313
FXUS66 KLOX 312057
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
157 PM PDT Sun Aug 31 2025

.SYNOPSIS...31/156 PM.

A hot air mass will continue over the region through mid week as
high pressure aloft will remain anchored near the Four Corners
region. Monsoonal moisture will arrive again on Monday night and
Tuesday and keep a low but present risk of showers and
thunderstorms through the remainder of the week. A cooling trend
is possible by the upcoming weekend.

&&

.SHORT TERM (TDY-WED)...31/149 PM.

Another very warm to hot day over the forecast area, with many
areas away from the coast expected to top out between 95 and 105
deg this afternoon. Even the inland coastal plain should reach
into to low 90s. With the hot conditions, Heat Advisories are in
effect for most of the region.

Some low clouds and patchy dense fog were noted over the coastal
waters S of Point Conception early this afternoon, with some fog
along the VTU County beaches to the Malibu Coast. These low clouds
should diminish in coverage through sunset. Some cu buildups have
been noted over the mtns early this afternoon as well. An
isolated shower is possible this afternoon in these areas but
overall any chances of thunderstorms is about 5 percent or less.

A broad southerly flow aloft over the forecast area between an
upper level high near the Four Corners region and a weak upper
level low just off the Central Coast can be expected through Mon
night. However, a weak disturbance aloft embedded in this flow
is forecast to move into the area later Mon night. This system,
combined with significant amounts of mid-level moisture and some
instability aloft is expected to develop an area of showers with a
slight chance of thunderstorms over a good portion of VTU/L.A.
Counties generally after midnight Mon night into Tue morning.
Lingering mid-level moisture and instability will keep the slight
chance of showers and thunderstorms mainly over the mtns and
deserts Tue afternoon and early evening.

Upper level ridging will persist over srn CA Tue night and Wed.
It looks like enough mid-level moisture and increasing afternoon
instability will prevail over the VTU/L.A. County mtns for a
slight chance of thunderstorms Wed afternoon as well.

Otherwise, there will some low clouds and patchy dense fog along
some coastal areas each night and morning through Wed, with mostly
clear skies for the most part expected through the period except
for mostly cloudy skies over VTU/L.A Counties on Tue.

Temperatures will remain quite warm to hot away from the
immediate coast through Wed, with the aforementioned Heat
Advisories in effect through Tue for many areas. The Heat
Advisories may need to be extended into Wed for some areas as
well. However, cloud cover may affect the highs over VTU/L.A.
Counties on Tue, so the confidence in these forecast highs is
moderate.

Highs Mon thru Wed are forecast to be in the 95 to 105 degree
range away from the coast. Warm overnight lows in many areas will
contribute to the heat stress.

.LONG TERM (THU-SUN)...31/154 PM.

Models are in generally good agreement in the extended. It looks
like weak upper level ridging should build into the are on Thu
followed by weak upper level troffiness Fri thru Sun, with a broad
WSW flow aloft.

There is a non-zero chance (around 5-10 percent) of afternoon
thunderstorms over the San Gabriel Mtns Thu and Fri. Otherwise,
dry weather is expected Thu thru Sun. There should be varying
amounts of night and morning low clouds and fog for the central
Coast each day, with some low clouds developing along the L.A.
County coast next weekend. Otherwise, clear to partly cloudy skies
should prevail thru the extended. Temperatures will be near
normal to slightly above normal Thu then fall to several degrees
below seasonal norms by the weekend.

&&

.AVIATION...31/1755Z.

Around 1722Z at KLAX, the marine layer was 400 ft deep. The top
of the inversion was at 2400 ft with a temperature of 27 C.

Low confidence in TAFs for KSBA, KOXR, KCMA, KSMO, KLAX, and KLGB
due to uncertainty of low clouds. There is a chance for no low
clouds at KSBA (40%), KOXR (20%), KCMA (30%), KSMO (40%), KLAX
(40%), and KLGB (40%). Otherwise, timing of flight cat changes
may be off +/- 3 hours and minimum cig heights may be off +/- 300
feet. There is a 10-30% chance for vsbys less than 1SM, highest
chances at KOXR and KCMA.

High confidence in remaining TAFs. There is a 15% chance for
VLIFR/LIFR conds between 10Z and 17Z at KSMX and KSBP.

KLAX...High confidence in TAF through 03Z, then low confidence
thereafter. There is a 40% chance for no low clouds. If they do
arrive, there is a 25% chance for cigs OVC002-004 and 15% chance vsbys
1/2SM-1SM. Timing of arrival of low clouds may be off +/- 3 hours.
High confidence that any east wind component will remain below 7
kt.

KBUR...High confidence in TAF.

&&

.MARINE...31/137 PM.

A slight chance of thunderstorms exists for the Inner Waters south
of Point Conception Monday evening through Tuesday, especially
the waters adjacent to the Los Angeles and Orange County coasts.
Any thunderstorm may produce frequent lightning, rain, and gusty,
erratic winds.

Moderate confidence in 20-25 kt NW winds across the Outer Waters
from Point Sal north to Point Piedras Blancas continuing through
Labor Day (Monday). Moderate confidence in the remaining Outer
Waters remaining below Small Craft Advisory (SCA) criteria through
Monday morning, then a 30% chance of winds increasing to SCA
levels during the afternoon and evening hours Monday. Tuesday into
Thursday, winds will increase across the Outer Waters, but
highest chances for SCA winds focused around Point Conception
south to San Nicolas Island. A relative lull in winds will be
likely each morning.

Moderate confidence in forecast for the nearshore waters along
the central coast. Winds and seas will remain relatively light and
small into Tuesday, but winds look to increase Wednesday and
Thursday afternoon and evening.

Aside from seasonal afternoon thru evening localized NW wind
gusts to 20 kts in the far Western Portion of the Santa Barbara
Channel and the San Pedro Channel, light winds and small seas will
be common for the nearshore waters south of Point Conception
through Labor Day. Winds will increase in speed and coverage
Tuesday through Thursday.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Heat Advisory remains in effect until 6 PM PDT Tuesday for
      zones 38-88-344-345-353-356>358-368>379-548. (See LAXNPWLOX).
     Beach Hazards Statement in effect through Monday evening for
      zones 340-346-354-362-366. (See LAXCFWLOX).
     Heat Advisory remains in effect until 6 PM PDT this evening
      for zones 341>343-347>349-351. (See LAXNPWLOX).
     Heat Advisory now in effect until 6 PM PDT Tuesday for zone
      352. (See LAXNPWLOX).
     Heat Advisory now in effect until 6 PM PDT Monday for zone
      355. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Tuesday for
      zone 670. (See LAXMWWLOX).

&&

$$

PUBLIC...Sirard
AVIATION...Lewis
MARINE...Lund/Lewis
SYNOPSIS...Hall/Sirard

weather.gov/losangeles

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