993
FXUS65 KVEF 212008
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
1208 PM PST Fri Feb 21 2025

.SYNOPSIS...Breezy northerly winds will diminish this evening,
with light winds expected areawide this weekend. High pressure
will bring unseasonably warm temperatures to the area this weekend
into next week. A potential weak shortwave may bring increased
winds a low impact precipitation late next week, however
uncertainty is high with the strength of this system. &&

.SHORT TERM....Tonight through Sunday Night.

Ridging will build into the region through the weekend behind the
exiting shortwave to the east. On Saturday as heights build, a weak
piece of energy will zip through the mean flow. This wave wont do
much as the ridge should be the dominate feature, however breezy
winds may develop in the Colorado River Valley Saturday
afternoon. Even with this impulse, winds tomorrow afternoon will
be lighter than today with north winds gusting 20-25 MPH at most,
Probabilities for impactful winds gusts are 20% at most on
Saturday in the Colorado River Valley, so overall not expecting
wind impacts as the rest of the region will see light winds. On
Sunday, heights will continue to build and light winds are
expected areawide.

In response to the building ridge, temperatures will warm each day
this weekend. High temperatures on Saturday will run about 5 degrees
above normal, and by Sunday could be 8-10 degrees above normal for
most locations.


.LONG TERM...Monday through Thursday.

Monday night into Tuesday, a weak shortwave will move into the
Pacific Northwest and Great Basin Desert, which will result in a
slight dampening to the upper-level ridge across the Great Basin.
Though this would typically result in a temperature decrease, the
increased pressure gradients will elevate wind speeds enough to
facilitate atmospheric mixing and allow Tuesday to observe the
hottest temperatures of the week. Ridging will rebuild over the
region Wednesday and Thursday, though heights will range 4-6 mb
lower than earlier in the week. As a result, temperatures will
remain well-above normal, but will decrease slightly through the
remainder of the week.

Expect "Minor" HeatRisk in desert valleys through the long term
forecast period including areas such as the Las Vegas Valley, Moapa
Valley, Colorado River Valley, Morongo Basin, Pahrump Valley, and
Death Valley. Minor HeatRisk affects primarily those individuals
extremely sensitive to heat, especially when outdoors without
effective cooling and/or adequate hydration.

The extended forecast reintroduces PoPs to the region late-week,
though uncertainty is very high at this time. Ensemble means
indicate that a closed low will push into the region from the
eastern Pacific, which will erode the upper-level ridge in place
over the Desert Southwest and usher in modest moisture. At the
moment, it looks as though the bulk of the moisture hits the
windward side of the Sierra Nevada, though the deterministic ECMWF
Integrated Water Vapor (IVT) hints at an interesting southwesterly
moisture trajectory, which would bode well for Mojave Desert
precipitation. Will continue to watch how this unfolds as we get
closer, as this event is at the tail-end of our forecast period.
&&

.AVIATION...For Harry Reid...For the 18Z Forecast
Package...Northeast winds are expected to remain in place through
the afternoon with speeds around 10 kts. It is possible that winds
could shift back to the northwest to north (340-010) during the
afternoon, but if that occurs it will be brief. Around sunset, winds
should become light and stay that way through mid morning Saturday.
No operationally significant clouds or weather expected.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 18Z Forecast Package...Northerly winds can be
expected areawide through this afternoon, with the strongest gusts
of 30 to 40 knots expected in the Colorado River Valley. Winds will
decrease tonight and Saturday, with lingering gusts near 25 knots
possible near KIFP Saturday. No operationally significant clouds or
weather expected.
&&

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

&&

$$

SHORT TERM...Nickerson
LONG TERM...Soulat
AVIATION...Gorelow

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