583
FXUS66 KLOX 131312
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
612 AM PDT Tue Aug 13 2024

.SYNOPSIS...13/1226 AM.

Temperatures will remain near normal this weekend with little
day-to-day changes. Night- to- morning low clouds and fog will
push into coastal areas at times.

&&

.SHORT TERM (TDY-THU)...13/508 AM.

Low clouds were widespread on the Central Coast and in the Santa
Ynez Valley this morning, as they have been during the past few
mornings. The difference was S of Pt. Conception, where there was
a more expansive area of low clouds off the coast, some of which
had already surged into southern L.A. County. Expect patchy low
clouds or areas of low clouds across coastal sections of L.A./VTU
Counties this morning. There is an slight chance that clouds could
push into southeastern SBA County as well. Expect low clouds to
clear by mid to late morning, except possibly as late as noon at
the immediate beaches.

W-E pressure gradients were about the same as they were on Mon
morning. N-S offshore gradients have increased slightly across
SBA County, and have gone from onshore to neutral across L.A.
County. However, there were no wind issues early this morning.
This afternoon, there will be some gusty winds in the Antelope
Valley and thru the Highway 14 Corridor, but winds should remain
below advisory levels. N-S gradients will increase across SBA
County later today and tonight, with gusty winds likely across the
southwest coast of SBA County and the Western Santa Ynez Range.
Even there, winds should stay just below advisory levels. Slight
height falls with a weak trough pushing in the West Coast and
some cooling at 950 mb should lead to a couple of degrees of
cooling in most areas today. The exception may be across southern
SBA County foothills, where north winds may bring some warming if
they surface by evening.

The weak upper trough will move east of the region later today and
tonight, and an upper level high will begin to build into the
forecast area from the southwest. Moderate onshore pressure
gradients from W to E will keep gusty winds Wed afternoon and
evening across the Antelope Valley and the Highway 14 Corridor
Wed, but again, likely below advisory levels. N-S gradients across
SBA County will increase, likely enough for some wind advisory
level winds across the southwestern coast and the western Santa
Ynez Range late Wed afternoon into Wed night. Gusty winds are also
likely in the I-5 Corridor Wed night. Expect the low cloud
pattern tonight/Wed morning to be similar to that of this morning,
confined to the coastal plain, except it should remain clear
across the south coast of SBA County. Height rises and some
warming at 950 mb should lead to some warming in most areas Wed,
but do not expect max temps to be much (if at all) above normal
in most areas.

The upper high will strengthen a bit Thu, and heights will rise
slightly. There may be some reduction in low cloud coverage Wed
night/Thu morning as the marine layer thins. Expect another round
of gusty W winds in the Antelope Valley and Highway 14 Corridor
Thu afternoon and evening, with advisory level NW to N winds
possible across southern SBA County late Thu/Thu night. Max temps
should be up slightly on Thu, with highs peaking near 100 degrees
in the Antelope Valley and the hottest valley locations west of
the mountains.

.LONG TERM (FRI-MON)...13/500 AM.

The upper high will shift just to the east of the forecast area
Fri as a broad trough moves into the eastern Pacific. The upper
high will strengthen and move to a location just to the southeast
of the Four Corners area Sat, then it will move little thru Mon.
Meanwhile, a trough will linger just to the west of CA Sat thru
Mon. The position of the forecast area between these two upper
features will make for a rather uneventful weather pattern Fri
thru Mon. Southwesterly flow aloft is expect most of this period,
which should keep any monsoonal moisture and any chance of
showers/tstorms to the east of the region. Heights will fluctuate
slightly thru the period. In a very general sense, based on heights
and pressure gradients, expect some cooling Fri and Sat, with small
warming Sun and Mon. Night/morning low clouds and fog will be
confined to the coastal plain and possibly the lower valleys. Do
not expect wind issued Fri and Sat, except for some gusty
afternoon/eve winds in the Antelope Valley. N-S gradients will
become increasingly offshore across SBA County Sun and Mon, so
expect some gusty NW winds across southwestern SBA County during
the late afternoon thru evening hours on those days.

&&

.AVIATION...13/1311Z.

At 1243Z at KLAX, the marine layer was 800 ft deep. The top of
the inversion was at about 2600 ft with a temperature of 24 C.

High confidence in TAFs for KPRB, KSBA, KBUR, KVNY, KPMD, and
KWJF.

Low to moderate confidence in remaining TAFs. Timing of cat
changes may be off by +/- 3 hours. There is a 30-40% chance that
any TAF site will have VFR conds through the period. There is a
30% chance of IFR conds at KOXR and KCMA through 16Z.

KLAX...Low to moderate to low confidence in TAF. There is a
30-40% chance that conds will remain VFR through the period. High
confidence in no significant east wind component.

KBUR...High confidence in VFR TAF.

&&

.MARINE...13/420 AM.

For the outer waters, current forecast looks on track with Small
Craft Advisory (SCA) level winds expected through the weekend.
There is also a 20-40% chance of gale force wind gusts at times
Wednesday night into Friday. Seas will be steep and choppy through
Friday.

For the inner waters north of Point Sal, SCA level winds are
likely each afternoon through evening through at least Friday,
with a 30-40% chance of continuing through Sunday.

For the inner waters south of Point Conception, there is a
40-50% chance of SCA wind gusts for the western Santa Barbara
Channel during the afternoon into late evening hours through
Thursday. Otherwise, conds will remain below SCA levels over the
southern inner waters through Saturday night.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 645-670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...DB
AVIATION...Lund
MARINE...Lund/Phillips
SYNOPSIS...Munroe/KL

weather.gov/losangeles

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