307
FXUS65 KVEF 160746
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1245 AM PDT Sun Aug 16 2026

.KEY MESSAGES...

* Isolated showers and thunderstorms will be possible this afternoon
  and evening across the higher terrain of southern Nevada,
  southeastern California, and northwestern Arizona.

* Temperatures will steadily increase throughout the week, with
  areas of Moderate-to-Major HeatRisk developing across the Colorado
  River Valley, Death Valley, and portions of the Las Vegas Valley.

&&

.DISCUSSION...through Saturday.

The anomalous moisture that has helped to fuel storms over the past
few days, will decrease during the first half of the week as the
upper-level flow becomes more southwesterly-to-westerly thanks to
the ridge building over the area. However, first, this southwesterly
flow will help to advect mid-level moisture from Tropical Depression
Hernan into the region overnight. This moisture will bring increased
cloud cover to the region and a 15 to 30% chance for showers and
thunderstorms in the higher terrain of southern Nevada, San
Bernardino County, and Mohave County today. Storms today will be
less robust than those we have seen over the past few days, with the
primary concerns being localized moderate-to-heavy rain, lightning,
and erratic outflow winds. Any storms that develop will diminish
after sunset with the loss of daytime heating. Beyond today,
decreasing moisture combined with increasing large-scale subsidence
from the building ridge will result in a lull in convective activity
during the first half of the week.

As the aforementioned ridge of high pressure builds over the area,
we will see temperatures increase through the first half of the
week, with above normal temperatures returning during the latter
half of the week. Increasing temperatures will bring increasing
HeatRisk, with widespread Moderate HeatRisk across the region by
Thursday and pockets of Major HeatRisk popping up in Death Valley,
the Colorado River Valley, and the Las Vegas Valley. As ridging
builds over the area, ensemble guidance points at upper-level flow
becoming more southeasterly in northwestern Arizona, which would
open the door for moisture to creep back into the region. However,
uncertainty remains high at this time, so no promises.

&&

.AVIATION...For Harry Reid...For the 06Z Forecast Package...Winds
are expected to remain light and largely follow typical, daily
patterns throughout the TAF period. Threw in a VCSH for Sunday
afternoon in case the decaying remnants of storms drift into the
southwestern valley, but currently thinking convection will stay
southwest of town. Southerly outflow from this activity may reach
the terminal (~25% chance), but probably stays below 25 knots.
Convection wanes is forecast to wane in the evening with calm and
dry conditions overnight. Cloud bases remain at or above 10kft. High
temperature may approach 100F around 22z-01z, but anvil shading will
likely keep us in the upper 90s.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 06Z Forecast Package...Isolated to scattered
convection resumes Sunday afternoon, primarily across Clark, eastern
San Bernardino, and central Mohave counties. Currently thinking
activity will stay out of the Las Vegas, but cannot rule out a few
decaying remnants from storms southwest of town making it into the
valley. Heavy rain and gusty outflow winds likely near any storms.
Convection should wane in the evening hours. Outside of any
convective influences, expecting light winds in most locations. The
exception is the southern Great Basin and Owens valley where breezy
south winds are forecast. Cloud bases remain at or above 10kft.

&&

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

&&

$$

DISCUSSION...Stessman
AVIATION...Woods

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