845
FXUS65 KVEF 182021
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
120 PM PDT Fri Sep 18 2026

.KEY MESSAGES...

* Dry conditions through the weekend with near normal temperatures

* Chances of precipitation return Monday and Tuesday

* Above normal temperatures return mid to late next week


&&

.DISCUSSION...Through Thursday.

Drier conditions are setting up for the weekend for the Desert
Southwest as an upper trough over the Northwest tracks east and
brief ridging sets up over the region. Monsoonal moisture is still
lingering today for portions of Southern Nevada and NW Arizona,
however much drier air is expected to overspread the region later
tonight and into Saturday. Observations today show dew points about
10 degrees lower than this time yesterday, but still in the 50s for
many areas, while locations just west of Las Vegas are significantly
drier. Satellite imagery shows a few cumulus clouds developing this
afternoon, but a mid level cap and dry air advection should prevent
anything from developing. Brief ridging this week will be relatively
weak compared to what has been observed this summer, so not
expecting a major warm up. Both 850mb and near surface temperature
anomalies will be near to slightly above normal for this time of
year. Expect max temperatures in desert valleys to range from the
90s to low 100s with lows generally in the 70s...cooler temperatures
in higher elevations.

Going into early next week, another upper trough kicks out the ridge
in place as it approaches Southern and Central California late
Sunday. Upper level moisture advection ahead of the trough should
bring widespread high clouds to the region beginning Sunday, then
low level moisture increases Monday into Tuesday as the system
pushes inland into Central Nevada. Ensemble means indicate a
resurgence of PWATs of 0.50 to 1.00 inch early next week for the
Colorado River Valley and Southern Nevada. Cooler air aloft under
the trough will help increase instability somewhat to bring a return
of PoPs to the region, with best rainfall chances in the Sierra and
Southern and Central Nevada Monday and Tuesday. Overall moisture
availability is rather limited and instability is marginal, so not
too concerned with widespread heavy rainfall or flooding at this
time. Current QPF looks fairly low and some spots could remain dry
through the period. With the presence of clouds and precipitation,
expect near normal temperatures the beginning of next week.

By Mid-week, mid and long range guidance are coming into consensus
that broad ridging returns to the Desert Southwest, which will allow
temperatures to climb back to above-normal for this time of year.
The chances of at least Moderate Heat Risk are at or above 50%
Wednesday through the end of next week, particularly for desert
valleys and the CRV.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...
Southerly winds (160 to 200 degrees true) are expected into the
early evening, with occasional gusts to around 30 knots possible.
Winds will diminish after sunset, with directions remaining out of
the south to southwest into the early morning hours. Light and
variable winds are expected early Saturday morning, followed by a
period of light north to northeast winds (020 to 060 degrees true)
from late morning through early afternoon. Southeast to southwest
winds return by late tomorrow afternoon and evening, although speeds
are expected to remain 10 knots or less. VFR conditions will prevail
through the TAF period.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Southeasterly to
southwesterly winds will continue across the region this afternoon,
with gusts of 20 to 30 knots possible into the early evening. One
exception will be in the northern Owens Valley, including KBIH,
where winds will likely remain northerly through the TAF period with
speeds staying below 10 knots. Another exception will be across the
western Mojave Desert, including KDAG, where gusty westerly winds
will increase this evening and persist well into the night. All
other locations should see winds diminish to 10 knots or less after
sunset. VFR conditions will prevail in all areas through Saturday.

&&

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

&&

$$

DISCUSSION...Moore
AVIATION...Planz

For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter