446
FXUS65 KVEF 120901
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
201 AM PDT Wed Jun 12 2024

.SYNOPSIS...Hot and dry conditions continue today followed by
slight relief Thursday as a weak low pressure system moves in from
Southern California, but well above normal temperatures will persist
through Saturday. A more noticable cooldown and increased winds are
likely Sunday into early next week as a broad trough drops down from
the Pacific Northwest.
&&

.SHORT TERM...Today through Saturday.

The ridge over the Desert Southwest will provide another hot day
with highs this afternoon within a degree or two of those observed
Tuesday. The Excessive Heat Warning remains in effect for parts of
Mohave, Clark, southern Nye and Inyo counties until 9 PM this
evening.

The cutoff low spinning southwest of San Diego was devoid of clouds,
but could be seen on water vapor imagery and there was moisture
between Acapulco and Cabo San Lucas that was working its way toward
northwest Mexico and will be pulled up into western Arizona Thursday
on the leading edge of the low as it begins to move into Southern
California. The latest HREF and NBM indicate a fairly stable air
mass over Mohave County and not much potential for thunderstorms.
However, the incoming mid-level moisture will lead to favorable
conditions for gusty winds associated with any virga or light
shower. The HREF indicates a 30-50% percent chance of convective
gusts over 35 mph for eastern Mohave County Thursday afternoon.
Can`t completely rule out the possibility of a thunderstorm, but the
probability is less than 10 percent and not enough to mention in the
forecast for now. The rest of the region will remain dry with
temperatures lowering 2-4 degrees and afternoon south winds gusting
20-25 mph.

The upper low is forecast to be centered over northwest Arizona
early Friday morning and will lift across the Four Corners Region by
Friday afternoon leaving dry conditions across our region as a
shortwave ridge redevelops over the Desert Southwest going into
Saturday. This will allow temperatures to rebound a few degrees and
lead to elevated HeatRisk before a significant cooling trend begins
Sunday.

.LONG TERM...Sunday through next Wednesday.

Some clarity is starting to show itself in the long range forecast
or next week as models try to resolve an upper level trough digging
into the region early next week. Models have come into some
consensus in the past 24 hours that a deepening trough will dig
south into the Southwest US by Monday, though there continues to be
uncertainty in exact strength and how far it will dig. Impactful
precipitation is not anticipated as the general trajectory on all
possible solutions is dry.

While there is still a decent temperature spread noted on high
temperature possibilities early next week-increasing confidence that
Monday and Tuesday will be cooler than what we have been
experiencing. There is a 50% chance the high temperature in Las
Vegas doesn`t reach 100F Monday through Wednesday next week.

Winds will be the other thing to watch. Exact wind impacts will
depend on the depth of the incoming low, increasing winds are likely
based on many of the long range model camps but how strong they will
get will depend on how deep and how far south the trough can get.
NBM 1D viewer probabilities for impactful winds gusts have increased
to around 40% in areas that are prone to west or southwest winds
like Barstow, CA. It`s worth noting- there continues to be some
impactful wind gust members on ECMWF Ensemble meteograms. ECMWF EFI
plots suggest Monday has the best potential for impactful winds with
smatterings of highlighted areas for higher than normal winds.
&&

.AVIATION...For Harry Reid...Winds through the morning hours will be
predominantly light and follow typical diurnal trends. Expect a
southerly component to the wind direction this afternoon, initially
favoring a southeast component before becoming predominantly
southwest late in the afternoon through sunset. Wind speeds
generally under 8 knots this morning becoming 10-12 knots this
afternoon with gusts around 20 knots. Clear skies.

For the rest of southern Nevada, northwest Arizona and southeast
California...Light and diurnal winds anticipated at all of the area
TAF sites through this morning then becoming gusty 20-25 knots this
afternoon through sunset before gustiness ends. FEW mid-high clouds
at KBIH this afternoon otherwise clear skies.

&&

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

&&

$$

SHORT TERM...Adair
LONG TERM...Nickerson
AVIATION...Salmen

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