West Puente Valley, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

110
FXUS66 KLOX 120003
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
503 PM PDT Fri Apr 11 2025

.SYNOPSIS...11/1236 PM.

After another warm day today, a cooling trend will establish over
the weekend and into early next week as onshore flow strengthens.
Night through morning low clouds will become a staple of the
forecast over the weekend, pushing into the valleys by early next
week and into coastal slopes by mid week.

&&

.SHORT TERM (TDY-MON)...11/213 PM.

Fairly benign weather on tap as we move forward into the weekend.
Temperatures today will continue to be in the 70s to 80s across
the majority of the region, with a few locations pushing into the
low 90s. Increasing onshore flow today and decreasing 500 mb
heights will help establish a cooling trend into this weekend,
with high temps falling by up to 8 degrees Saturday compared to
today, and Sunday high temps falling a few degrees more.
Temperatures will be generally in the 60s at the coast, and 70s to
80s away from the beaches, which is still 5 to 10 degrees above
normal for this time of year (except towards the coast where temps
will be near normal).

A little bit of uncertainty with the marine layer clouds tonight
and into the weekend. While the forecast leans toward the HREF and
NAM, with low clouds and fog becoming more expansive over the
weekend thanks to the increasing onshore flow, other model
guidance suggests low clouds, if any, stick to the immediate
coasts of the Central Coast and L.A. County coasts. As low clouds
are pushing into the Santa Monica Basin as of now, and a decent
eddy has formed, decided to stick with the more expansive marine
layer clouds. As 500 mb heights continue to decrease over the
weekend ahead of a trough moving over the area, low clouds and fog
are likely to push into the coastal valleys by Saturday night. The
onshore flow will lead to clouds struggling to clear from the
beaches during the morning hours, and may continue to hug the
beaches through the day. Besides the low cloud and fog potential,
some higher level clouds are expected to stream over the region
at times through the weekend, mainly today and Saturday.

.LONG TERM (TUE-FRI)...11/212 PM.

Cooler temperatures are still favored for next week, especially
compared to these past few days as a series of cutoff upper level
troughs will move over the region through the week. As of now,
deterministic models and ensembles are leaning toward very minimal
precipitation for these systems moving through.

For the first system, the forceast leans towards a deeper marine
layer with cooler temperatures, however some light night through
morning drizzle or mountain showers cannot be ruled out. Between
the deterministic runs of the GFS and the first few hours of the
system with the NAM, the placement of this system shows upper
level diffluence over the area, some localized vorticity lobes,
and some higher level moisture. In other words, this system has
some instability and has about a 5 percent chance of bringing
isolated thunderstorms (dry lightning) and showers to the
mountains sometime Monday into Monday night. However, this outcome
heavily relies on the timing and exact track of the system, so
these shower chances could increase, or decrease, as we get closer
to Monday.

Looking at the next event, there continues to be differences in
the deterministic runs for when a cutoff upper level low pressure
system will move into the region. The Long Range Ensemble
Forecast (LREF) clusters favor the cutoff trough, but potentially
strong enough to bring some showers (and rain totals less than 0.5
inches) to the region. While the EC deterministic run is showing
potential for showers, only about 20 percent of its ensemble
members show any rain, and even then the timing of each is
scattered from as early as Wednesday night to as late as over the
following weekend. The GFS deterministic, on the other hand,
leans toward no precipitation, however its ensembles are similar
to the EC`s. Regardless, a much cooler airmass will move over the
region, and periods of high clouds will be possible along with the
troughs. Some rain may be possible across the region toward the
latter half of the week, but as of right now, is leaning toward
lesser totals (under an inch). Forecast values go with NBM
solutions for now.

&&

.AVIATION...12/0002Z.

At 2228Z at KLAX, the marine layer was around 400 feet deep. The
top of the inversion was near 1700 ft with a temp of 23 C.

Overall, moderate confidence in 00Z TAF Package. High confidence
in VFR conds for desert airfields (KPMD, KWJF) thru fcst pd. There
is a 15% chance of VLIFR to LIFR conds at KBUR and KVNY from 10Z
to 16Z Sat. There is a 30% chance of LIFR conds at KSMX from 08Z
to 15Z Sat.

There is a 30% chance of LIFR/IFR cig arrival at KSBA from
12Z to 18Z Sat. There is a 30% chance of LIFR conds at KOXR from
10Z to 17Z Sat - lower chances (10-20%) at KCMA. 30% chance of
LIFR conds at KSMO and slightly higher at KLGB.

Timing of cig/vsby restrictions may be off +/- 3 hours. Flight
cats may be off one or two.

KLAX...Moderate to low confidence in 00Z TAF. Arrival and
departure of cigs may be off by a couple of hours. There is a 30%
chance of LIFR conds (<3SM,