069
FXUS66 KLOX 031721
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
1021 AM PDT Sun Aug 3 2025

.SYNOPSIS...03/252 AM.

Skies will be mostly clear except for night through morning low
clouds and fog across coasts and lower valleys. Max temps will
remain slightly below normal through Tuesday but there will be
significant warming on Wed and Thu with potentially hazardous
heat levels on Thursday.

&&

.SHORT TERM (TDY-TUE)...03/815 AM.

***UPDATE***

Latest satellite and surface observations indicate areas of
stratus/fog across the coastal plain with clear skies elsewhere.
Also, smoke from the Gifford Fire is drifting across the area.
Current sounding data indicates marine inversion in the 1000 to
1400 foot range for depth. As for winds, westerly gusts of 25 to
35 mph are observed across the deserts and the Santa Ynez Range.

Forecast-wise for the immediate short term, no significant issues
are expected. Current stratus/fog should dissipate by the
afternoon for most areas although some stratus could linger at the
beaches (especially across Ventura/LA counties). Other than the
stratus, skies should remain mostly clear with some smoke from the
Gifford Fire. As for winds, the northerly offshore gradients look
to increase late this afternoon and tonight. So, Sundowner winds
across the Santa Ynez will increase this evening and the current
WIND ADVISORIES for southern SBA county look good. Northerly
winds also may approach advisory levels this evening across the
I-5 Corridor and this will need to be watched.

Overall, current forecast has good handle on the immediate short
term. So, no significant updates are expected.

***From Previous Discussion***

The persistent upper level pattern will continue through the short
term period (Tuesday) with the upper high to the ESE and the trof
to the NW. Hgts will wiggle around 590 to 592 dam. At the sfc both the
E/W and N/S gradients will follow the diurnal pressure curve. The
E/W grad will be weakly onshore in the morning and moderately
onshore in the afternoon. The N/S gradient is more interesting, it
will be weakly offshore in the morning and weakly onshore in the
afternoon. The offshore flow will peak Monday morning at around 2
mb.

Currently there is a 500 ft deep marine layer north of Pt
Conception. South of Pt Conception the marine layer is about 1000
ft deep due to a weak eddy. Low clouds will cover the csts (save
for the SBA south coast) and Santa Ynez/San Gabriel Vlys. The
shallower marine layer up north will produce some dense fog. The
onshore flow is not strong enough to prevent clearing and all
areas should be cloud free by noon. Max temps will be similar to
the past few days with readings near 70 at the beaches with mid
70s to mid 80s away from the nearshore area. The vlys will see max
temps in the mid 80s to mid 90s. These max temps are a few degrees
blo normal.

Late this afternoon through early evening a little meso high forms
across SLO and Kern counties. This will increase the local N/S
offshore gradients and produce advisory level northerly wind gusts
across the Santa Ynez range and the western coast of srn SBA
county. The I-5 corridor will also experience gusty winds just
under advisory (45 mph) levels.

No real changes expected for Monday. The northerly flow will cool
the interior some and the gusty winds will continue across the SW
portion of SBA county.

Slight hgt rises and a switch to westerly flow across the interior
will bring some warming to most areas on Tuesday. Still it will be
hard to distinguish any day to day changes.

Also of note, areas of smoke are expected to impact portions of
Santa Barbara, San Luis Obispo, and Ventura Counties through at
least the rest of this weekend, in association with the Gifford
Fire.

.LONG TERM (WED-SAT)...03/1202 AM.

A significant warming trend will begin Wednesday at the upper
strengthens and moves westward. Hgts will increase to between 594
and 595 dam. On Friday the trof to the NW reasserts itself and
hgts will fall to about 592 dam. Onshore flow will remain at the
sfc so most of the csts will be protected from the increase in
temps. The night through morning low clouds will continue and due
to the increasing strength of the marine inversion may struggle to
clear some beaches.

Look for 2 to 4 locally 5 degrees of warming away from the csts
each day Wed and Thu. The weakening upper high Friday will allow
for 1 to 2 degrees or cooling.

Thursday will be the warmest day with the vly temps rising to 95
to 105 with isolated 107 degree readings in the western San
Fernando Vly. Max temps across the lower mtn elevations and far
interior will range from 100 to 108 degrees. Most of these highs
are 8 to 12 degrees above normal. Since it is August the daily
records are quite high but there is a 30 percent chc that there
will be record heat. The beaches will stay in the 70s but the
inland coastal sections could see max temps in the mid 90s. Min
temps will mostly be 2 to 4 degrees above normal but areas right
at the top of the marine inversion (likely ~1000 ft) may see lows
in the lower to mid 70s. Evaluation of the need for heat hazards
will start early next week, but preparing now for very hot
weather next week is strongly encouraged.

