607
FXUS65 KVEF 210558
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1058 PM PDT Mon Jul 20 2026

.KEY MESSAGES...

* Monsoonal moisture remains in place over the region through the
  upcoming weekend, maintaining daily thunderstorm chances.

* Seasonably hot temperatures continue, with a warming trend
  expected midweek onward.

&&

.DISCUSSION...Through Sunday.

Scattered showers continue drifting westward across portions of
Inyo and San Bernardino Counties early this afternoon, while
isolated thunderstorms have started developing over the higher
terrain of western Lincoln and northern Clark Counties. Similar to
previous days, most convection will remain anchored to the higher
terrain, with movement and additional development across lower
elevations contingent upon outflow boundary interactions. CAMs are
in agreement that scattered thunderstorms will develop over
southwestern Utah and northwestern Arizona this afternoon, with
this activity translating westward through this evening. Cell
training as well as slow storm motion will lend to a continued
heavy rain and flooding threat, especially for any locations that
have received appreciable rainfall over the past several days.
Additionally, showers and isolated thunderstorms look to linger
past midnight across southern Nevada, with another early start to
convection Tuesday morning. However, convective trends during the
morning are dependent on how much convective debris from this
afternoon and evening`s convection lingers, potentially limiting
the potential early in the day on Tuesday. However, by Tuesday
afternoon, scattered thunderstorms are expected to develop over
the Sierra, southern Great Basin, and northwestern Arizona once
again, with continued concerns for locally heavy rain, flash
flooding, and downburst winds with the strongest storms.
Precipitable water values, which have held around 2 to 3 standard
deviations above normal for several days, are progged to gradually
decrease midweek onward in response to a developing trough off of
the Pacific Northwest. The strength and amplitude of this feature
will dictate just how much drying occurs, though the overall
trend in the ensembles heading into the weekend is for
precipitable water values to decrease closer to normal for late
July. That said, thunderstorms remain in the forecast each day,
with chances gradually decreasing through the weekend.
Additionally, a weak inverted trough/easterly wave is progged to
finally move westward out of West Texas over the next 24 hours,
though model consensus is that this wave will be tempered out over
eastern Arizona, and not quite make it far enough westward to
have a large impact on local monsoon activity. While ensembles are
in agreement regarding the aforementioned trough developing off
of the Pacific Northwest, the devil is in the details, and the
precise trajectory and depth of this system as well as the
location of the ridge will dictate monsoon potential later this
week and beyond, so stay tuned.

In addition to daily thunderstorm chances, each day through the
upcoming week will also remain hot and muggy. Temperatures will
remain near seasonal normals, through midweek, with a warming
trend expected thereafter with temperatures expected to reach
around 5 degrees above normal in time for the weekend. Monsoonal
moisture and lingering overnight cloud cover due to afternoon and
evening thunderstorms will maintain above normal low temperatures.
Thus, little relief will be felt overnight, and we will continue
to observe widespread Minor and Moderate (Level 1 and 2) Heat Risk
each day through midweek, with pockets of Major (Level 3) Heat
Risk developing late week into the weekend. Those who will be
outdoors will need to ensure they stay hydrated and take breaks in
the air conditioning whenever possible.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...Winds
overnight will be southwest around 8 knots for much of the period.
There will be a possibility of east to southeast outflow winds
impacting the valley between 06z-08z with gusts up to 25 knots. If
this occurs it should be brief and winds will gradually settle back
to the southwest. Vicinity showers expected Tuesday morning, but
thunder appears unlikely at this point (

NWS Las Vegas (VEF) Office