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027
FXUS66 KLOX 300519
AFDLOX

Area Forecast Discussion
National Weather Service Los Angeles/Oxnard CA
1019 PM PDT Wed May 29 2024

.SYNOPSIS...
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29/937 PM.

Weakening onshore flow beneath high pressure aloft will bring a slight
warming trend through Friday, most pronounced away from the coast.
as weak high pressure sets up over the region. Low clouds will
continue to hug the beaches each afternoon and evening, keeping
the coast near persistence. Some breezy northerly winds are
expected in the Grapevine area tonight. A deeper marine layer
depth will bring cooler temperatures are expected over the
weekend.
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&&

.SHORT TERM (TDY-FRI)...
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29/1017 PM.

Onshore flow is weakening across the area as 500 mb heights
continue to climb this evening. Low clouds and fog are mainly
confined to the southern California bight south of Point Mugu,
while the eddy circulation reorganizes. A patch does extend into
the southern Santa Barbara County. Clouds should fill in across
the southern California bight overnight, possibly extending up the
Central Coast by Thursday morning.

A northerly surface pressure, contributing to the weaker onshore
flow, should develop gusty winds through the Interstate 5 Corridor
tonight. Though winds are struggling to develop currently, the
latest NAM-WRF solutions maintain winds kicking up rapidly after
midnight. A wind advisory remains in effect through 3 am PDT.

With onshore flow weakening, a warming trend will take shape
through Friday, especially away from the coast. The most warming
will occur across the interior portions of the area. Closer to the
coast, the low clouds and onshore flow will keep temperatures
close to persistence for the next couple of days.

***From Previous Discussion***

Troughing will return over the weekend for cooler temperatures
and likely persistent marine layer that will be slow to clear.

.LONG TERM (SAT-TUE)...29/206 PM.

Following the trough passage later this weekend, weak high
pressure will return early next week for a minor warming trend,
mainly inland. Coastal areas will still be dealing with plenty of
marine layer stratus that may or may not clear completely,
especially near the coast.

The upper pattern becomes interesting the latter half of next
week as a long wave ridge sets up along the West Coast. However,
at the same time a weak upper low undercuts the ridge Wednesday
just off the Baja coast. Strong ridging across far interior
California and the Great Basin through AZ will likely bring
significant warming there and some of this warming will sneak into
the Antelope Valley and far interior SLO county with highs in the
mid 90s to near 100 beginning Wednesday. However, closer to the
coast, there will still be a moderate to strong onshore flow each
afternoon, pulling in cool ocean air (SST`s still in the high 50s
to low 60s) that will keep temperatures from climbing too much
above normal. And many beach areas will likely stay cloudy through
much of the afternoon with highs only in the mid to high 60s.
Warmer coastal valleys should get to 90 or slightly higher
starting Wednesday and lasting through the end of the week.
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&&

.AVIATION...30/0056Z.

At 00Z at KLAX, the marine layer was 1900 ft deep. The top of the
inversion was at 4100 feet with a temperature of 20 C.

High confidence in desert TAFs. Moderate confidence in Central
Coast TAFs. Low to moderate confidence in all other TAFs (sites
south of Point Conception). Flight cat changes could be off by +/-
3 hours. There is a 30% chance of IFR- LIFR cigs at KSMX from
10Z-16Z Thu. Once arrived, there is a chance that CIGs do not
clear through the period for KSBA (30%), KOXR and KCMA(40%), and KSMO,
KLGB, and KLAX (20%). There is a 20% chance of LIFR conds at KOXR
and KCMA. For KBUR and KVNY, there is a 10% chance of no cigs
developing tonight, and a 20% chance of LIFR conds from 10Z-15Z
Thu.

KLAX...Moderate confidence in TAF. Flight cat changes could be off
by +/- 3 hours. Once arrived, there is a 20% chance of CIGs not
clearing through the period. There is a 20% chance of an east
wind component of 7-8 kt from 10Z-16Z Thu.

KBUR...Moderate confidence in TAF. There is a 10% chance of no
cigs developing tonight, and a 20% chance of BKN004 cigs and vsby
of around 2SM from 10Z-15Z Thu.

&&

.MARINE...
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29/910 PM.

Moderate confidence in forecast.

Across the outer waters, winds will weaken to below Gale Force
levels tonight. Then, Small Craft Advisory (SCA) level winds/seas
are likely to last for the outer waters (70-80% chance) into
Thursday night. Below SCA level conditions are expected late
Thursday night and Friday, though seas may be close. SCA level
conditions are likely much of the time (60-70% chance) Friday
night through Monday.

Across the inner waters North of Point Sal, SCA winds and seas
will continue into late tonight and drop below SCA levels for
Thursday morning. Then, SCA conditions are likely to return (70%
chance) Thursday afternoon/evening. SCA conditions are not
expected late Thursday evening through Saturday morning. There is
50-60% chance of SCA level winds in the afternoons/evenings
Saturday through Sunday.

Across the inner waters South of Pt. Sal, there is a 30-40%
chance of SCA winds across the western portion of the Santa
Barbara Channel Saturday and Sunday afternoon/evening. Otherwise,
SCA conds are not expected.
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&&

.LOX WATCHES/WARNINGS/ADVISORIES...
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CA...Wind Advisory remains in effect until 3 AM PDT Thursday for
      zones 378-381. (See LAXNPWLOX).
PZ...Small Craft Advisory in effect until 3 AM PDT Thursday for
      zone 645. (See LAXMWWLOX).
     Gale Warning in effect until 3 AM PDT Thursday for zones
      670-673-676. (See LAXMWWLOX).
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&&

$$

PUBLIC...Hall/MW
AVIATION...Lund
MARINE...DB/Schoenfeld/Lund
SYNOPSIS...Hall

weather.gov/losangeles

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