528
FXUS65 KVEF 302028
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
128 PM PDT Mon Jun 30 2025

.KEY MESSAGES...

* Hot temperatures continue, peaking today and Tuesday and slowly
  moderating thereafter.

* Increasing moisture will result in a return of thunderstorm
  chances, first across Mohave County on Tuesday, then expanding
  across southern Nevada and eastern San Bernardino County through
  Wednesday. Storm chances may linger across northwestern Arizona
  through Thursday.

&&

.DISCUSSION...

This afternoon, highs are well on their way to topping out around 3
to 7 degrees above normal with current temperatures in the mid 90s
and lower 100s across lower elevations, and 80s in the mountains.
Per latest water vapor imagery and 500hPa RUC analysis, a
negatively-tilted ridge remains anchored over the Four Corners
Region, with an approaching trough to the west off of the Central
California Coast that will gradually translate eastward the next
several days. Decreasing thicknesses with this trough as well as
increasing moisture will result in a slow moderation of
temperatures, with highs Tuesday similar to today, but gradually
cooling down and topping out closer to normal by the end of the week
and into this weekend. Fortunately, HeatRisk largely remains in the
Minor to Moderate range, precluding the need for any heat-related
headlines, though those spending time outdoors will still need to
ensure they stay hydrated and as cool as possible.

Ahead of the approaching trough, monsoonal moisture will continue
increasing over the region. This increase in moisture is already
underway today, with precipitable water (PWAT) values over southern
reaches of the forecast area already gradually working toward 100
percent of normal. This increase will be more substantial Tuesday
and especially on Wednesday, as PWATs increase to around 125 to 150
percent of normal per latest ensemble guidance, focused particularly
across southern Nevada and northwestern Arizona. This moisture,
coincident with the approaching trough to the west and its
associated ascent will yield increasing storm chances. Storm chances
begin ramping up across Mohave County Tuesday afternoon and evening,
gradually expanding northward and westward through Wednesday, with
current expectations for storm potential to peak Wednesday afternoon
into Wednesday evening. Storm chances look to linger into Thursday,
particularly across portions of Mohave County, though the timing of
the aforementioned trough will make a difference as it ushers in
drier air, shunting moisture and storm chances eastward. In its
wake, a return to dry and breezy conditions is expected for the end
of the week through the upcoming weekend.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...Winds
will gradually veer around to the south and southwest through
this afternoon, with another round of elevated and gusty winds
expected this afternoon through early evening. While prevailing
winds will be south-southwesterly, some variability is possible
during peak heating with gusts to around 20KT, intermittently
higher. Gusts diminish after sunset, with a repeat expected on
Tuesday as gusty south-southwest winds develop late in the period.
VFR conditions will prevail, with intermittent midlevel clouds
throughout the forecast period. Temperatures today will exceed 100
degrees between 19Z-04Z, peaking at 106 degrees around 23Z-01Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Gusty southerly to
southwesterly winds will develop areawide this afternoon, with
gusts to 20-25KT common at area terminals. Slightly stronger gusts
are expected across the Owens Valley in the vicinity of KBIH,
with gusts expected to diminish after sunset. The exception will
be across the Western Mojave, where gusts to 25KT will continue
through late evening. Thereafter, winds generally settle into
typical diurnal patterns with speeds around 10KT or less, with
VFR conditions prevailing through the forecast period.

&&

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

&&

$$

DISCUSSION/AVIATION...Phillipson


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