Shell Beach, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

380
FXUS66 KLOX 112113
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
213 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...11/1735Z.

At 1722Z at KLAX, the marine layer was around 250 feet deep. The
top of the inversion was near 2500 ft with a temp of 22 C.

High confidence in VFR TAFs for KPRB, KSBP, KSBA, KPMD, AND KWJF.
High confidence in remaining sites through 06Z.

Moderate confidence in TAFs after 10Z for KBUR and KVNY. There is
a 10-20% chance for VLIFR to IFR conds from 12Z to 16Z with
higher chances at KBUR, but low confidence on minimum flight cat
if cigs arrive.

Low confidence in remaining sites after 06Z. There is a chance
for VFR conds to prevail through the period at KOXR (30%), KCMA
(40%), KSMO (30%), KLAX (30%), and KLGB (10%). Otherwise, flight
cat changes may be off +/- 4 hours and minimum flight cat may be
off by at least one cat at any time.

KLAX...Low confidence in the 18Z TAF after 06Z. Arrival of cigs
may be off +/- 4 hours. Low confidence in minimum flight cat, but
there is a 40% chance cigs could be BKN002-005 and/or vsbys
1SM-3SM once cigs arrive. There is a 30% chance VFR conds
prevail. No significant east wind component expected.

KBUR...High confidence in 18Z TAF through 10Z, then moderate
confidence thereafter. 20% chance for VLIFR to IFR conds from 12Z
to 16Z, and a 10% chance for VLIFR. Low confidence in minimum
flight cat.

&&

.MARINE...11/143 PM.

In the outer waters, there is a 50-60% chance GALE force winds
will become more widespread in the northern and central zone
(PZZ670/673) this afternoon and will continue in these areas much
of the time thru late tonight. Due to lack of upper level wind
support and model guidance backing off winds for Sat, the GALE
WARNING was shortened to continue through late tonight instead of
Sat evening. Then, Small Craft Advisory (SCA) level winds (and
local gusts to 35 kts at times) are expected late tonight thru
Sun morning and SCA level seas will begin late this afternoon and
continue into Sun evening. In the southern zone (PZZ676), SCA
level winds will continue thru Sun morning, with seas likely
staying at SCA levels thru Sun evening. There is a 30% chance of
Gale force wind gusts during the afternoon/eve hours today and
Sat. SCA conds are not expected Sun night thru Tue night.

In the inner waters N of Pt Conception, SCA level winds will
likely (60-80% chance) persist from this afternoon through Sun,
with highest chances in the afternoon thru late eve hours. SCA
conds will likely continue thru late Sat eve. SCA level seas are
also expected from late tonight through Sun. There is a 30% chance
of Gale force winds during the afternoon/eve hours today and a
lower chance Sat. SCA conds are not expected Sun thru Tue night.

In the Santa Barbara Channel, SCA level winds are likely (60-70%
chance) in western portions during the afternoon/eve hours today
and Sat, with a 40% chance of SCA winds pushing eastern portions
Sat. SCA conds are not expected Sun thru Tue night.

In the southern inner waters, there is a 20% chance of SCA level
wind gusts during the afternoon/eve hours Sat from Anacapa Island
to Malibu. Otherwise, SCA conds are not expected thru Tue night.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Sunday for zone
      645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Saturday for zones
      670-673. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zone 673. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT Sunday for zone
      676. (See LAXMWWLOX).

&&

$$

PUBLIC...Lund
AVIATION...Lewis
MARINE...Lewis
SYNOPSIS...Hall/KL

weather.gov/losangeles

Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox