619
FXUS66 KLOX 081118
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
418 AM PDT Wed May 8 2024

.SYNOPSIS...08/331 AM.

Gusty northeast winds will affect portions of Los Angeles and
Ventura Counties this morning and some warming is expected today.
Otherwise, a quiet weather pattern is expected through early next
week, with dry conditions. Night through morning low clouds
should become more extensive late in the weekend and early next
week. Mostly minor day to day changes in temperatures are expected
through Sunday, with some cooling possible Monday and Tuesday.

&&

.SHORT TERM (TDY-FRI)...08/418 AM.

Gusty northwest to north winds have dropped below advisory levels
in most areas, so the Wind Advisory was allowed to expire. Low
level flow has begun to turn northeasterly, and some gusty NE
winds will develop in the mountains of Ventura and L.A. County,
the northern/western valleys of L.A. County and VTU County, and
coastal sections of VTU County. There could be a few advisory
level gusts in the more wind-prone locations, but in general,
expect winds to remain below advisory levels this m morning.

A pronounced eddy circulation has developed across the inner
coastal waters. This has caused low clouds to spread northward
form the L.A. County coast into the San Gabriel Valley and eastern
portions of the San Fernando Valley, and clouds may become a bit
more widespread in the San Fernando Valley by daybreak. Patchy
low clouds and fog have also developed across southern portions of
the Central Coast. Skies are expected to clear by mid morning.
While heights and thicknesses will be a bit lower across the
region than they were on Tue, there should actually be some
warming, especially west of the mountains, thank to offshore flow
and warming at 950 mb.

The upper pattern featured a large upper low in the Great Plains
extending southwestward into Utah early this morning. A strong
rotating around the western periphery of this upper low is cause a
new upper low to form over Utah late tonight and Thu, with
troughing, and broad cyclonic flow aloft extending into the
forecast area.

The high resolution models have really keyed in on a good eddy
circulation tonight, with rather strong SE flow spreading thru
the Santa Barbara Channel tonight. By Thu morning, this will
evolve into a full blown southerly surge as southerly winds at the
surface round Pt. Conception and spread northward into and off
the Central Coast. Expect more widespread low clouds/fog in
coastal areas and in the the lower valleys tonight/Thu morning.
The question is whether or not the eddy circulation tonight shifts
westward too much, and actually pulls clouds off the coast of
L.A. County. But in general, clouds should be more widespread
tonight/Thu morning, with clearing expected in most areas by late
Thu morning. There will be a fair amount of cooling at 950 mb due
to the southeasterly flow, so expect several degrees of cooling
in most areas west of the mountains. The exception may be across
the Santa Ynez Valley and southern portions of the Central Coast,
where southerly flow will downslope, producing some warming.

The upper low will drift southwestward into southern Nevada Thu
night/Fri, but it will weaken, and heights will actually rise
across the area. Expect night thru morning low clouds in coastal
and some valley areas Thu night/Fri morning. Max temps should be
up a few degrees in most areas Fri, at least away from the coast.

.LONG TERM (SAT-TUE)...07/208 PM.

Ensemble models have a range of outcomes over the weekend,
concerning where the wobbling upper level low wants to go. The
most likely outcome is for steady increase of onshore flow
bringing more cool coastal clouds and gusty onshore winds over the
interior. To what magnitude however is still on the table. The
first half of next week, looks fairly benign, except for likely
continued strengthening of the onshore flow over the mountains and
interior, with further expansion of low clouds on the coastal
side. There are some indications of some warming for the second
half of next week with high pressure building in.

&&

.AVIATION...08/0031Z.

At 2300Z at KLAX, the marine layer was 1500 ft deep, with an
inversion top at 4300 ft and a temperature of 16 C.

Moderate confidence in the 00Z TAF package. There is a 30% chance
of no CIGs developing at KPRB, and a 30% of no CIGs for sites
KLAX/KLGB/KSMO. There is also a 20% chance of CIGs forming at KBUR
and KVNY, most likely in the IFR to low MVFR category if they do
form. The timing of flight cat changes could be off by +/- 2
hours. For KPMD and KWJF, there is a 40% chance of MVFR VSBYs in
blowing dust through 04Z.

KLAX...Moderate confidence in the 00Z TAF. Timing of cig changes
may be off by +/- 2 hours, and there is a 20-30% chance of no
cigs developing at all. An easterly wind component up to 8 knots is
expected between 09Z to 16Z, with just a 10% chance of the east
wind component reaching 10 kts during this time.

KBUR...Moderate to high confidence in the 00Z TAF. There is a 20%
chance of IFR to low MVFR CIGs forming between 12Z to 16Z.

&&

.MARINE...08/104 AM.

For the Outer Waters, high confidence in the current forecast.
Today through tonight, a combination of Small Craft Advisory (SCA0
level winds and seas are expected. For Thursday through Sunday,
winds and seas will remain below SCA levels.

For the Inner Waters north of Point Sal, moderate to high
confidence in the current forecast. For today, there is a 30%
chance of SCA level winds this afternoon and evening. For tonight
through Sunday, high confidence in winds and seas remaining below
SCA levels.

For the Inner Waters south of Point Conception, high confidence in
the current forecast. Today through Sunday, winds and seas will
remain below SCA levels. For tonight and Thursday morning,
southeasterly wind gusts of 10 to 15 knots will be possible.

&&

.LOX WATCHES/WARNINGS/ADVISORIES...
CA...High Surf Advisory in effect until 9 AM PDT Thursday for
      zones 340-346. (See LAXCFWLOX).
     Beach Hazards Statement in effect through this evening for
      zone 354. (See LAXCFWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Thursday for
      zones 670-673-676. (See LAXMWWLOX).

&&

$$

PUBLIC...DB/Kittell
AVIATION...Smith
MARINE...RAT
SYNOPSIS...DB

weather.gov/losangeles

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