805
FXUS65 KVEF 302205
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
305 PM PDT Sat Aug 30 2025

.KEY MESSAGES...

* Dry conditions and near to above normal temperatures through the
  holiday weekend.

* A mid-week influx of monsoonal moisture brings precipitation
  chances up and temperatures down.

&&

.DISCUSSION...through Friday.

Ensemble guidance shows an upper-level ridge amplifying over the
western US this weekend. This will drive temperatures above normal,
with a peak on Monday. At that point, highs are forecast to be 2-6
degrees above normal for early September, resulting in widespread
moderate and isolated major HeatRisk across the area. Meanwhile,
precipitation chances remain largely below 10%, only exceeding this
value in eastern Mohave County Monday afternoon (10-20%).

After Labor Day, the high shifts eastward and an area of low
pressure develops off the West Coast. These features induce a more
south-southeasterly flow that advects monsoonal moisture into the
region, increasing precipitation chances. Latest NBM has fairly
widespread 10-25% PoPs, but the greatest chances appear to be in the
Sierra and along/south of the I-15 corridor. With no obvious forcing
mechanisms, more specific forecasting of convection will likely have
to be done on a day-by-day basis as preceding convection and cloud
cover will greatly influence the daily evolution of precipitation
chances. Regardless, any storms that do form will pose a risk of
flash flooding and strong outflow winds.

&&

.AVIATION...For Harry Reid...For the 00Z Forecast Package...Winds
remain light and follow typical, daily patterns through Sunday
evening. There is a ~20% chance that winds briefly get up around 10
knots during the afternoon and evening hours, but speeds will
largely be 4-8 knots throughout the day. Mostly clear skies with
just a few mid-level clouds over the high terrain in the afternoon.
Temperatures remain near 100F until 02z, and should exceed 100F
between 21z and 02z Sunday afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 00Z Forecast Package...Light breezes that
follow typical, daily patterns can be expected across the region
today and tomorrow. The only exception to this is the lower Colorado
River Valley where northerly winds are forecast to be in the 8-15
knot range through Sunday morning. Mostly clear skies with just a
few mid-level clouds over the high terrain in the afternoon.
Wildfire smoke should stay west of the Sierra Crest, so not
anticipating any visibility reductions in the Owens Valley. However,
weak convection on the Sierra Sunday afternoon may induce some
erratic, gusty outflow winds in the Owens Valley (20% chance).

&&

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

&&

$$

DISCUSSION/AVIATION...Woods


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