394
FXUS66 KLOX 081136
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
436 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)...08/431 AM.

The operational runs of both the GFS and the EC show the upper low
reversing course and shifting eastward Fri night and Sat, with an
amplifying ridge moving into the West Coast. At the surface, low
level N-S gradients will increase across SLO and SBA Counties,
possibly resulting in some gusty winds across southern SBA County
during the evening hours Fri and Sat. Low clouds may be a bit less
widespread Fri night/Sat due to the northerly flow. Also, the
marine layer may become shallow enough for clouds to be confined
to coastal areas. Max temps may edge upward slightly Sat. The
upper ridge will flatten Sun, but heights will change little, so
do not expect major changes, with night thru morning low clouds
in coastal areas and locally in the valley Sat night/Sun. Max
temps may come down a tad Sun as onshore flow increases slightly.

A weak upper low will move across the eastern Pacific Mon and over
the region Tue. With lowering heights and increasing onshore flow,
expect some cooling Mon and Tue, with more extensive night thru
morning low clouds and fog extending farther inland.

&&

.AVIATION...08/1135Z.

At 1030Z at KLAX, the marine inversion was based at 1500 feet.
The top of the inversion was 2500 feet with a temperature of
15 degrees Celsius.

Overall, moderate to high confidence in 12Z TAF package. MVFR CIGs
will impact KSMO/KLAX/KLGB thru 17Z with CAVU conditions
elsewhere. For tonight, moderate confidence in return of MVFR CIGs
for coastal/valley sites south of Point Conception, but low
confidence in timing of CIG return (could be +/- 4 hours of
current forecast). Offshore flow this morning may produce some
light turbulence/LLWS across the mountains and foothills through
20Z.

KLAX...Moderate confidence in 12Z TAF. There is a 50% chance of
MVFR CIGs 12Z-16Z. For tonight, high confidence in return of MVFR
CIGs, but low confidence in timing (could be +/- 4 hours of
current 09Z forecast). No significant easterly wind component is
expected.

KBUR...Moderate confidence in 12Z TAF. Timing of dissipation of
IFR CIGs could be as late as 17Z. For tonight, moderate
confidence in return of MVFR CIGs, but low confidence in timing
(could be +/- 4 hours of current 11Z forecast).

&&

.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
AVIATION...RAT
MARINE...RAT
SYNOPSIS...DB

weather.gov/losangeles

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