Twentynine Palms, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

210
FXUS65 KVEF 230255 AAA
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
655 PM PST Fri Nov 22 2024

.SYNOPSIS...Dry and warming conditions are expected for most areas
through Saturday. An approaching system will spread high elevation
snow across the Sierra and gusty winds across the Mojave Desert
tonight through Saturday night. Another system will move across
the region through the first half of next week, resulting in
chances for widespread rain and mountain snow.

&&

.UPDATE...

A Wind Advisory went into effect at 4 PM for the Eastern Sierra
Slopes and Owens Valley with observations showing a sharp uptick in
winds over the last couple of hours with the highest gust so far 61
mph in Round Valley. Winds will continue to increase through the day
Saturday as the jet streak sags into the region. A High Wind Warning
goes into effect at 1 AM Saturday for the Spring Mountains, a Wind
Advisory goes into effect at 1 AM Saturday for the Las Vegas Valley
and at 10 AM Saturday for Western Clark and Southern Nye Counties.
All wind products are set to expire at 4 AM Sunday as the pressure
gradient relaxes. A Winter Weather Advisory also went into effect at
4 PM for the Eastern Sierra Slopes and is also set to expire at 4 AM
Sunday. Both wind and winter weather conditions will result in
difficult driving conditions so be sure to use extra caution and
allow extra time if traveling this weekend. The forecast remains on
track with no updates needed at this time.

&&

.PREV DISCUSSION...125 PM PST Fri Nov 22 2024
.SHORT TERM...Tonight through Sunday Night.

Dry conditions are solidly in place across the region this
afternoon. A stream of high clouds is gradually shifting south
across the southern Great Basin as a weakening atmospheric river
(AR) slides south through western California. A 140-150 kt jet
associated with the large-scale trough will being to impinge upon
the Sierra this evening and gradually work its way south and
weaken to around 110-120 kt by Saturday night. This will help set
the stage for very strong ridgetop winds and the potential for a
moderate downslope wind event both in the Sierra into the Owens
Valley as well as across the Spring Mountains into Red Rock Canyon
and potentially the far western Las Vegas Valley. Confidence in
impacts is slightly lower in the Sierra/Owens Valley given the
coincidence of the potential wind with high elevation
precipitation which tends to disrupt downsloping events. For the
moment, have opted is issue a Wind Advisory for that area (along
with the existing Winter Weather Advisory for elevations above
7000 ft). Winds do have the potential to reach US-395, but it
appears those probabilities are generally 20-30%. For the Springs,
the Wind Advisory was upgraded to a High Wind Warning given the
chances for gusts in excess of 58 mph have increased above 50% for
much of the northern/eastern slopes. Also issued a Wind Advisory
for the Las Vegas Valley, primarily for the far western portions
of the Valley. For the central/eastern portions of the Valley,
peak gusts are likely be remain between 30-40 mph Saturday
afternoon/evening.

Precipitation chances for Saturday night into Sunday continue to
dwindle with chances in the Las Vegas Valley now falling below 10%
with this first round. The main chances for precipitation will be
across the southern Great Basin areas of Nye and Lincoln
counties. Winds will decrease by Sunday morning and highs Sunday
will be 5-10 degrees cooler than Saturday.

.LONG TERM...Monday through Thursday.

Confidence in the details of the forecast begins to wane during
the first half of next week. The latest cluster analysis continues
to show a range of potential synoptic evolutions. The favored
solutions is a relatively quick shift of the trough eastward
across the region Monday-Tuesday. However, there remains a 10-30%
chance of a slow progression that extends precipitation chances
into the middle of the week. In any case, as this system moves
through, precipitation chances will spread across the region. Snow
in the Sierra could be on the order of 1-2 feet and a Winter
Storm Watch was issued for a fairly broad period of time given the
continued uncertainty in the timing. By the latter half of next
week, generally dry conditions under cool northwest flow are
favored.

&&

.AVIATION...For Harry Reid...Winds will remain under 10 knots and
will follow typical diurnal directional trends through early
Saturday morning. Winds will pick up and become more southerly early
Saturday morning. Winds will continue to increase in speed
throughout the day on Saturday, with wind direction gradually
shifting back to the southwest by late Saturday morning/early
Saturday afternoon. Wind gusts are expected to top out in the 25 to
35 knot range.

For the rest of southern Nevada, northwest Arizona and southeast
California...Winds at the remaining Las Vegas Valley TAF sites will
remain light, following typical diurnal directional trends through
early Saturday morning when winds will increase in magnitude and
become more southerly to southeasterly. These winds will continue to
increase as they gradually swing around to the southwest. These wind
gusts will top out in the 25 to 35 knot range. Winds at KDAG will
remain under 10 knots and will follow typical diurnal directional
trends with a brief period of light and variable winds as they
transition. Light northerly winds will become light and variable
this evening at KIFP. These light and variable winds will continue
through the overnight hours before picking up and swinging around to
the southeast on Saturday morning. KEED will see light and variable
winds settle in from the west this evening. These light westerly
winds will continue through the overnight hours before picking up
and swinging around to the southeast on Saturday morning. KBIH will
see 8 to 12 knot southeasterly winds increase in magnitude early
this evening. These 20 to 25 knot southeasterly wind gusts will drop
off during the overnight hours as showers develop in the Eastern
Sierra. Winds will continue to maintain a more southeasterly
direction through the overnight hours with the potential for light
rain to impact the terminal area between 10 to 16 UTC. 8 kft CIGS
are expected to accompany any showers that impact the terminal.
Precipitation chances for KBIH will decrease on Saturday morning as
winds swing around to the north.

&&

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

&&

$$

DISCUSSION...Wolcott
AVIATION...Stessman

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