Wagner, California Weather Forecast Discussion

220
FXUS66 KLOX 260647
AFDLOX
Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1147 PM PDT Thu Sep 25 2025
.SYNOPSIS...25/245 AM.
A cutoff trough of low pressure off the Central California coast will
wobble back to south through tonight. A cooling trend is expected
through the weekend as the trough will linger over the area for
several days. Below normal temperatures are expected to continue
into next week. A deep marine intrusion will make low clouds and
fog a staple of the forecast with the possibility of night through
morning drizzle. Clouds may struggle to clear from the beaches
each day. Showers chances will continue across the interior
portions of the area and over the mountains and desert.
&&
.SHORT TERM (THU-SUN)...25/825 PM.
***UPDATE***
A few showers and thunderstorms rolled through SLO and Santa
Barbara Counties this afternoon and a flood advisory was issued
for portions of the Madre and Gifford Fire burn scars.
Temperatures trended quite a bit lower today, with highs 5 to 10
degrees lower in most of Los Angeles and Ventura counties as well
as southern Santa Barbara County. Expecting the cooling trend to
continue for coastal areas where highs should trend a few degrees
cooler as the marine layer deepens and works its way into
most valleys, including as far as the Santa Clarita Valley.
Further inland outside the marine influence, highs may rise a
couple degrees as 950 mb temperatures increase slightly. There is
a low chance for a few scattered thunderstorms and showers across
the mountains in LA, Ventura, and eastern Santa Barbara counties
along with the Antelope Valley in the afternoon and evening hours
Friday. The upper level low pressure system will shift to the
southeast through the day, and these storms would move in from the
northeast as they wrap around the low. There is a very low but
present chance for a shower to move into the valleys and even to
the coasts. Any flooding risk is very low at this point.
***From Previous Discussion***
Overall, 12Z models in good synoptic agreement through the period.
Main feature of note will be an upper low. All models move this
feature across Central CA tonight then drop it over the
southeastern deserts Friday and it spins over that area through
Sunday.
Forecast-wise, main issue in the short term will be shower and
thunderstorm potential as moisture/instability wrap around the
upper low. Through this evening, there will continue to be a
chance of some showers/thunderstorms across interior sections of
SLO/SBA/Ventura counties as the low begins to move to the
southeast. For Friday, models and their respective ensembles are
not picking up on too much activity. However, given the developing
situation, will include slight chance POPs Friday afternoon for
the eastern San Gabriel mountains.
On Saturday, things look to get much more interesting. Models
wrap around some decent moisture and instability across the area,
basically from eastern Santa Barbara county down to Los Angeles
county. So, there will be a chance of showers and thunderstorms
for all of Ventura/LA counties as well as eastern Santa Barbara
county and all the adjacent coastal waters. Any thunderstorms that
develop will be capable of producing brief heavy rain, localized
flooding, abundant lightning, hail and strong/erratic outflow
winds. Current SPC Outlook has this area in general thunderstorm
risk for Saturday and WPC has part of the area in a Marginal Risk
for excessive rainfall.
On Sunday, the low will begin to move slowly eastward into
Arizona. So, the threat of showers and thunderstorms will diminish
greatly. However, there will still be enough moisture/instability
to warrant a slight chance of afternoon showers/thunderstorms over
the higher elevations of SBA/Ventura/LA counties.
Other than the above convective issues, no major concerns are
expected. An increase in northerly offshore gradients will
generate some low-end advisory-level Sundowner winds across the
western Santa Ynez Range tonight and a WIND ADVISORY remains in
effect. The marine layer stratus should remain through the weekend
with low clouds pushing well inland each night. However, there is
a chance the marine layer clouds could be disrupted by the
convective activity, especially Saturday night.
.LONG TERM (MON-THU)...25/118 PM.
For the extended, 12Z models continue to exhibit good synoptic
agreement through the period. On Monday/Tuesday, a rather vigorous
front will roll across northern/central California, bringing
significant early season rainfall to those areas. For our "neck
of the wood," the tail end of this system will graze San Luis
Obispo and Santa Barbara counties. So, there will a 20-30% chance
of light rain Monday night through Tuesday night from Santa
Barbara county northward with dry conditions expected for Ventura
and LA counties. Dry conditions are expected for the balance of
the day on Wednesday and Thursday.
With the above pattern, a cooling trend can be expected Monday and
Tuesday with plenty of night/morning clouds and fog and good
onshore gradients. For Wednesday and Thursday, temperatures will
begin to rebound slightly, but still remain below seasonal
normals.
&&
.AVIATION...26/0646Z.
At 0606Z at KLAX, the marine layer was 2000 ft deep. The top of
the inversion was 2800 feet with a temperature of 20 C.
High confidence in TAFs for KPMD and KWJF.
Low to moderate confidence in remainder of TAFs. Timing of flight
cat changes may be off by +/- 2 hours, and conditions may be off
by 1 flight category than forecast at times. There is a 30%
chance of a couple hours of VFR conds at KSBA, KCMA, KOXR, KSMO,
and KLAX, and a 30% chance of little to no clearing at KLGB,
KVNY, and KBUR.
KLAX...Low to moderate confidence in TAF. There is a 30%
chance of a couple hours of VFR conds. There is a 20% chance of
an east wind component of 8 kt between 12Z-17Z Fri.
KBUR...Moderate confidence in forecast. There is a 30% chance
little to no clearing today.
&&
.MARINE...25/653 PM.
For all the Outer Waters, Small Craft Advisory (SCA) level northwest
winds are expected to continue into early Friday morning. Seas
will build, peaking at around 7 to 9 feet on Friday.
Across the inner waters north of Point Sal and the Santa Barbara
Channel, SCA winds will continue into evening, with the strongest
winds near Point Conception and San Miguel Island. Otherwise,
there is a small chance (20 percent) of local SCA gusts across the
San Pedro Channel this afternoon.
This weekend into early next week, southerly swell up to 5 to 7
feet is likely to impact the coastal waters.
&&
.BEACHES...25/233 PM.
A moderately-long period southerly swell will develop across the
coastal waters this weekend into early next week, generated by
Hurricane Narda. Hazardous rip currents and elevated surf are
likely for south-facing beaches, especially across Los Angeles
and Ventura Counties as well as Avila Beach and Port San Luis for
the Central Coasts. Additionally, particularly vulnerable south-
facing beaches may see some low- to- moderate coastal flooding
impacts. A High Surf Advisory and a Coastal Flood Advisory may be
needed for the peak of the event (Sunday through Tuesday).
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory remains in effect until 3 AM PDT Friday for
      zones 349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 AM PDT Friday for
      zones 670-673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Thompson/Lewis
AVIATION...Schoenfeld
MARINE...Schoenfeld/Lund
BEACHES...Hall/Schoenfeld/Lund
SYNOPSIS...Hall
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion