday. Temperatures will remain below
100F through at least Tuesday.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Gusty south-
southwesterly winds expected this afternoon with gust speeds between
20 and 30 kts. The exception will be KDAG gusting from the west.
Expect gradually increasing cloud cover this afternoon through this
evening. Colorado River Valley TAF sites, KDAG, and Las Vegas Valley
TAF sites have a chance of shower and thunderstorm activity over the
terminal starting between 08 and 10Z. With precipitation, expect
CIGs dropping to 8 to 10 kft.
&&


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

&&

$$

DISCUSSION...Nickerson
AVIATION...Soulat

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