Brandeis California Weather Forecast Discussion

000
FXUS66 KLOX 111022
AFDLOX
Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
322 AM PDT Sat Oct 11 2025
.SYNOPSIS...11/317 AM.
Gusty northwest to northeast winds will increase through
today, then shift to northeast and weaken on Sunday. This will
result in drying conditions through the weekend. A storm system
will affect the area next week late Monday through Wednesday,
with most of the rainfall on Tuesday. Expect widespread light to
moderate rain and a potential for locally heavy showers and
thunderstorms.
&&
.SHORT TERM (TDY-MON)...11/322 AM.
This weekend, weather conditions will be driven by the trough
associated with a low pressure system centered over the Pacific
Northwest. A powerful jet aloft and strong north-to-south surface
pressure gradients will produce gusty winds. Already northerly
Sundowner Winds are occuring across southwestern Santa Barbara
County (gusts 35-45 mph). Northerly winds will strengthen through
today, peaking this afternoon into late tonight. Gusty wind are
expected for the Central Coast, most of Santa Barbara County
(including the southeastern coastal portion), the HWY 33 Corridor,
the I-5 Corridor, Antelope Valley and adjacent foothills, Santa
Clarita Valley, Santa Susana Mountains, Santa Monica Mountains,
and the western San Fernando Valley. Wind Advisories have been
issued for the areas expected to see the most significant winds,
where gusts of 30-50 mph will be common. There is a 30 percent
chance that a High Wind Warning will be needed for the I-5
Corridor tonight.
By Sunday morning, as the trough travels to the east, winds will
become more northeasterly and generally weaken. Gusts of 20 to 40
mph will be possible across mountains and favored foothills,
especially the Western San Gabriel Mountains, Santa Susana
Mountains, and interior Santa Barbara County Mountains. The wind
shift will yield mostly clear skies, drier humidities, and briefly
elevated fire weather conditions on Sunday.
The trough will bring a cooler airmass to the region and as a
result temperatures will drop compared to yesterday. Temperatures
in the mid 70s to mid 80s will be common this weekend, either
normal or just below normal for this time of year. Monday, as the
weather pattern transitions with the approaching storm, daytimes
highs will fall dramatically. Many locations will struggle to
reach the low 70s. Rainfall chances will begin during the day
Monday for northern areas (mainly San Luis Obispo County), with
the core of the rain traveling southward Monday night (see the
long term discussion).
.LONG TERM (TUE-FRI)...10/231 PM.
Computer projections continue to show a yet-to-form low pressure
system riding the west coast Monday through Tuesday, before
pivoting inland on Wednesday. While there remains some range in
the timing and exact track of this system, which will determine
which of the four counties will see the highest rain amounts and
rates, the range of outcomes is narrowing to the point that we can
advertise a most likely outcome. At this point, the period of
focus remains centered on Tuesday (from 3am to 9pm). The area of
focus remains San Luis Obispo and Santa Barbara Counties, where
amounts between 1 and 2 inches look favorable. For Los Angeles and
Ventura Counties, amounts between 0.5 and 1.5 inches look
favorable (with the highest end of the range over Ventura County).
Favored foothills and mountains will likely see about double
those amounts over the 4 counties. The focus could shift to the
north or south depending on the track of the storm, but the slim
majority favor this outcome. Rain rates look behaved peaking
between 0.10 and 0.33 inches per hour - which would limit any
hydro impacts to the roads and outdoor activities. Unfortunately
there is a caveat to that all-clear message. The storm could slow
down (which about 10% of the projections show) which would
increase those totals. This storm is also very dynamic, with a
concentrated area of diffluence aloft and an upper level jet over
120 knots. That means thunderstorms are on the table, and the
associated potential of isolated heavy rain cells, lightning, and
even severe weather (strong winds or a tornado). Right now, with
the consensus track, those risks are highest over San Luis Obispo
and Santa Barbara Counties Monday Night into Tuesday, but that
could shift in time and place depending on that track.
Unsurprisingly daytime temperatures will plummet. Highs in the 60s
will be most common Tuesday and Wednesday (15-25 degrees below
normal). Overnight temperatures will be mild with the added
moisture and sky cover.