On Saturday slightly lower hgts and increased onshore flow will
lead to at least 3 to 6 degrees of cooling.

&&

.AVIATION...03/1720Z.

At 1638Z at KLAX, the marine layer was 1100 feet deep. The top of
the inversion was at 3100 feet with a temperature of 24 C.

High confidence in TAFs for KWJF/KPMD.

Moderate confidence in TAFs for KBUR/KVNY with a 20-30% chc of
LIFR conds after 10Z Mon.

Low to moderate confidence in remainder of TAFs. There is a 40% chance
of VLIFR to LIFR cigs at KPRB after 08Z Mon.

KSBP and KSMX may remain VFR after clearing, however there is a
40% chance for VLIFR conds if cigs do arrive.

There is a 30% chance of KSBA remaining VFR after clearing this
morning, and if cigs do arrive, there is a 30% chance of VLIFR to
LIFR conds at KSBA.

There is a 40% chance of no clearing at KOXR and KSMO, with cigs
hugging the beaches through the afternoon. If cigs do clear,
return of cigs at KOXR, KCMA, KSMO, KLAX, and KLGB could arrive as
late as 10Z Mon, with a 30% chance of VLIFR- LIFR conds
overnight.

Intermittent vis reduction due to smoke will be possible at KSMX,
KSBP, and KSBA through the period.

KLAX...Moderate confidence in TAF. Timing of flight cat changes
could be off by +/- 2 hours, with low clouds returning Sun night
as early as 04Z or as late as 10Z. There is a 30% chance of 1/2SM
FG VV002 conds overnight Sunday into Monday. No significant
easterly wind component is expected.

KBUR...Moderate to high confidence in TAF. There is a 20% chance
of BKN004 conds after 10Z Mon.

&&

.MARINE...03/731 AM.

For the Outer Waters, moderate to high confidence in current
forecast. High confidence in widespread Small Craft Advisory
(SCA) winds through Wednesday, with GALE Force wind gusts likely
this afternoon through the late night hours, strongest across the
waters north of Point Sal (PZZ670). There is a 30% chance of GALE
Force wind gusts across the waters south of Point Conception
Monday and Monday night. Seas are expected to reach SCA criteria
across much of the Outer Waters this afternoon through late Monday
night. Next weekend looks to be much quieter in regard to seas
and winds, but will continue to monitor for any changes.

For the Inner Waters north of Point Sal, moderate to high
confidence in current forecast. High confidence in SCA level
winds during the afternoon and evening hours through Tuesday, with
a 50% chance of Gale Force wind gusts across the western portion
this afternoon and evening. There is a 30-40% chance of SCA level
winds on Wednesday and Thursday, likely followed by benign
conditions heading into next weekend.

For the Inner Waters south of Point Conception, moderate to high
confidence in current forecast. SCA level winds are likely today and
Monday during the late afternoon and evening hours across the
Santa Barbara Channel (strongest across western portion). Lower
chance on Tuesday. Otherwise and elsewhere, good confidence in
winds and seas remaining below SCA criteria through Friday.

Tropical Storm Gil, currently south of Cabo San Lucas, will
generate a ~12 second south swell of 2 to 4 feet into Monday.

Visibilities will likely lower through the weekend, with dense fog
possible, especially along the Central Coast.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory now in effect from 5 PM this afternoon to 3 AM
      PDT Tuesday for zones 349-351. (See LAXNPWLOX).
     Wind Advisory remains in effect from 9 PM this evening to 5
      AM PDT Monday for zone 352. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 PM PDT this afternoon
      for zones 645-670-673-676. (See LAXMWWLOX).
     Gale Warning in effect from 3 PM this afternoon to 3 AM PDT
      Monday for zones 645-670-673-676. (See LAXMWWLOX).
     Small Craft Advisory in effect from 3 PM this afternoon to 1
      AM PDT Monday for zone 650. (See LAXMWWLOX).

&&

$$

PUBLIC...Rorke/Thompson
AVIATION...Lund
MARINE...Black/Lund
SYNOPSIS...30

weather.gov/losangeles

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