510
FXUS65 KVEF 051909
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1209 PM PDT Thu Jun 5 2025

.SYNOPSIS...Isolated-to-scattered showers and thunderstorms are
expected across southern Nevada and northwest Arizona this afternoon
with lesser chances in southeastern California. Gusty outflow winds,
frequent lightning, small hail, and moderate-to-heavy rain will be
threats with any storms that develop. Additional weaker storms are
possible tomorrow. Things will begin to dry out and heat up as we
head into the weekend.

&&

.SHORT TERM...Today through Friday.

An elongated positively tilted 500 mb trough will move east through
the forecast area today. Increased vorticity advection combined with
plentiful moisture (PWATs 100 to 200 percent of average) and daytime
surface heating has already led to thunderstorm development over
Mohave County and parts of southern Nevada as of 12 PM PDT. The
strongest storms over far southern Clark County feature cloud tops
above 30,000 feet and are producing heavy rainfall and frequent
lightning. Hail and strong outflow winds are possible with any
storms today, but weaker shear should result in smaller hail
compared to earlier this week. Guidance shows storms becoming more
numerous through the day as instability increases with surface
heating. Convection should taper off tonight as surface heating ends
and atmospheric instability is exhausted by storm activity.

Although moisture and instability decrease tomorrow, there should be
enough left for some isolated storm development in the afternoon.
SBCAPE values fall to 500 J/kg or less with PWATs still around 200
percent in some areas. Storm activity will primarily be over high
terrain where lift is the greatest. Outside of storms, temperatures
return to near average temperatures for early June, which for Las
Vegas means highs in the mid 90s.

.LONG TERM...Saturday through Wednesday.

A return to more typical early June hot and dry conditions is on
tap for southern Nevada, southeastern California and northwestern
Arizona starting this weekend. Ensemble guidance and cluster
analyses remain in good agreement regarding a strengthening ridge
over the region, which will facilitate a decrease in moisture and
gradually warming temperatures, warming to well above normal
Sunday through at least Tuesday. Fairly widespread highs in the
90s and lower 100s are expected Sunday through Tuesday, with
Monday and Tuesday looking to be the hottest days of the forecast.
Along with the warming temperatures will be increasing HeatRisk,
with "Major" HeatRisk returning to Death Valley and the Lower
Colorado River Valley on Saturday, gradually expanding across
other lower elevations through early next week, with "Extreme"
HeatRisk possible for the lowest Valleys Monday and Tuesday.
Thereafter, ensemble members begin to diverge, with some
indications that a weak trough may try to undercut the ridge
heading into midweek, but with little in the way of moisture, this
trough would have little impact other than tempering the hot
temperatures by a couple of degrees, and producing some breezy
conditions. Stay tuned.

&&

.AVIATION...For Harry Reid...For the 18Z Forecast
Package...Convection will develop today and is expected to be more
widespread than yesterday and may impact all terminals.
Thunderstorms in and around the valley could produce gusty erratic
winds with gusts over 30KT, especially between 20Z and 02Z. In
addition- storms today could produce lightning, small hail, moderate
to heavy that could reduce visibility to 6sm, and CIGs to 8000ft.
Outside of convection influence, southeast winds are expected this
afternoon around 8KT with intermittent gusts to around 15KT.

Precipitation will diminish after 03Z this evening. Winds may be
erratic for a few hours after thunderstorms end depending on how
outflow impact the valley this afternoon, but diurnal winds trends
with light winds speeds are expected to set up by 08Z at the latest.
Light winds following typical trends will then persist through the
rest of the TAF period. On Friday, isolated showers and
thunderstorms may develop after 20Z but the chance for convection
and convective impacts is much lower on Friday compared to today. It
is less likely that gusty outflows will impact the valley on Friday
with the most likely scenario being light diurnal wind trends
continuing through the afternoon.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Scattered showers and
thunderstorms will develop this afternoon in Clark, Lincoln, and
northern Mohave counties, as well as in the Sierra. Convection today
could produce erratic wind gusts over 30KT, moderate to heavy rain,
reduced visibility due to heavy rain or blowing dust, lightning, and
CIGS below 10kft. Precipitation will diminish after 03Z, with dry
conditions expected across the region by 08Z. After a dry night,
additional showers and thunderstorms should develop after 18Z on
Friday in southern Nevada and western Arizona, however convection on
Friday will be less widespread and less likely to produce impacts
compared to today.

Outside of convective influence, expected south to southwest winds
around 10KT to develop this afternoon across the region with the
strongest winds expected in the Colorado River Valley where gusts up
to 20KT are likely. Winds will diminish after sunset with typical
light wind patterns expected tonight and Friday.

&&

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

&&

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

&&

$$

SHORT TERM...Meltzer
LONG TERM...Phillipson
AVIATION...Nickerson

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