Moapa Valley, Nevada 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

487
FXUS65 KVEF 231727
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
927 AM PST Mon Dec 23 2024

.SYNOPSIS...Fair weather is expected for Monday with continued
high cloud cover. A weather system will move in Christmas Eve and
spread snow into the Sierra and Spring Mountains and shower
activity into the Mojave Desert and southern Great Basin Tuesday
evening. Gusty winds will develop across much of the area as well,
particularly across western Nevada and the Western Mojave Deserts
in California. Calmer conditions will resume for Christmas Day
with temperatures returning closer to normal.

&&

.UPDATE...Quiet conditions prevail for one more day before our next
system arrives Christmas Eve. Winds and precipitation chances will
increase during the afternoon and evening hours across the area.
Locations west of Las Vegas have the best shot of seeing wind
impacts, with Wind Advisories in effect Tuesday and Tuesday night.
Precipitation impacts should be limited to elevations above 7000` in
the Spring Mountains, where a Winter Weather Advisory is in effect
from 4PM Tuesday to 4AM Wednesday. Total snowfall of 3 to 6 inches
is expected. Snowfall rates may become heavy at times, with a 50%
chance of 1"/hr and ~20% of 2"/hr rates in upper Kyle/Lee Canyons.
Use caution if you have travel plans in the Spring Mountains
Christmas Eve! Precipitation chances wane by Wednesday afternoon,
leaving most of the area with a breezy but seasonal Christmas Day. A
secondary, weak system moves through on Thursday, bringing some light
precipitation chances to our northern and eastern areas. Beyond
that, the forecast looks pretty dry and mild.

&&

.SHORT TERM...through Christmas Day.

Progressive ridge axis will build across the region today making
for one more day of pleasant conditions before a more dramatic
change moves in on Tuesday. While cloud cover today will be
considerably less than on Sunday, there will still be some
transient high clouds spreading eastward through the day. A
potent shortwave trough will make its approach on Tuesday, with
snow showers spreading into the Sierra during the morning hours.
As the trough edges closer, gusty winds will spread across the
Mojave Desert and southern Great Basin in the afternoon and
evening hours, impacting mainly western Nevada and our California
Desert zones. A wind advisory was issued for these areas to
account for the wind impacts, which may impact travel along busy
transit corridors including I-15, US-395, and US-95 between Las
Vegas and Tonopah.

As the shortwave advances through the Great Basin Tuesday evening,
shower activity will spread across our southern Great Basin zones,
with lesser chances dragging across the Mojave Desert. Pocket of
cold air aloft associated with the core of the shortwave, with
500mb temps of -22C, will drop through southern Nevada, and may
promote a brief window of opportunity for a few lightning strikes
in the evening with the heavier shower activity that develops,
especially across the southern Great Basin zones north of Las
Vegas. Precipitation chances continue to increase, though our
window of opportunity remains very brief for precipitation, and
chances decrease quickly from north to south across our forecast
area. Precipitation expectations across most desert locations
remain very light, with a tenth of an inch of less favored.
Despite the light totals, any rain that falls will result in very
slick roadways after the long dry spell.

In the Spring Mountains, those hoping for a White Christmas may be
in luck, with a 6-9 hour window for accumulating snow Christmas
eve into early Christmas morning in the Lee and Kyle Canyon areas.
Snow levels through the day Christmas eve will generally be above
8000 feet, limiting totals during the day, but with nightfall
snow levels will drop as colder air invades the region. Latest NBM
Probabilities suggest 60 percent chances of 4 inch or more snow
totals in Lee Canyon, around 30 percent chance for 4 inches in
Kyle Canyon. Went ahead and issued a Winter Weather Advisory for
this potential. With steep lapse rates and some marginal
instability at least briefly present, precipitation type may mix
with graupel at times as well, resulting in especially slick
roadways.

Shortwave will push east Christmas day with dry conditions
resuming and calmer conditions. Temperatures will cool closer to
seasonal normals, although still will top out a few degrees warmer
than typical for Christmas day.

.LONG TERM....Thursday through the Weekend.

Another shortwave is progged to zip through the region Thursday into
Friday as a piece of energy breaks off from a trough sitting off the
Pacific Northwest coast. Models continue to favor a scenario that
would result in limited precipitation impacts with limited moisture
available for precipitation to develop. Low chances for light
precipitation currently highlight the terrain in the Sierra and
northern Lincoln County, which would make sense given the overall
set up. Even if this changes and more areas could see precipitation,
not expecting anything more than light precipitation. A response
from the winds as the wave moves through is also possible, however
the system is not overly strong or have a significant pressure or
temperature gradient associated with it. Nothing suggested a
significant wind event with this system as it is not overly powerful
or will be over the area long enough for winds to do much even if
they pick up enough to cause isolated impacts. Current probabilities
on long range ensembles for impactful wind gusts over 40 MPH remain
low (30% or less).

Ridging will build in again behind the exiting system this weekend.
After a period of near normal temperatures, the returning ridge will
warm temperature back above normal.

&&

.AVIATION...For Harry Reid...Light winds under 8KT following
mainly diurnal wind patterns are expected through early Tuesday
afternoon. An approaching storm system will result in an increase in
southwesterly winds late Tuesday afternoon into Tuesday evening,
though there remains uncertainty in the timing and magnitude of
these winds. Mid and high clouds with bases around 10-20kft AGL will
continue streaming over the region, SCT this morning and becoming
BKN-OVC tonight through Tuesday. There is a medium to high
probability (60-80%) of measurable precipitation at the airport
Tuesday afternoon and evening, but rainfall, should it occur, will
remain light with minimal impacts.

For the rest of southern Nevada, northwest Arizona and southeast
California...Light winds following diurnal wind patterns are
expected across the region through Tuesday morning. The exception
today will be KIFP, where northerly winds become elevated by mid-
morning with sustained speeds around 12-15KT. Otherwise, VFR
conditions prevail, with passing mid and high clouds with bases
around 10-20kft AGL.

&&

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

&&

$$

UPDATE...Woods
SHORT TERM...Outler
LONG TERM...Nickerson
AVIATION...Phillipson

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