255
FXUS66 KLOX 170016
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
516 PM PDT Fri Aug 16 2024

.SYNOPSIS...16/139 PM.

Aside from night and morning low clouds and fog near the coast,
mostly quiet weather is expected through next week. Hazardous
heat will be possible next Tuesday or Wednesday for the interior.

&&

.SHORT TERM (TDY-MON)...16/139 PM.

Aloft, deep low pressure will remain nearly stationary off the
Pacific Northwest coast through early next week, while a midlevel
ridge strengthens over the south-central states. Midlevel heights
over the local area will change little through early next week,
while dry southwesterly flow prevails. At the surface, generally
light onshore flow will keep high temperatures a few to several
degrees below normal near the coast through early next week, with
highs over interior areas of a few to several degrees above
normal. Modest offshore pressure gradients for SBA-SMX will
facilitate sub-advisory Sundowner winds across southern Santa
Barbara County each day. Night and morning low clouds and fog will
dissipate by mid-day each day.

.LONG TERM (TUE-FRI)...16/139 PM.

Early next week, the upper low and an associated trough off the
Pacific Northwest coast will weaken and de-amplify. Midlevel
height rises over the local area will facilitate the westward
extension of the south-central states ridge. In response to these
developments, HeatRisk will have the potential to increase to the
Moderate to perhaps Major category, with a 30% chance for heat
headlines to become necessary on Tuesday or Wednesday over
interior areas. Light onshore flow will keep temperatures closer
to normal near the coast, where the rising heights should foster
shallower marine-layer depths and greater chances for patchy dense
fog at night and in the morning. Then for late next week, the
latest medium-range model consensus indicates the aforementioned
trough and low becoming reinforced with heights aloft falling
across the local area. Correspondingly, a cooling trend is
expected for Thursday and Friday.

In general, dry conditions should prevail through much of next
week. However, there is a remote chance (currently less than 10%)
for convection to develop over the LA and Ventura County
Mountains between Tuesday and Wednesday -- when there will be an
opportunity for monsoonal moisture to extend into the area to the
south of the aforementioned de-amplifying trough. Despite the
somewhat favorable moisture trajectories, larger-scale forcing for
ascent should be quite weak, and thus confidence in convective
development is currently low.

&&

.AVIATION...17/0015Z.

At 2333Z at KLAX, the marine layer was 950 ft deep. The top of
the inversion was near 2200 ft with a temperature of 27 deg C.

High confidence in the 00Z TAFs for KPRB, KBUR, KVNY, KPMD, and
KWJF.

Moderate confidence in the Los Angeles County coastal TAFs.
Arrival of cigs may be off +/- 2 hours from current forecasts.
Cig/vsby restrictions may shift between MVFR to IFR between 08Z
and 14Z. CIGs may be period with conditions shifting to MVFR
occasionally during the overnight period.

Low confidence in remaining coastal TAFs. Arrival of cigs may be
off +/- 3 hours from currents forecast and minimum flight cat may
be off by 1 cat at any time after cigs arrive. There is a 30%
chance of VLIFR conditions at KSMX and KOXR at any point after
cigs arrive. There is a 20-30% chance KSBP remains VFR thru the
period.

KLAX...Moderate confidence in the 00Z TAF. There is a 30% chance
that CIGs arrival is delayed until 08Z. Flight categories may
shift to VFR at times with CIGs becoming SCT. No significant east
wind component is expected.

KBUR...High confidence in VFR conds through the period for the 00Z
TAF.

&&

.MARINE...16/132 PM.

For the offshore waters from the Central Coast to San Nicolas
Island (the outer waters), high confidence in SCA level winds for
the two southern zones through Monday. For the furthest northern
zone, high confidence in SCA level winds through tomorrow morning,
with moderate confidence in SCA level winds continuing thru
Monday.

For the nearshore waters off the Central Coast, moderate
confidence in SCA level winds through this evening. Moderate
confidence in conditions remaining below SCA levels through
Monday.

For the Santa Barbara Channel, high confidence in winds below SCA
levels through Saturday. Moderate confidence in SCA level winds
in the Western Portion of the channel Saturday afternoon and
evening. Then, high confidence in winds remaining below SCA
levels Sunday thru Monday. In the eastern portion, high confidence
in conditions remaining below SCA level through the Monday.

For the southern inner waters, high confidence in conditions
staying under SCA levels through Monday.

With a shallow marine layer, moderate confidence in patchy dense
fog with visibilities under 1 nautical mile effecting the Central
Coast waters and southern inner waters tonight thru tomorrow
morning.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
PZ...Small Craft Advisory in effect until 9 PM PDT this evening
      for zone 645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 9 AM PDT Saturday for
      zone 670. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Monday for
      zones 673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Cohen
AVIATION...Smith
MARINE...Lewis/Kittell
SYNOPSIS...Cohen

weather.gov/losangeles

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