982
FXUS66 KLOX 150334
AFDLOX

Area Forecast Discussion...UPDATED
National Weather Service Los Angeles/Oxnard CA
834 PM PDT Wed Aug 14 2024

.SYNOPSIS...14/800 PM.

Daytime highs will be near normal for most areas through the
weekend, followed by a warm up early next week. Patchy overnight
into morning low clouds and fog will impact coastal areas at
times. Gusty winds are likely across Southwest Santa Barbara
County and the Antelope Valley during the evening into overnight
hours through Thursday night.

&&

.SHORT TERM (WED-SAT)...14/833 PM.

***UPDATE***

Very little in the way of weather to update this evening. Skies
were sunny across the forecast area today. 500 mb hgts rose 3 dam
to 594 dam which is 5 dam higher than normal. Max temps responded
by warming 3 to 6 locally 8 degrees. There was a little cooling at
the beaches as the seabreeze arrived a little earlier than ydy.
Most max temps came in a few degrees either side of normals with
the big exception of the western half of the SBA south coast where
sundowner winds raised max temps to 10 to 15 degrees over normal.

Marine layer stratus forecast calls for a repeat of this morning`s
very minimal pattern. There is about a 40 percent chc that there
will be a little better coverage over the LA beaches.

Forecast is in good shape and no updates are planned.

***From Previous Discussion***

High pressure is currently building back over the region, as the
center of high pressure located south-southwest of the region
slides eastward. 500 mb heights will peak for the short term
Thursday night at 592- 594 dam, as the center of the anti-
cyclone starts to settle over the Desert Southwest. Friday and
Saturday will see a downward trend in heights, as a trough slides
down off the coast of Oregon and Washington State.

In response to 500 mb height trends, highs will increase
marginally each day through Friday. However, even by Friday
temperatures will still be within several degrees of normal.
Expect 70s at the beaches, 80s across the inland coastal areas and
90s in the valleys. Marine layer clouds will remain minimal over
land, and mostly be confined to the beaches along the Central
Coast each night-into- morning. Saturday, as heights fall and
onshore flow picks up, temperatures will drop down to a few
degrees below normal across much of the region and marine layer
cloud coverage may increase.

Strong north-to-south pressure gradients (3 to 4 mb) this evening
and night and again tomorrow will drive Sundowner winds across
the Santa Barbara South Coast. As is typical, winds will be
strongest for the western portion of the Santa Ynez mountains and
coasts, where gusts of 35 to 50 will be common. Across the
eastern Santa Ynez mountains and foothills sub- advisory level
gusts of 25 to 35 mph are expected this evening. A Wind Advisory
will go into effect at 6 pm this evening and last through tonight
for the Santa Barbara SW Coast and western Santa Ynez Mountains.
If wind start to pick up this afternoon, the onset time of this
advisory may be advanced. These dry and warm offshore winds will
cause daytime highs across the whole Santa Barbara South Coast
(including Santa Barbara City) to be several degrees above normal
today and tomorrow, with warm temperatures lasting into the
evening.

Elsewhere, onshore pressure gradients will continue to yield the
typical southwesterly to westerly wind gusts during the afternoons
and evenings across the Antelope Valley/foothills through the
Highway 14 Cooridor. Gusts 20 to 40 mph will be common and winds
will be the strongest Friday and Saturday, when the west- to- east
pressure gradient is highest.

No monsoonal moisture is expected to reach Los Angeles County
through Thursday. Friday and Saturday, the ensembles hint at
around a 15 percent chance of some moisture reaching LA County,
but actual thunderstorm chances still remains under 5 percent for
both days. Some high clouds or cumulus cloud build ups will be
the most likely impact of any moisture reaching the region.

.LONG TERM (SUN-WED)...14/242 PM.

A modest warming trend is generally expected in the long term,
especially Monday and Tuesday, but at this point significant heat
impacts are unlikely. The region will be in between the upper low
off the coast of the Pacific Northwest and the large high
pressure center over northern Texas. Ensembles members indicate
that there is uncertainty in the exact values of 500 mb heights
over SoCal, as well as the position of the high pressure system.
This uncertainty will lowers confidence in temperatures forecasts
and monsoonal thunderstorm chances for the Los Angeles region.
Thus, there is a small (10-20 percent) chance of heat impacts by
mid- next week, and a small chance of monsoonal moisture reaching
the region each day. At present, the thunderstorms threat remains
to the southwest of Los Angeles County, this is however subject
to adjustment as the forecast evolves.

&&

.AVIATION...14/2345Z.

At 16Z at KLAX, the marine layer was 700 ft deep. The top of the
inversion was 2400 ft with a temperature of 25 Celsius.

Very high confidence in VFR conds for KPRB, KBUR, KVNY, KPMD,
KWJF.

Moderate to high confidence in all other TAFs, except KLGB where
there is low confidence between 10Z-16Z. There is a chance of
cigs at KSBP (20%), KSMX (70%), KSBA (10%), KOXR (20%), KCMA
(20%), KSMO (30%), KLAX (40%), and KLGB (50%). Moderate confidence
in any ceilings being LIFR- IFR at KSBP, KSMX, and KSBA, and IFR-
MVFR elsewhere.

KLAX...High confidence in VFR conds through at least 06Z and after
16Z. There is a 40% chancec of OVC008-012 cigs forming as early
as 10Z and as late as 14Z. Good confidence that any east wind
component will remain under 8 kt.

KBUR...High confidence in VFR TAF.

&&

.MARINE...14/831 PM.

For the offshore waters from the Central Coast to San Nicolas
Island (the outer waters), there is a 70% chance of gales
increasing to a 90% chance for Thursday night. Winds will be
strongest during the late afternoon through late evening hours.
High confidence of SCA level winds following the gales through at
least the weekend.

For the nearshore waters of the Central Coast, moderate
confidence in SCA level winds and/or steep seas through Thursday,
especially in the afternoon and evening hours. Chances of SCA
lower Friday through the weekend.

For the Santa Barbara Channel, high confidence in SCA levels winds
over the far western portion each afternoon and evening through
Thursday, with a 50% chance of SCA winds extending across the
entire western half. Moderate confidence that the eastern portion
will stay under SCA levels. Over the weekend, there is a 40%
chance of SCA level winds over the western half of the channel
during the afternoon and evening hours.

For the waters off of Los Angeles and Orange Counties, other than
local gusts to 20 to 25 knots in the San Pedro Channel, high
confidence in conditions staying under SCA levels.

High confidence in building short period seas through Friday
morning nearly everywhere, including the nearshore waters.

With a shallow marine layer, high confidence in dense fog with
visibilities under 1 mile effecting the Central Coast waters
through the week.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...Wind Advisory in effect until 6 AM PDT Thursday for zones
      349-351. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 5 AM PDT Friday for zone
      645. (See LAXMWWLOX).
     Small Craft Advisory in effect until 3 AM PDT Thursday for
      zone 650. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Friday for zones
      670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...Schoenfeld/Rorke
AVIATION...Lund
MARINE...RK/Lewis/Lund
SYNOPSIS...RS/KL

weather.gov/losangeles

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