Severe Thunderstorm Warning 20, NWS Las Vegas, NV

Area Forecast Discussion
National Weather Service Las Vegas NV
1245 PM PDT Tue Aug 11 2026

.KEY MESSAGES...

* Daily afternoon to evening isolated thunderstorm chances will
  continue through the week, with the greatest chances over higher
  terrain and some storms spreading into adjacent valleys. Storm
  chances will increase in the mid week.

* The high pressure is pushing eastward leading to cooling
  temperatures through the week.

&&

.DISCUSSION...
Monsoonal moisture will remain in place through the end of the week
with the deepest moisture generally located over the southern half
of the forecast area with PWATs of 1.00-1.50" across Lincoln, Clark,
southern Nye, eastern San Bernardino, and Mohave counties. Areas to
the north and west will generally remain around 0.75-1.00". Storm
chances are expected to increase over most areas as we start to see
more influence from trough located offshore. This will increase
shear and some cooling aloft. This combined with decent instability
areawide should lead to a better coverage of storms at least through
Thursday afternoon. Storms will still be hit and miss, but overall
coverage will increase. With the high PWs, flash flooding will
remain a concern along with strong gusty outflow winds along with
small hail. By Thursday and especially Friday into the weekend, the
trough offshore will begin to push inland. This will bring a drier
southwest flow into the region ending shower and thunderstorm
chances from west to east with only the far eastern areas of the
forecast area seeing thunderstorm chances over the weekend.

While the exiting high pressure will allow for more convection
over the next few days, it will also call for a cooling trend
through the end of the work week. Heat risk will drop through the
week with all of the southern Great Basin and Mojave Desert seeing
only Minor or Moderate readings. Lows look to fall into the 70s and
80s while highs reduce into the 90s to lower 100s. Temperatures look
to rebound slightly into the weekend, but not significantly.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...Somewhat
tricky afternoon forecast today in regard to thunderstorm chances.
Given the latest satellite imagery and model runs, thinking cloud
cover will limit instability in Vegas, keeping storms off to our
southwest. However, confidence in this is moderate. There are a few
model solutions that try to bring isolated storms into the southern
valley in the late afternoon, but better chances exist tomorrow
(~30%). Otherwise, breezy south winds continue, weakening after
sunset. Cloud bases at or above 12kft. Temps above 100F between 18z
and 03z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Scattered showers and
isolated storms continue across central/eastern San Bernardino
County and southern Mohave County this morning. Expecting this
activity to wane over the coming hours, with additional development
later today in areas to the west and north. Main concerns will be
gusty outflow winds and localized downpours. Activity should begin
to wane after sunset, but may start again early Wednesday morning
across our far southeastern areas. Cloud bases at or above 10kft.

&&

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

&&

DISCUSSION...Gorelow
AVIATION...Woods

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