939
FXUS65 KVEF 041701
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1002 AM PDT Fri Sep 4 2026

.KEY MESSAGES...

* Drier, cooler, and breezy conditions expected through Friday.

* Rain and storm chances return Saturday afternoon and Sunday as
  moisture surges northward

* Drier conditions for Labor Day, monsoonal moisture and warmer
  temperatures may return mid next week.

&&

.DISCUSSION...Through Mid Next Week.

Upper troughing persists along the west coast into early next week
keeping southwesterly flow aloft for the Desert Southwest. This
pattern supports below average temperatures and breezy conditions
locally into the Holiday weekend. Hi-res short term models and
longer range guidance both show negative 850mb temperature anomalies
with this pattern, raising confidence that surface temperatures will
continue to run around 5 to as much as 10 degrees below normal...
translating to highs in the 80s-90s for Desert Valleys, low 100s for
the CRV and Death Valley, and cooler in the higher terrain.

In addition to cooler temperatures, breezy conditions are expected
through at least Saturday as mixing into an enhance mid level jet
brings stronger gusts down to the surface. The EC EFI has been
highlighting today and to some extent Saturday as the windier days
within the forecast period. High confidence exists in afternoon S-SW
wind gusts reaching 30-35 mph today and tomorrow... with today
likely seeing the more widespread wind gusts nearing 40 mph at
times. Highest wind gusts will likely be at higher elevations or in
wind prone valleys. While widespread wind gusts over 40 mph are not
expected, due to the lower wind threshold on area lakes, a Lake Wind
Advisory has been issued for both Lake Mead and Lake Mohave from
late Friday morning into Friday evening.

Attention shifts to the latter half of the weekend as tropical
moisture from Hurricane Marie is drawn northward ahead of the
aforementioned trough. While the main system will remain out at sea,
confidence is increasing in a surge of deeper moisture northward
into the region Saturday afternoon through Sunday. The 1.00" PWAT
contour is forecast to reach the lower Colorado River Valley early
Saturday afternoon, gradually expanding northward and into southern
Lincoln, Clark, and eastern San Bernardino counties by Sunday
morning, with the 1.50" line extending up the Colorado River. Both
PWAT and IVT are forecast to be several standard deviations above
normal for this time of year, further increasing confidence in a
pattern supportive of more widespread rain. A ~100kt upper jet
streak to the west places much of the Mojave desert in the right
entrance region in an area of enhanced lift. This combined with a
mid-upper shortwave moving north from the Pacific into the CRV will
provide enough lift to spark off an area of showers and isolated
convection beginning Saturday in the CRV and Mohave County, then
expanding in coverage and spreading northward Sunday over much San
Bernardino and Clark counties. Surface-based and MU CAPE looks
rather marginal this weekend, potentially limiting the amount of
convection and resulting in this being more of a stratiform type
rain with isolated thunderstorms due to excessive cloud cover.  More
sun, could certainly lead to more convection. With increased clouds
and convection in the area, Sunday will likely be the coolest day in
the forecast period as highs struggle to even reach 90F in Desert
Valleys.

Looking toward next week, longer range guidance shows drier air
filtering back into the region Labor Day and Tuesday. A
Southwesterly flow pattern looks to somewhat remain in place next
week, however guidance continues to hint at the upper jet retreating
northward as ridging tries to rebuild from New Mexico westward into
the Mojave Desert. While Monday and Tuesday look much drier than
Sunday, watching for signals that a monsoonal pattern may be trying
to set up again going into mid to late next week. Lower confidence
exists in the overall details, but confidence is slowly increasing
in a pattern supportive of monsoon activity returning, which is also
reflected in CPC`s 6-10 day precipitation outlook. In fact, CPC
highlights portions of the CRV and eastern Mojave Desert for slight
risk of heavy precipitation Sept 11-13th. CPC 6-10 day outlook now
shows a signal toward a pattern supportive of above normal
temperatures locally as ridging builds over the Southwest.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...South-
southwest winds continue throughout the TAF period, strongest during
the daytime hours with gusts 20-30 knots likely (90%). Probability
of seeing 35+ knots is ~10%. Clear skies with temperatures remaining
below 100F.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Gusty conditions resume
today with southerly to westerly gusts across the region of 20-30
knots. Breezes weaken after sunset, but remain elevated in most
spots overnight. Mostly clear skies with just a few high clouds
moving into our southern areas on Saturday.

&&

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

&&

$$

DISCUSSION...Moore
AVIATION...Woods

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