357
FXUS65 KVEF 180510
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1010 PM PDT Mon Aug 17 2026

.KEY MESSAGES...

* Temperatures will peak on Wednesday and Thursday, with above-
  normal afternoon highs and near-record morning lows.

* Monsoon moisture increases late this week into the weekend,
  accompanied by increased shower and thunderstorm chances.

&&

.DISCUSSION...Through next weekend.

Broad ridging continues building westward across the Desert
Southwest today, with increasing thicknesses and subsidence
lending to our current warming and drying trend. Most locations
will stay dry this afternoon, though there is around a 10 percent
chance for isolated showers to develop across the southern Great
Basin and northwestern Arizona, with gusty winds and an
occasional lightning strike the primary concerns. The building heat
will be the focus through late in the work week, with
temperatures continuing to climb to around 5 to 7 degrees above
normal Wednesday and Thursday. Lingering low-level moisture will
serve to temper afternoon highs somewhat, however, this same
moisture will allow for very mild/warm overnight lows in the upper
80s and lower 90s, expected to be near record warm lows for mid-
August. The prolonged, cumulative effect of the hot temperatures,
humidity, and little overnight relief will yield widespread
Moderate and Major HeatRisk, thus the Extreme Heat Warning remains
in effect for portions of southern Nevada, southeastern
California, and northwestern Arizona Tuesday morning through
Friday evening. An uptick in monsoonal moisture late week into the
weekend will provide relief, with a cooling trend expected in
both daytime highs and overnight lows.

The aforementioned uptick in moisture will be driven by a trough
progged to take shape off of the Pacific Coast late this week,
resulting in an eastward shift of the ridge of high pressure
closer to the Four Corners. Ensembles are in agreement that this
shift in the upper pattern will also allow for a return of
thunderstorm chances, possibly as early as Thursday afternoon for
portions of Mohave County, gradually expanding northward and
westward through the weekend. While precise timing and location
remains uncertain at this time, those who have outdoor plans late
week into the weekend should stay on top of the latest forecast
and plan accordingly. Stay tuned.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast
Package...Southwesterly winds of less than 10 knots become
variable by tomorrow morning. Southerly to southwesterly winds
return tomorrow afternoon, with occasional gusts between 15 and 20
knots, decreasing after sunset. Temperatures climb above 100
degrees between 18Z and 04Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Elevated westerly winds
persist at KDAG through the night, decreasing tomorrow before
returning tomorrow evening. Winds increase out of the south to
southwest in the Las Vegas Valley, Colorado River Valley, and Owens
Valley during the afternoon. FEW to SCT clouds between 10 and 20 kft
AGL continue through the TAF period.

&&

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

&&

$$

DISCUSSION...Phillipson
AVIATION...Meltzer

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