744 
FXUS66 KLOX 092106
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA 
206 PM PDT Sat Oct 9 2021

.SYNOPSIS...09/204 PM.

A couple of upper level troughs of low pressure will move past the
area and bring gusty northerly winds across southwestern CA at 
times through Tuesday. The winds will peak late Monday and Monday 
night when damaging wind gusts will be possible in the mountains 
and deserts. Temperatures will warm some through Sunday then cool 
back down through early next week. A warming trend is then 
expected mid to late next week.

&&

.SHORT TERM (TDY-TUE)...09/156 PM.

Sunny skies covered the forecast area early this afternoon with 
little change expected for the rest of the day. There were decent 
pressure gradients to the N early this afternoon (e.g., -3.0 mb 
LAX-DAG at 20Z) which has helped to sustain gusty mainly sub- 
Advisory level NW TO N winds over the mtns as well as portions of 
the SBA County S coast. The north flow will persist the rest of 
the day and should even increase into the evening across the SBA 
County S coast and mtns and the L.A./VTU Mountains, especially 
along the I-5 corridor, as an inside slider upper level trof moves
thru srn CA. Advisory-level wind gusts are expected for southern 
SBA County starting late today, with possibly Advisory-level gusts
at times for the I-5 corridor this evening. 

Temps across the region are expected to warm several degrees over
yesterday thanks to the northerly offshore flow and abundant 
sunshine. Even so, it will still be about 5-10 deg below normal 
for most areas this afternoon. Highs for much of the inland 
coastal areas, vlys and lower mtns should be in the 70s.

That rather sharp inside slider over the region this afternoon 
will move quickly E and out of CA by later tonight, followed by 
flat upper level ridging on Sun, with H5 heights up to 583-584 dam
by late Sun morning. Offshore pressure gradients to the N and E 
are expected Sun morning, with breezy to gusty NE winds across the
usual wind-prone areas of VTU/L.A. Counties as well as over 
SLO/SBA Counties especially for the interior SBA County mtns and 
thru the Santa Lucia Range. For the coast and vlys, winds will 
switch around to onshore Sun afternoon with gusty W to NW winds 
expected, strongest along the Central Coast and the southern SBA 
County coast west of Goleta. The offshore flow and plenty of 
sunshine on Sun will help to warm temps 5-10 deg over today, with 
highs near normal to a few degrees above normal for many areas. 
The warmest inland coastal areas and adjacent vlys should top out 
in the lower to mid 80s.

A vigorous upper level trof is forecast to move into nrn CA Sun 
night, then into eastern CA on Mon and into the central Great 
Basin Mon night. H5 heights over swrn CA are forecast to drop to 
560-568 dam by late Mon. This much stronger and sharper inside 
slider upper level trof will substantially increase northerly 
gradients across the forecast area Mon afternoon into Mon night. 
These gradients combined with excellent upper level support and 
cold air advection will usher in strong and gusty NW to N winds 
across much of the fcst area Mon afternoon and Mon night, with 
widespread high-end Wind Advisories likely. There is also the
potential for warning-level wind gusts across the mtns and into 
the Antelope Vly, and High Wind Watches will be issued for these 
areas with this afternoon's forecast package.

There may be some low clouds along the central Coast Sun night 
into early Mon, otherwise skies are expected to be mostly clear 
thru Mon. Temps will turn sharply cooler on Mon across most of the
region, except a few degrees warmer for the SBA County S coast. 
Most areas should have highs 5-15 deg below normal, with the 
warmest coast and adjacent vlys reaching the lower 70s, except mid
70s to low 80s along the SBA County S coast.

The upper level trof will move further E on Tue, with rising H5 
heights over the forecast area up to 572-574 dam in the afternoon 
and a broad NW flow aloft. Gusty N winds possibly to Advisory 
levels at times can be expected to linger across the wind-prone 
areas of SBA/VTU/L.A. Counties Tue morning before diminishing some
Tue afternoon. Skies will be sunny across the region on Tue, but 
temps will remain quite cool at about 5-15 deg below normal even 
with a slight warmup for most of the coast and vlys.

.LONG TERM (WED-SAT)...09/158 PM.

