Neenach, California Weather Forecast Discussion

014
FXUS66 KLOX 081920
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1220 PM PDT Mon Sep 8 2025
.SYNOPSIS...08/858 AM.
A significant cooling trend will begin today as a low pressure
system approaches northern California. This will result in much
cooler temperatures and morning drizzle across Southwest
California by Wednesday and Thursday. In addition, marine layer
clouds will expand across coastal areas and well inland over the
valleys. A small warming trend is then expected Friday into the
weekend.
&&
.SHORT TERM (TDY-THU)...08/1020 AM.
***UPDATE***
Pretty quiet morning weather-wise so far. The marine layer was
1400 ft at Vandenberg this morning, allowing clouds to push well
into the valleys north of Point Conception, however south of Point
Conception, only a few locations saw some patchy clouds. Today
will be the start of the cooling trend with temperatures in the
90s across the interior areas, but 70s to 80s for areas closer to
the coast (most areas around 1-5 degrees below normal).
The marine layer will deepen tonight as the trough starts to move
in, and low clouds and patchy fog will be possible as far as the
San Fernando and San Gabriel valleys, as well as up the Conejo
Grade for Ventura. However, gusty advisory sundowner winds will
affect the SW portion of Santa Barbara County this evening and
overnight and help keep the clouds away from the SBA south coast.
With the deepening marine layer, some very light drizzle will be
possible overnight tonight and into Tuesday morning along coastal
locations.
The forecast looks to be in shape and no morning updates were
needed.
***From Previous Discussion***
An upper low will move into Nrn CA today and then will sit and
spin through Wednesday while deepening slightly. Flow over Srn CA
will be more and more cyclonic. Hgts will start out at 590 dam
today but will steadily fall to 580 dam by Wednesday. Onshore flow
will prevail through the period both to the north and east (There
might be a few hours of weak offshore flow from the north in the
mornings).
Low clouds and fog will increase in depth coverage and penetration
each day as the cyclonic flow lifts the marine layer steadily
through the period. The marine layer is about 1000 ft deep now but
will be over 3000 ft Wednesday. Currently the low clouds are
confined to the Central Coast and the Paso Robles area. It is
likely (70 percent chc) but not definite that low clouds will
develop across the LA/VTA csts towards dawn. The best lift will
occur Wednesday morning and drizzle if possible across all csts
and vlys.
The lowering hgts and deepening marine layer will team up to bring
a three day cooling trend to the area. Most areas will see 3 to 6
degrees of cooling today, followed by 2 to 4 degrees of coastal
cooling and 5 to 10 locally 12 degrees of cooling in the vlys (due
to the marine layer penetration). Wednesday will be cooler still
with another 2 to 5 degrees of cooling possible. Vly in the upper
80s to mid 90s today will end up in the upper 70s to mid 80s on
Wednesday. Wednesday`s max temps in the vlys will be 10 to 15
degrees blo normal.
There will be Sundowners each night as the NW winds across the
outer waters increase. A wind advisory valid from 5pm late this
afternoon to 5am Tuesday morning has been issued for the western
portion of the SBA south coast. Advisory level gusts are also
possible in the same area Tuesday night.
.LONG TERM (FRI-MON)...08/1231 AM.
On thursday the upper low will rotate out of Nrn CA and into Srn
CA with hgts falling to 577 dam (10 dam blo normal). Once again
there will be plenty of morning low clouds and maybe some more
drizzle. Max temp will continue to run 3 to 6 degrees blo normal
at the csts and 5 to 10 degrees blo normal in the vlys. The vlys
will only see max temps in the upper 70s to mid 80s.
The upper low will move out on Friday. The day will, again, start
out cloudy across he csts/vlys but the clearing will be a little
faster. Slightly higher hgts and slightly faster clearing will
bring 1 or 2 degrees of warming to the area.
A weak ridge will ride over the area on Saturday boosting hgts up
to 585 dam. There will not be much change in the onshore flow, but
the higher hgts may shrink the marine layer enough to keep it out
of most of the vlys. Clearing will be noticeably faster. Max
temps will respond with 2 to 4 degrees of warming bringing a few
readings in the lower 90s to the warmest vly locations. Despite
the 2 days of warming max temps will end up 2 to 4 locally 6
degrees under normals.
Not much change slated for Sunday as a weak trof flattens the
ridge but does not affect the hgts much at all.
&&
.AVIATION...08/1916Z.
At 1821Z at KLAX, the marine layer was 600 feet deep. The top of
the marine inversion was near 2200 ft with a temperature 23 C.
Moderate confidence in TAF. Wind speeds may be off by 5 kt during
peak winds across the deserts. Arrival cigs may be off by +/- 3
hours tonight, especially south of Point Conception. Flight
category may be one category lower than forecast at times.
KLAX...Moderate confidence in TAF. There is a 15% chance of no
cigs developing tonight, and cigs may arrive as early as 06Z and
as late as 13Z, with heights between OVC008-BKN018. No significant
east wind expected.
KBUR...High confidence in TAF until around 10Z, then there is a
30% chance of BKN008-015 cigs.
&&
.MARINE...08/857 AM.
For the Outer Waters south of Point Sal, Small Craft Advisory
(SCA) northwest winds are expected through at least Saturday.
North of Point Sal (including the nearshore waters) there is an
increasing chance of SCA winds Tuesday and Wednesay
afternoon/evening, with likely SCA winds Thursday through
Saturday.
South of Point Conception, areas of SCA level west winds are
likely each afternoon and evening through Wednesday night,
especially across the Santa Barbara Channel, around Point Dume,
and across the San Pedro Channel. Chances for SCA winds (50
percent) will remain through Saturday.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from 6 PM this evening to 5 AM PDT
      Tuesday for zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 5 AM PDT Tuesday for
      zone 650. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Wednesday for
      zones 673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Rorke/Lund
AVIATION...Schoenfeld
MARINE...Schoenfeld
SYNOPSIS...CC/KL
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion