070
FXUS65 KVEF 132143
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
243 PM PDT Sun Jul 13 2025

.KEY MESSAGES...

* Isolated convection capable of producing sudden gusty winds
  will be possible across northwestern Arizona this afternoon.

* Hotter than normal temperatures will continue into the week,
  with temperatures peaking on Monday when multiple heat headlines
  are in effect.

* Monsoonal moisture will return to the region late this week,
  bringing increased chances for afternoon showers and
  thunderstorms.

&&

.DISCUSSION...through next weekend.

Precipitable water values have increased into the 0.50 to 0.90 inch
range across Mohave County and portions of Clark and San Bernardino
counties. While modest, this moisture combined with 100 to 200 J/kg
of CAPE from surface heating in northwestern Arizona will be enough
to help fuel weak isolated convection in Mohave County this
afternoon. Given the dry low-levels of the atmosphere, most, if not
all, of the precipitation is expected to evaporate before making it
to the surface. These dry low-levels combined with evaporative
cooling mean that sudden gusty winds will be possible with any virga
showers that develop. Any convection that does develop will diminish
after sunset.

Temperatures today will be a degree or two hotter than yesterday,
with the warming trend continuing through tomorrow as the ridge of
high pressure continues to build over the Southwestern US. As
temperatures peak tomorrow, we will see widespread Moderate (Level 2
of 4) to Major (Level 3 of 4) HeatRisk across the southern Great
Basin and Major HeatRisk across portions of the Mojave Desert. As
such, an Extreme Heat Warning has been issued for Death Valley
National Park, Clark County, and the Lake Mead National Recreation
Area; and a Heat Advisory has been issued for the southern Great
Basin for tomorrow. In addition to hotter than normal
temperatures, much of our forecast area will continue to
experience hazy skies as smoke from area wildfires circulates
under the bubble of high pressure.

Our ridge of high pressure will weaken and retreat in response to a
shortwave moving through the northwestern US. These falling 500 mb
heights will allow for temperatures to "cool" back down to near
normal during the middle of the week. Meanwhile, a cut-off low will
develop off the coast of the Baja Peninsula during the middle of
the week, which will help to transport moisture back into the area
towards the end of the week. There still remains uncertainty
regarding the magnitude of this moisture increase and how far into
our forecast area the moisture will penetrate, both of which will
play a role in precipitation chances, amounts, and impacts.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast Package...Winds
will remain relatively light, 10 knots or less, and will tend to
follow typical diurnal directional trends. There is a chance that
this afternoon`s southeasterly winds may briefly and occasionally
exceed 10 knots. Isolated virga showers will be possible in the
Peach Springs corridor this afternoon and will have the potential to
produce gusty and erratic winds. Chances of virga and associated
outflow impacting the terminal this afternoon are minimal, but not
zero. Smoke from area wildfires will remain aloft through the TAF
period. Temperatures will exceed between 18Z and 05Z, peaking around
111 degrees.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Winds will largely
follow diurnal directional trends with sustained speeds of 12
knots or less. Breezy up-valley winds will pick up in the Owens
Valley this afternoon with gusts up to 20 knots possible. Breezy
westerly winds will pick up across the western Mojave Desert this
evening, continuing into the overnight hours. Virga showers will
be possible across northwestern Arizona and far southern Nevada
this afternoon and may produce variable gusty outflow winds.
Slantwise visibility will continue to be impacted by wildfire
smoke aloft, but visibility restrictions at the surface are not
expected.

&&

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

&&

$$

DISCUSSION/AVIATION...Stessman


For more forecast information...see us on our webpage:
https://weather.gov/lasvegas or follow us on Facebook and Twitter