119
FXUS65 KVEF 170457
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
957 PM PDT Wed Jul 16 2025

.KEY MESSAGES...

* Temperatures decrease throughout the end of the week, followed by
  a gradual rebound over the weekend.

* An increase in monsoonal moisture Thursday through Saturday will
  result in increased chances for afternoon showers and
  thunderstorms, some of which could produce heavy rain and gusty
  winds.

&&

.DISCUSSION...through Tuesday.
Upper low off the southern California coast will help to draw up
some monsoonal moisture over the next couple of days and bring
scattered showers and thunderstorms to the region. Precipitable
water over southwest Arizona has been increasing through the day
with the 14Z Yuma sounding showing 1.51" of PW with the latest 18Z
Yuma sounding showing 1.71". Early this afternoon, the 1.00" PW line
looks to be situated near Searchlight and will continue to advect
north overnight with much of the southern half of the CWA seeing at
least a inch of PW by Thursday morning. Conditions were a little too
stable this afternoon to generate anything more than a couple of
isolated thunderstorms over Mohave County and some isolated virga
showers over southern Nevada. By Thursday, with deep moisture in
place combined with much better instability we should be more
scattered showers and thunderstorms stretching into southern Nevada
and southeast California. Cape values around 500 j/kg along with LIs
around -2/-3 should allow for these storms to develop late morning
and continue through the afternoon. With PWs being close to 200% of
normal, there could some areas of flash flooding. Where conditions
are a bit drier, like western San Bernardino, Inyo, and central Nye
counties, gusty outflow winds could be more a concern.

The deep moisture will peak on Friday as the upper low off the
southern California coast lifts north and tracks northeast through
the forecast area. Another day of scattered showers and
thunderstorms expected over much of the region. Again, we will need
to watch for areas of flash flooding along with strong gusty winds.

Moisture will start to wane on Saturday as the upper low moves away
and a westerly flow sets up over the region. We can still expect to
see some isolated storms, but most should be confined to the eastern
areas of the CWA. By Sunday, most of the moisture should be east of
the area with dry conditions forecast across the CWA. Of course,
this time of year that could change quickly.

High temperatures in most areas are expected to be near or below
normal on Thursday and Friday. Some places, including Las Vegas, may
not reach 100 degrees F on Friday ( 49% chance that Las Vegas
remains below 100F).  Readings will rebound over the weekend and
early next week, but only back to near-normal levels.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...The
primary aviation concern this forecast period will be
thunderstorms that could impact the Las Vegas Valley during the
afternoon and early evening. Gusty, erratic outflow winds and
lightning are expected, potentially impacting the terminal even
from distant storms, with brief downpours producing MVFR or IFR
conditions also possible. Timing details will be refined in later
issuances. Otherwise, southerly winds will prevail outside of
storms, with sustained speeds 10-12KT and gusts to 15-20KT late
morning through the evening. VFR conditions and ceilings around
12kft are expected away from convection, with improvement in
ceilings expected overnight with lighter winds through daybreak.


For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Las Vegas Valley
terminals generally follow similar trends to KLAS, with
thunderstorms expected to develop during the afternoon and early
evening. The main concerns will be lightning and erratic, gusty
outflow winds. Showers and storms look to impact the Lower
Colorado River Valley and Mohave County beginning mid to late
morning, with an uptick in convection during the afternoon.
Outside of storms, winds across the region will generally be
southerly to southeasterly, with gusts to around 15-25KT,
particularly during the afternoon. The exception will be across
the Western Mojave Desert, including KDAG, where westerly winds
tonight will veer to the east late morning, before returning to
the southwest after 03Z. VFR conditions will prevail away from
convection, with FEW-BKN clouds around 10-15kft.

&&

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

&&

$$

DISCUSSION...Gorelow
AVIATION...Phillipson

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