Llano, California 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

007
FXUS66 KLOX 091623
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
923 AM PDT Wed Apr 9 2025

.SYNOPSIS...09/913 AM.

A gradual warming trend will continue into Thursday as high
pressure aloft builds over the region. Mostly sunny skies will
continue except for patchy night through morning low clouds and
fog at the coast. Daytime high temperatures will be well above
normal temperatures away from the coast through Friday. Onshore
flow should return for the upcoming weekend and bring a cooling
trend into early next week.

&&

.SHORT TERM (TDY-FRI)...09/923 AM.

***UPDATE***

The 24hour temperature change map shows most areas trending warmer
this morning, mostly in the 3-6 degree range, but some areas as
much as 8-12 degrees warmer. So everything looks on track for the
expected warming this week, especially away from the immediate
coast. Coastal fog has been confined to the San Pedro Channel
south. However, hi res models are indicating a 60-70% chance of
the fog expanding north tonight as far as KSBA and possibly down
the Central Coast from the Bay area as well, though lower
confidence in the latter.

***From Previous Discussion***

The latest water vapor imagery shows high pressure aloft
continuing to amplify and build into the region this morning.
Mostly clear skies prevail across the area, except for patchy low
clouds and fog in the Santa Ynez River valley and off the Los
Angeles County beaches. A warming trend will develop today as 950
mb temperatures warm by a few degrees and 500 mb heights climb.
Some weakening of the onshore flow is taking place, but onshore
flow will still remain in place and keep the air mass from getting
excessively hot. Temperatures will still be well above normal
away from the coast today and Thursday, but closer to the coast,
the temperature trends will be much more moderated. With the
latest model solutions suggest onshore pressure gradients not
changing much and most of the change happening in the synoptic
pattern, some tweaks were made to temperatures to reel back some
of the warming along the coast.

The forecast for low clouds and fog will be a little tougher over
the next couple of days. While the deterministic and high-
resolution multi-model ensembles advertise the low cloud field to
remain in place, EPS and GEFS ensemble members keep low clouds to
a minimum through Friday. So far, high-resolution multi-model
ensemble members have performed poorly with the low cloud field
this morning, and the EPS cloud cover means may offer the best
forecast over the coming days. The forecast has been trended
toward a sunnier day today, but there is still a moderate chance
that a late formation and surge of low clouds could develop along
the coast.

EPS and GEFS forecast members still lean toward Friday being the
warmest day. Some of the parameters are a little out of whack as
cloud cover means increase and the overall synoptic pattern
suggests the ridge axis being east of the region. Southwest flow
aloft in place by early Friday morning, will increase through the
day and 500 mb heights will start to fall. To keep the air mass
warmer, the only thing that could happen is the 500 mb high could
build additionally to the east and expand higher heights westward.
Future shifts will need to keep an eye on this development.

.LONG TERM (SAT-TUE)...09/435 AM.

A cooling trend will definitely be underway for the weekend and
possibly into early next week. EPS and GEFS ensemble members
suggest height falls occurring into Sunday, and potentially into
Monday as upper-level troughing replaces the ridging. Cluster
analysis keeps a broader trough in place over the region into
midweek next week. While there is still a lot of uncertainty is
how strong the trough will be, good agreement exists for cooler
temperatures into early next week. Stronger onshore flow and a
deeper marine intrusion should be expected.

&&

.AVIATION...09/1310Z.

At 12Z at KLAX, the marine layer was about 400 feet deep. The top
of the inversion was near 1600 ft with a temp of 19C.

Low clouds and fog were affecting southern portions of the both
the Central Coast and Santa Ynez Valley, and southern portions of
the L.A. County Coast. Conds were mostly LIFR to VLIFR. Cigs
should dissipate by mid morning, then VFR conds are expected thru
this evening. Areas of low clouds and fog with IFR to LIFR conds
are expected on the L.A. County Coast, and possibly the Ventura
County Coast late tonight.

KLAX...Fairly high confidence in the 12Z TAF. There is a 10-20%
chance of IFR cigs from 15Z-17Z this morning. There is a 20%
chance that IFR to LIFR cigs tonight may arrive as early as 08Z.
Any east wind component should remain below 7 kt thru the pd.

KBUR...High confidence in the 12Z TAF with VFR conds thru the pd.

&&

.MARINE...09/809 AM.

In the outer waters, Small Craft Advisory (SCA) winds (21+ kt)
and/or seas (10+ ft) are expected to continue for much of the time
in the northern two zones (PZZ670/673) thru Sun evening. In the
southern zone (PZZ676), winds are expected to drop below SCA
levels this morning, and mostly remain below SCA levels thru Thu
morning - SCA conds are likely (80% chance) Thu afternoon thru
Sun evening. There is a 30% chance of GALE force winds at times
Fri afternoon thru Sat eve.

In the nearshore waters N of Pt Conception, SCA winds are likely
(80% chance) during the afternoon/eve hours thru Sat. There is a
moderate to likely chance of SCA level seas Friday night into
early Sunday morning.

In the Santa Barbara Channel, SCA level winds are likely (80% chance)
across western portions during the afternoon/eve hours Fri thru Sat.

In the southern inner waters, SCA conds are not expected thru Sun
night.

&&

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

&&

$$

PUBLIC...MW/Hall
AVIATION...DB
MARINE...DB/Black
SYNOPSIS...Hall

weather.gov/losangeles

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