A broad NW flow aloft with H5 heights around 574-576 dam can be 
expected on Wed. Upper level ridging over the E Pac will edge 
closer to the coast on Thu with H5 heights increasing to around 
580-582 dam. The upper level ridging will move over srn CA on Fri 
then move well E of the region Sat with a broad SW flow aloft 
expected and H5 heights falling slightly to around 578-580 dam.

Offshore flow during the night and morning hours can be expected 
during the extended period, with the EC a little more robust with 
the offshore pressure gradients. It looks like mostly clear skies 
will prevail in all areas during the period, except possibly some 
low clouds and fog along the immediate  Central Coast Wed night 
into Thu morning. There will be a warming trend Wed thru Fri then 
turn slightly cooler for Sat. Temps are forecast to be 4-8 deg 
below normal on Wed, then warm to a few degrees above normal for 
most areas by Fri and continue into Sat. The warmest inland 
coastal areas and adjacent vlys should range from the 70s to 
around 80 Wed then warm into 80s by Fri.

&&

.AVIATION...09/1802Z.

At 1659Z at KLAX, there was no marine layer nor a surface based 
inversion.

High confidence in the 18Z CAVU TAFs.

KLAX...High confidence in the 12Z CAVU TAF. High confidence that 
any east wind component will be under 7kt.

KBUR..High confidence in the 12Z CAVU TAF.

&&

.MARINE...09/1241 PM.

High confidence in the current forecast through Tuesday. Moderate
confidence in the current forecast after Tuesday.

Outer waters...Small Craft Advisory (SCA) level winds will 
continue to generally increase across the coastal waters through 
the weekend. Steep short period seas are likely through the 
weekend. There is a GALE WARNING for the southern two zones and 
an SCA is in effect for the northern zone through late tonight. 
GALE WARNING winds will return to all outer waters late Sunday
afternoon through late Monday night. A large northwest swell will
build across the coastal waters between Sunday night and Monday.

Inner waters on central coast...Confidence continues to grow for 
SCA conditions between this afternoon and Tuesday. An SCA is in 
effect from this afternoon through this evening. Hazardous seas 
will likely be prevalent across the coastal waters between late
Sunday night and Tuesday and SCA level winds will return Sunday 
afternoon through Monday night. 

Inner waters of the southern California bight...A SCA is in effect
for this afternoon and evening. SCA level winds will again return
to the western Santa Barbara Channel Sunday afternoon through
Sunday night. Then, either a strong SCA or even GALE WARNING level
winds will affect the area Monday afternoon and Monday night.
Hazardous combined seas to around 10 feet are possible Monday 
into Monday night.

There is moderate (40-60 percent) chance of gales across the 
entire coastal waters Monday afternoon and night.

SCA level winds could linger for the waters from southwest to 
northwest of the Channel Islands through much of the latter half
of next week. Winds and seas look to fall below SCA levels across
the southern California bight. 

Later shifts will need to consider extending the GALE WARNING in
the outer waters into Sunday or Monday night.

&&

.BEACHES...09/111 PM.

A large northwest swell is expected to build over the coastal
waters between Sunday night and Tuesday. High surf will likely
develop at Central Coast beaches from Monday through Tuesday.
There is a moderate chance of high surf with sets in excess of 7 
feet at west facing beaches south of Point Conception between 
Monday afternoon and Tuesday morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 3 AM PDT Sunday for zones
      39-52. (See LAXNPWLOX).
     High Wind Watch in effect from Monday afternoon through late
      Monday night for zones 52>54-59. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zones 645-655. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Sunday for
      zones 650-670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 673-676. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Sunday for zones
      673-676. (See LAXMWWLOX).

&&

.HAZARD POTENTIAL OUTLOOK (TUE-SAT).

Widespread moderate to strong northwest to north winds are 
expected Monday night and Tuesday, including southern Santa 
Barbara County, the I-5 Corridor, and most coastal waters. Downed 
trees, power outages, large surf with strong currents, and 
dangerous driving and boating conditions are expected.

&&

$$

PUBLIC...Sirard
AVIATION...Sweet/Lund/ASR
MARINE...Sweet
BEACHES...Sweet
SYNOPSIS...Sirard

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