026
FXUS65 KVEF 052353
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
453 PM PDT Sat Sep 5 2026

.KEY MESSAGES...

* Shower and thunderstorm chances increase 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.

The primary forecast concern involves a moisture surge from
Hurricane Marie, currently located several hundred miles off the
southern tip of the Baja Peninsula. Southwesterly flow aloft over
the southwestern United States will draw moisture from the system
into the region, bringing PWATs into the 1.0 to 1.5 inch range. The
approach of a 500 mb perturbation in the flow pattern supports the
development of a band of precipitation stretching southwest to
northeast along the Interstate 15 corridor. However, a slight shift
to the north or south could bring much higher precipitation amounts
to otherwise dry areas. Widespread cloud cover and the early morning
timing of the mid-level perturbation support widespread stratiform
precipitation rather than convective thunderstorms. Flow
perpendicular to certain mountain ranges is an excellent setup for
orographic lift and the greatest precipitation totals are expected
over high terrain. On the Spring Mountains, there is a 70 percent
chance or greater of one inch of precipitation over 24 hours over
8,000 feet in elevation and a 30 percent chance of two inches of
precipitation. Totals in the Las Vegas Valley will be far lighter,
but there is a 20 to 40 percent chance of at least one quarter inch
of rain in 24 hours. Roadway ponding and running washes are possible
across much of the Mojave Desert. Precipitation should end on Sunday
night as the disturbance moves inland.

Warmer and drier conditions are expected on Labor Day as heights
aloft start to increase again. High pressure will continue to build
and move west through the workweek. The position and strength of the
high will affect how much moisture is is able to draw into the
western United States, from both tropical systems and traditional
monsoonal sources. Temperatures are also dependent on precipitation
and cloud cover, but rising heights aloft should generally send
highs back towards normal values for early September.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...South-
southwest winds with gusts between 20 and 25 kts expected into this
evening before winds decrease to around 10 knots or less. Expect
gradually increasing cloud cover this evening with clouds continuing
to increase and lower overnight. Shower chances will develop as
early as 12Z, but more likely after 15Z with the potential of seeing
light to moderate rain from 15Z through 01Z. CIGs will generally
remain around 10kft, but could drop to around 4kft at times during
the afternoon along with a 10% chance of visibility reductions less
than 6SM. Temperatures will remain below 100F through at least
Tuesday.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Gusty south-
southwesterly winds expected into this evening this afternoon with
gust speeds between 20 and 30 kts. The exception will be KDAG which
will gust from the west. Winds will gradually decrease this evening
with speeds generally less than 10 knots for most areas. Expect
gradually increasing cloud cover this evening with CIGS likely
around 10-15kft by morning for all the TAF sites except for KBIH
where SCT-BKN high clouds are expected. Shower chances will start to
increase after 12Z for the Colorado River Valley TAF sites, KDAG,
and Las Vegas Valley TAF sites, but as this rain band shifts north,
it will mainly impact KDAG, KDRA, and the Las Vegas Valley TAF sites
after 15Z. CIGs generally around 10kft, but may lower between 4-6kft
with some heavier showers through the day. There is also a 10%
chance of visibility reductions less than 6SM.

&&

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

&&

$$

DISCUSSION...Meltzer
AVIATION...Gorelow

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