Twentynine Palms, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

914
FXUS65 KVEF 141209
AFDVEF

Area Forecast Discussion
National Weather Service Las Vegas NV
509 AM PDT Mon Apr 14 2025

.SYNOPSIS...Today through midweek, expect similar temperatures as
Sunday. Late-week, a dynamic weather system moves into the region,
which will increase chances of precipitation, gusty winds, and will
cool off temperatures substantially.

&&

.SHORT TERM...Today and Tuesday.

Through the day today, an upper-level low in the southeastern
Pacific will continue to strengthen. As it does so, a shortwave will
ride counter-clockwise around it, pushing into the Desert Southwest
this evening. Moisture content associated with this shortwave is
modest, with forecast PWATs between 100 and 140% of normal (normal
PWAT this time of year is around 0.30"). Coupled with sub-optimal
PWATs for measurable precipitation, forecast HRRR soundings show a
pronounced inverted-V signature, indicating very dry low-levels. As
such, not expecting widespread measurable precipitation, but this
evening between about 7pm and 12am, a swath of sprinkles will push
northward through the forecast area. Cannot rule out the occasional
bolt of lightning, which would result in locally higher rain rates
as well as erratic, gusty winds from its direction, but overall, not
expecting impacts aside from a ruined car wash.

Otherwise, heights over the region will remain elevated across the
Desert Southwest through mid-week, so temperatures will continue to
range 7 to 10 degrees above seasonal normals, with widespread
"Minor" Heat Risk.

.LONG TERM...Wednesday through Sunday.

A notable pattern change arrives mid/late week as two systems
phase together over our area. On Wednesday, ensemble guidance is
in fairly good agreement with a shortwave moving south out of
western Canada and a cutoff low moving onshore near Point
Conception. As anomalous low-level moisture pools between the two
systems, scattered showers and isolated storms are expected to
develop across the Great Basin and Sierra on Wednesday. On
Thursday and Friday, guidance merges the systems together, forming
a single, closed low over the Great Basin and Mojave Desert. With
lingering low-level moisture and cold air aloft, precipitation
chances continue and spread southward across most of the area.
Latest NBM has PoPs ranging anywhere from 30-50%, with the higher
probabilities across the southern Great Basin. Thunderstorms will
certainly be possible (10-30% chances) with this activity as well.
The cold air aloft will also foster lower snow levels,
particularly if the low moves directly overhead. This should
result in late-season snow accumulations to the Sierra and Spring
Mountains, where there is a ~50% chance of 4"+.

Outside of the precipitation potential, the other main features of
the late-week systems are the gusty winds and cooler temperatures.
Winds are expected to be strongest on Wednesday and Thursday as the
systems approach and begin to phase. Best chances (40-60%) of wind
impacts are across western San Bernardino County, while the rest
of the area ranges from 10-30%. As guidance moves the low overhead
on Friday, winds weaken. This is also when temperatures will be
their coldest. Forecast highs across the area go from 75-90
degrees on Wednesday to 55-75 degrees on Friday, some 10-15
degrees below-normal.

Over the weekend, ensemble guidance has the low advancing eastward,
pushing out of our area. As a result, precipitation chances wane
while temperatures moderate toward seasonal values.

&&

.AVIATION...For Harry Reid...For the 12Z Forecast Package...Light
and variable winds early this morning will settle out of the
northeast by 16Z, increasing to around 10KT, with continued high
clouds streaming over the region. This afternoon, winds will
become light and variable until early evening, when a southerly
wind shift is expected with winds again increasing to around 10KT
with intermittent higher gusts to 15-20KT possible. However, low
to moderate confidence in the occurrence of gusts as well as
precise timing precludes inclusion in the current TAF. These winds
will be coincident with an increase in midlevel clouds as
ceilings lower to around 15kft. After 06Z, winds again become
light as ceilings gradually improve, with winds settling out of
the southeast after daybreak. The only other concern late evening
and overnight will be potential for virga in the vicinity of the
terminal, which could produce brief degradations in ceilings as
well as gusty winds, though the potential for this looks to be
very low at this time.

For the rest of southern Nevada, northwest Arizona and southeast
California...For the 12Z Forecast Package...At KVGT and KHND,
northeasterly winds around 5-8KT are expected through this
afternoon, gradually shifting to the south- southeast through
early evening. After 02-03Z, winds will increase to around 10KT,
before becoming light and variable after 08-09Z. At KBIH will see
traditional diurnal wind patterns, with northwesterly winds
shifting to the south- southeast during the afternoon. Up- valley
gusts to around 17KT are expected before winds become light and
variable after sunset. Winds at KDAG will also follow diurnal
patterns through early afternoon, when winds shift to the east-
southeast and become gusty, with gusts to 20-25KT expected. After
sunset, winds return to the west with gusts expected to diminish
and sustained speeds gradually fall below 10KT by 10Z. For Lower
Colorado River Valley terminals, KEED and KIFP will both see
intermittently gusty north winds this morning, with gusts to
18-20KT expected. Gusts will briefly diminish as winds become
light and variable for a few hours after 18Z, then increasing out
of the south- southeast through early evening, remaining
southeasterly thereafter. An increase in mid and high level clouds
is expected, with ceilings between 10-15kft expected this
afternoon into late evening before gradually improving. KVGT,
KHND, KEED, and KIFP could see virga and potential erratic and
gusty winds during the evening, though confidence is low at this
time.

&&

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

&&

$$

SHORT TERM...Soulat
LONG TERM...Woods
AVIATION...Phillipson

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