Area Forecast Discussion
Issued by NWS Las Vegas, NV

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FXUS65 KVEF 271714
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
914 AM PST Fri Jan 27 2023

.SYNOPSIS...Cool and calm conditions prevail for a few days before
our next system approaches late in the weekend. Gusty south-
southwest winds expected on Sunday, with light precipitation
spreading south Sunday evening and Monday. Minor snow accumulations
possible down to around 3500 feet, particularly in our northern and
eastern locations.

&&

.UPDATE...Expect cool and dry conditions across the area today
with mostly light winds and cool temperatures. A low pressure
trough to our north will sink southward into the area today
bringing a batch of denser mid and high clouds to mainly our
northern zones. Across our southern areas, expect scattered high
clouds by later this afternoon into the evening.

&&

.PREV DISCUSSION...116 AM PST Fri Jan 27 2023...

.SHORT TERM...Today and Saturday.

A rather quiet couple of days are in store as we remain under steady
northwest flow aloft. Guidance shows a weak perturbation passing
through Saturday morning, but other than a few high clouds, this
system doesn`t produce much in terms of sensible weather. With a
more notable shortwave on its heels (which is discussed in the long
term section) and a progressive eastward movement, the pressure
gradients and resulting winds will be weak. Wind gusts are forecast
to be generally in the 10-15 mph range both days. Temperature-wise,
we remain below-normal as most locations top out in the mid 50s and
low 60s.

.LONG TERM...Sunday Night through next Friday.

Through the day on Sunday, a shortwave trough will breakaway from
the longwave trough that has dominated the weather pattern this
week. Ensembles indicate that this shortwave will dig along the
state of California before closing off over southern California late
Sunday night into Monday morning before pushing eastward through our
forecast area. In general, this trajectory looks to be that of an
`inside slider`, with little moisture associated with it. Gusty
southwest winds will pick up ahead of it on Sunday, with breezy
northwest winds behind it on Monday.

However, the 00Z run of the deterministic GFS indicates a further
west trajectory, with the area of low pressure closing off over the
southeastern Pacific Ocean before moving inland over our area.
Should this happen, there will be more available moisture to tap
into, with PoPs and QPF across likely trending upward (though, an
increase in snow levels would also be possible). Granted, this is a
deterministic model run, so take it with a grain of salt. That said,
comparing the 00Z run of the GFS ensemble mean with yesterday`s 00Z
GFS ensemble mean, there is a substantial westward shift, with
higher QPF values and lower snow total values. Low confidence in the
details, but in general, not anticipating high precipitation values
regardless, due to an area of high pressure over the Pacific Ocean
blocking tropical moisture from approaching the western United
States coast.

It is possible that light accumulations on Interstate 15 through
Mountain Pass and Interstate 40 east of Kingman could result in
impacts with this system, but we will continue to assess snow levels
and moisture amounts as we approach the higher-resolution domain.

Temperatures Tuesday and Wednesday morning will approach freezing in
the Las Vegas Valley, with sub-freezing temperatures expected across
the southern Great Basin and Owens Valley. As this system moves
eastward out of our area, ridging will briefly set up, allowing
temperatures to increase, but will still remain 3-5 degrees below
seasonal averages heading into next weekend.

&&

.AVIATION...For Harry Reid...Winds becoming light and
variable this morning. Afterwards, winds begin to follow a diurnal
pattern and shift to the east late morning through the afternoon,
likely remaining 8 kts or less. Winds begin to establish a more
southwesterly direction tonight. A band of high clouds will sag
south across the area today and tonight, dissipating Saturday
morning.

For the rest of southern Nevada, northwest Arizona and southeast
California...North winds 8-12 kts this morning within the lower
Colorado River Valley will subside this afternoon. Elsewhere, winds
will generally follow a diurnal pattern. Speeds should be 10 knots
or less. A band of high clouds will sag south across the area today
and tonight, dissipating Saturday morning.

&&

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

&&

$$

UPDATE...Salmen

SHORT TERM...Woods
LONG TERM...Varian
AVIATION...Pierce

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


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