A few of the projection also so another low pressure system
spawning off the other one and retrograding westward back over
California Thursday or Friday. A few more projections dont. As
such, the is about as wide of a range of outcomes for the end of
next week, anything from more rain, thunderstorms, and coldness,
to warming and drying conditions.
&&
.AVIATION...11/0728Z.
At 0648Z at KLAX, the marine layer was 900 ft deep. The top of
the inversion was around 1700 ft with a temperature of 24 C.
Overall, moderate confidence in TAF Package. VFR conditions are
generally expected with the exception of IFR CIGs possible for
KSMO (30%) and KPRB (40%). There is a 30% chance of no cigs
developing at KLAX and KLGB, and and the timing of any cigs that
develop may be off by 2 hours. 10% chc for LIFR/IFR CIGs at
KSBP/KSMX from 07Z-15Z Sat.
Periods of gusty west & north winds are likely for many terminals.
Wind gusts may be off by 5-10 kts and/or wind direction by 30
degrees at times.
For SBA and over the mountains, low-level wind shear is possible
through the period.
KLAX...Moderate confidence in TAF. Arrival of OVC005-010 cigs
expected between 12Z-15Z and clearing 16Z-18Z Saturday. Gusty
north winds are possible starting as early as 01Z Sunday (30%
chance of gusts up to 20 kt), by around 07Z Sun there is a 40%
chance of an east winds component of 8 kt.
KBUR...High confidence in TAF, except onset times of northerly
winds may be off by 2 hours. There is a 20% chance of northerly
gusts up to 20 kts after 00Z Sun.
&&
.MARINE...11/303 AM.
For the waters outside the southern California bight from
southwest through northwest of the Channel Islands, including the
nearshore waters along the Central Coast, winds will continue to
increase through this afternoon. Widespread Small Craft Advisory
(SCA) level conditions will occur continue through at least early
Sunday morning, and possibly into late Sunday night or early
Monday morning. There is a likely (60-80 percent) chance of GALES
through this evening, strongest from near Point Conception south
to San Nicolas Island. There could be lulls in the winds during
late night and early morning hours, but seas will likely remain at
SCA levels through Sunday. There is a 40-60 percent chance of
widespread SCA conditions lingering into early Monday morning. Due
to the GALES and hazardous seas, inexperienced boaters should
seek or remain in safe harbor.
Inside the southern California bight, SCA level winds are expected
mainly across western portions of the bight and the southern
portion of the Santa Barbara Channel adjacent to the Channel
Islands through late tonight. There is a high chance of widespread
SCA conditions developing this evening across the bight. Short-
period hazardous seas could develop across the Santa Barbara
Channel this evening, with winds and seas potentially reaching
Ventura County harbors, such as Ventura and Channel Islands Harbor
during this time. The strongest winds are expected across the
western portion of the Santa Barbara Channel, where a moderate-to-
high (30-50 percent) chance of GALES exists this afternoon and
evening.
Widespread SCA conditions with a moderate chance of GALES is
expected between Monday night and Tuesday night as a cold
front with a storm system moves over the region. Gusty south to
southwest winds will move over the coastal waters.
&&
.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect from noon today to 10 AM PDT Sunday
      for zones 88-350-352-353-375>379-381-383. (See LAXNPWLOX).
     Wind Advisory in effect from noon today to midnight PDT
      tonight for zones 340-341-346>348. (See LAXNPWLOX).
     Wind Advisory in effect until 10 AM PDT Sunday for zones
      349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 645-670. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Sunday for zones 645-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for zone
      650. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 3
      AM PDT Sunday for zone 655. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Monday for zones
      673-676. (See LAXMWWLOX).
&&
$$
PUBLIC...Schoenfeld/Kittell
AVIATION...Schoenfeld
MARINE...Hall
SYNOPSIS...RK/Schoenfeld
weather.gov/losangeles
Experimental Graphical Hazardous Weather Outlook at:
https://www.weather.gov/erh/ghwo?wfo=lox

NWS LOX Office Area Forecast Discussion