155
FXUS65 KVEF 231146
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
446 AM PDT Sat Aug 23 2025

.KEY MESSAGES...

* The Extreme Heat Warnings and Heat Advisories will continue
  through this evening with temperatures cooling as we head into
  next week.

* Similar to Friday, lingering cloud cover will limit instability
  across the central portion of our forecast area with convective
  development favoring the fringes of our forecast area.

* Chances for showers and thunderstorms will continue into next
  week.

&&

.DISCUSSION...through Friday.

Low temperatures this morning will be around 6 to 12 degrees warmer
than normal, which will help to keep HeatRisk elevated despite the
slight decrease in forecast afternoon high temperatures. As such,
the Extreme Heat Warnings and Heat Advisories look good to remain in
effect through later this evening. Temperatures will continue to
cool as we head into next week, dropping below normal beginning
Monday and Tuesday. Once they return, these cooler than normal
temperatures will continue through the end of the week.

Similar to yesterday, cloud cover from debris clouds from storms in
Arizona will limit instability across the central portions of our
forecast area. Current infrared and water vapor satellite imagery
show these debris clouds from earlier convection currently
working their way through our forecast area with additional clouds
beginning to push in from the south. It is these additional
clouds that will limit daytime heating, therefore decreasing
instability this afternoon. Convection is expected to initiate
along the fringes of our forecast area where daytime heating will
be maximized. Showers and thunderstorms will initially favor
higher terrain with additional development possible across lower
elevations as outflow boundaries move through. Strong outflow
winds, moderate-to-heavy rain, flash flooding, and frequent
lightning will be possible with any storms that develop. Outflow
winds from distant storms will have the potential to impact area
lakes, resulting in choppy waves and hazardous boating conditions.
Stronger, more robust storms across the southeastern portions of
our forecast area will be capable of 1 inch per hour rain rates or
greater.

Conditions look better on Sunday in terms of more widespread
convection across the area as HiRes models do not show debris clouds
moving through overnight and limiting instability during the day.
Chances for showers and thunderstorms will continue into next week
as moisture lingers across the region. Hazards will remain the same
with strong outflow winds, heavy rain, flash flooding, and frequent
lightning possible with any storms that develop over the weekend.
Around mid-week a weak shortwave trough will approach the coast of
California, with the potential to result in more widespread showers
and thunderstorms as lift from this trough overlaps with the
presence of monsoonal moisture. However, at this point, there
remains a wide envelope of possibilities when it comes to what
exactly we could see due to interensemble variability regarding the
evolution of this system.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...Lots
of debris clouds will be passing through this morning, which will
inhibit heating and likely delay the threat of thunderstorms today.
Storms could fire on the mountains as early as noon, but the better
chances for anything to affect the terminal should hold off until
late afternoon (if it occurs at all). The main concern with any
nearby storms will be erratic gusty winds, with a lower (but not
zero) chance of briefly heavy rain and lower ceilings. A few light
showers could persist into the night. Storms are expected to develop
on the mountains again around midday Sunday. Much lower confidence
in the temperature forecast due to the cloud cover. The best chances
for exceeding 100F should come between 18Z and 04Z.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...Lots of debris clouds
and a few light showers will continue moving through the region this
morning, with the greatest concentration southeast of Interstate 15.
These clouds will hold temperatures down for a while, causing low
confidence in the forecast for afternoon thunderstorms. The
mountains of Inyo and Esmeralda counties should see development by
noon, assuming that the debris clouds don`t inhibit heating that far
northwest. The mountains of Clark and San Bernardino counties
shouldn`t be far behind, followed by the mountains of Nye, Lincoln,
and Mohave counties. The main threats with storms will be erratic
gusty winds, locally heavy rain, and low ceilings with terrain
obscuration. Similar to Friday, most storms should die off by late
evening, with debris clouds and light showers persisting well into
the night. The threat of afternoon showers and thunderstorms will
continue across the region each day through at least Tuesday.
However, Tuesday and Wednesday have been consistently showing the
potential to be the most impactful days of next week in terms of
weather.

&&

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

&&

$$

DISCUSSION...Stessman
AVIATION...Morgan

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